Mercedes-Benz first series automatic transmission

{{short description|Motor vehicle automatic transmission models}}

{{Infobox automobile

| name = Mercedes-Benz K4A 025

K4B 050 · K4C 025 · K4A 040

W3A 040 · W3B 050 · W4B 025

W4A 018 · W4B 035

| image = K4A 025 transmission left hand side view 01.jpg

| caption = K4A 025

| production = 1961–1983

| manufacturer = Daimler AG

| class = 3 and 4-speed longitudinal automatic transmission

| successor = 4G-Tronic

}}

The Mercedes-Benz first series of automatic transmission was produced from 1961 to 1983 in 4- and 3-speed variants for Mercedes-Benz passenger cars. In addition, variants for commercial vehicles were offered.

This transmission was the first Mercedes-Benz automatic transmission in-house developing.{{cite web|title=50 years of automatic transmissions from Mercedes-Benz|url=http://media.daimler.com/marsMediaSite/en/instance/ko/50-years-of-automatic-transmissions-from-Mercedes-Benz.xhtml?oid=9915119}} Before this, the company used semi-automatic systems like a vacuum-powered shifting for overdrive or the "Hydrak" hydraulic automatic clutch system. Alternatively, they bought automatic transmissions of other vendors, such as the Detroit gear 3-speed automatic transmission from BorgWarner for the 300 c and 300 d (not to be confused with the later 300 D and its successors).

The automatic transmissions are for engines with longitudinal layout for rear-wheel-drive layout passenger cars. The control of the fully automatic system is fully hydraulic and it uses electrical wire only for the kickdown solenoid valve and the neutral safety switch.

Physically, it can be recognized for its pan which uses 16 bolts.

class="wikitable collapsible" style="text-align:center" \|+Gear Ratios{{efn\|Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage}} !{{diagonal split header\|Model\|Gear}} !R !1 !2 !3 !4 !Total Span !Span Center !Avg. Step !Compo- nents
colspan=11 style="background:#AAF;"\|
K4A 025 · 1961 \|{{round
228/55\|3}} \|{{round\|378/95\|3}} \|{{round\|63/25\|3}} \|{{round\|30/19\|3}} \|{{round\|1/1\|3}} \|{{round\|378/951/1\|3}} \|{{round\|(378/951/1)^(1/2)\|3}} \|{{round\|(378/95*1/1)^(1/3)\|3}} \|2 Gearsets 3 Brakes 3 Clutches
colspan=11 style="background:#AAF;"\|
K4B 050 · 1964 \|{{round
228/55\|3}} \|{{round\|378/95\|3}} \|{{round\|1168/475\|3}} \|{{round\|30/19\|3}} \|{{round\|1/1\|3}} \|{{round\|378/951/1\|3}} \|{{round\|(378/951/1)^(1/2)\|3}} \|{{round\|(378/95*1/1)^(1/3)\|3}} \|rowspan=4\|3 Gearsets 3 Brakes 2 Clutches
K4C 025 · 1967 K4A 040 · 1969 W4B 025 · 1972 \|{{round
2109/385\|3}} \|{{round\|1665/418\|3}} \|{{round\|5439/2280\|3}} \|{{round\|111/76\|3}} \|{{round\|1/1\|3}} \|{{round\|1665/4181/1\|3}} \|{{round\|(1665/4181/1)^(1/2)\|3}} \|{{round\|(1665/418*1/1)^(1/3)\|3}}
W4A 018 · 1975 \|{{round
4680/851\|3}} \|{{round\|7371/1840\|3}} \|{{round\|1339/560\|3}} \|{{round\|117/80\|3}} \|{{round\|1/1\|3}} \|{{round\|7371/18401/1\|3}} \|{{round\|(7371/18401/1)^(1/2)\|3}} \|{{round\|(7371/1840*1/1)^(1/3)\|3}}
W4B 035 · 1975 \|{{round
2223/378\|3}} \|{{round\|3420/819\|3}} \|{{round\|627/260\|3}} \|{{round\|57/39\|3}} \|{{round\|1/1\|3}} \|{{round\|3420/8191/1\|3}} \|{{round\|(3420/8191/1)^(1/2)\|3}} \|{{round\|(3420/819*1/1)^(1/3)\|3}}
colspan=11 style="background:#AAF;"\|
W3A 040 · 1971 W3A 050 · 1973 W3A 050 reinf. · 1975 \|{{round
1221/665\|3}} \|{{round\|1665/722\|3}} \|{{round\|111/76\|3}} \|{{round\|1/1\|3}} \|style="background:#DDF;"\| \|{{round\|1665/7221/1\|3}} \|{{round\|(1665/7221/1)^(1/2)\|3}} \|{{round\|(1665/722*1/1)^(1/2)\|3}} \|2 Gearsets 3 Brakes 2 Clutches
colspan=11 style="background:#AAF;"\|
colspan=11\|{{notelist\|2\|group=efn}}
colspan=11 style="background:#AAF;"\|

class="wikitable collapsible" style="text-align:center"

|+Gear Ratios{{efn|Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage}}

!{{diagonal split header|Model|Gear}}

!Total
Span

!Span
Center

!Avg.
Step

!Compo-
nents

colspan=11 style="background:#AAF;"|

K4A 025 · 1961

|{{round

228/55|3}}

|{{round|378/95|3}}

|{{round|63/25|3}}

|{{round|30/19|3}}

|{{round|1/1|3}}

|{{round|378/95*1/1|3}}

|{{round|(378/95*1/1)^(1/2)|3}}

|{{round|(378/95*1/1)^(1/3)|3}}

|2 Gearsets
3 Brakes
3 Clutches

colspan=11 style="background:#AAF;"|

K4B 050 · 1964

|{{round

228/55|3}}

|{{round|378/95|3}}

|{{round|1168/475|3}}

|{{round|30/19|3}}

|{{round|1/1|3}}

|{{round|378/95*1/1|3}}

|{{round|(378/95*1/1)^(1/2)|3}}

|{{round|(378/95*1/1)^(1/3)|3}}

|rowspan=4|3
Gearsets
3
Brakes
2
Clutches

K4C 025 · 1967
K4A 040 · 1969
W4B 025 · 1972

|{{round

2109/385|3}}

|{{round|1665/418|3}}

|{{round|5439/2280|3}}

|{{round|111/76|3}}

|{{round|1/1|3}}

|{{round|1665/418*1/1|3}}

|{{round|(1665/418*1/1)^(1/2)|3}}

|{{round|(1665/418*1/1)^(1/3)|3}}

W4A 018 · 1975

|{{round

4680/851|3}}

|{{round|7371/1840|3}}

|{{round|1339/560|3}}

|{{round|117/80|3}}

|{{round|1/1|3}}

|{{round|7371/1840*1/1|3}}

|{{round|(7371/1840*1/1)^(1/2)|3}}

|{{round|(7371/1840*1/1)^(1/3)|3}}

W4B 035 · 1975

|{{round

2223/378|3}}

|{{round|3420/819|3}}

|{{round|627/260|3}}

|{{round|57/39|3}}

|{{round|1/1|3}}

|{{round|3420/819*1/1|3}}

|{{round|(3420/819*1/1)^(1/2)|3}}

|{{round|(3420/819*1/1)^(1/3)|3}}

colspan=11 style="background:#AAF;"|

W3A 040 · 1971
W3A 050 · 1973
W3A 050 reinf. · 1975

|{{round

1221/665|3}}

|{{round|1665/722|3}}

|{{round|111/76|3}}

|{{round|1/1|3}}

|style="background:#DDF;"|

|{{round|1665/722*1/1|3}}

|{{round|(1665/722*1/1)^(1/2)|3}}

|2 Gearsets
3 Brakes
2 Clutches

colspan=11 style="background:#AAF;"|

colspan=11|{{notelist|2|group=efn}}

colspan=11 style="background:#AAF;"|

1961: K4A 025<br>— 4-Speed Transmission With 2 Planetary Gearsets —

File:K4A 025 transmission left hand side view 01.jpg

File:K4A 025 transmission right hand side view.jpg

= Layout =

The K4A 025{{efn|Kupplungs-4-Gang-Automatik bis 25 kpm Eingangsdrehmoment
(clutch-4-gear-automatic with {{convert|25|kpm|lbft|0|abbr=on|lk=on}} maximum input torque}} (without type designation) is the first of the series, launched in April 1961 for the W 111 220 SEb, later replaced with the more reliable K4C 025 (type 722.2). It is a 4-speed unit and uses fluid coupling (also referred in some manuals as hydraulic/automatic clutch).

The design of the transmission results in poor shifting comfort, which does not meet Mercedes-Benz standards. This applies in particular to the change from 2nd to 3rd gear (and vice versa), which requires a group change, i.e. affects all shift elements.

= Specifications =

For this first 4-speed model{{efn|plus 1 reverse gear}} 8 main components{{efn|2 simple planetary gearsets, 3 brakes, 3 clutches}} are used. It is the only exemption which uses only 2 planetary gearsets for 4 speeds.

class="wikitable collapsible" style="text-align:center" \|+Gear Ratios !colspan=2\|With Assessment !colspan=2\|Planetary Gearset: Teeth Simple{{efn\|Layout Input and output are on opposite sides Planetary gearset 1 is on the input (turbine) side Input shafts is S₁ and, if actuated, C₁ (the carrier of gearset 1) Output shaft is C₂ (the carrier of gearset 2)}} !Count !Total{{efn\|Total Ratio Span (Total Ratio Spread · Total Gear Ratio) $\tfrac{i_n} {i_1}$ A wider span enables the downspeeding when driving outside the city limits increase the climbing ability when driving over mountain passes or off-road or when towing a trailer}} Center{{efn\|Ratio Span's Center $(i_n i_1)^\tfrac{1} {2}$ The center indicates the speed level of the transmission Together with the final drive ratio it gives the shaft speed level of the vehicle}} !Avg.{{efn\|Average Gear Step $(\tfrac{i_n} {i_1})^\tfrac{1} {n-1}$ With decreasing step width the gears connect better to each other shifting comfort increases}}
colspan=7 style="background:#AAF;"\|
Model Type !Version First Delivery !S₁{{efn\|Sun 1: sun gear of gearset 1}} R₁{{efn\|Ring 1: ring gear of gearset 1}} !S₂{{efn\|Sun 2: sun gear of gearset 2}} R₂{{efn\|Ring 2: ring gear of gearset 2}} !Brakes Clutches !Ratio Span !Gear Step{{efn\|name=50:50\|Standard 50:50 — 50 % Is Above And 50 % Is Below The Average Gear Step — With steadily decreasing gear steps (yellow highlighted line Step) and a particularly large step from 1st to 2nd gear the lower half of the gear steps (between the small gears; rounded down, here the first 1) is always larger and the upper half of the gear steps (between the large gears; rounded up, here the last 2) is always smaller than the average gear step (cell highlighted yellow two rows above on the far right) lower half: {{font color\|red\|smaller gear steps are a waste of possible ratios (red bold)}} upper half: {{font color\|red\|larger gear steps are unsatisfactory (red bold)}}}}
style="font-style:italic;" !Gear Ratio ! !R ${i_R}$ !1 ${i_1}$ !2 ${i_2}$ !3 ${i_3}$ !4 ${i_4}$
Step{{efn\|name=50:50}} ! ! $-\tfrac{i_R} {i_1}$ {{efn\|name=R:1\|Standard R:1 — Reverse And 1st Gear Have The Same Ratio — The ideal reverse gear has the same transmission ratio as 1st gear no impairment when maneuvering especially when towing a trailer a torque converter can only partially compensate for this deficiency Plus 11.11 % minus 10 % compared to 1st gear is good {{font color\|red\|Plus 25 % minus 20 % is acceptable (red)}} {{font color\|red\|Above this is unsatisfactory (bold)}}}} ! $\tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_2}$ {{efn\|name=1:2\|Standard 1:2 — Gear Step 1st To 2nd Gear As Small As Possible — With continuously decreasing gear steps (yellow marked line Step) the largest gear step is the one from 1st to 2nd gear, which for a good speed connection and a smooth gear shift must be as small as possible A gear ratio of up to 1.6667:1 (5:3) is good {{font color\|red\|Up to 1.7500:1 (7:4) is acceptable (red)}} {{font color\|red\|Above is unsatisfactory (bold)}}}} ! $\tfrac{i_2} {i_3}$ ! $\tfrac{i_3} {i_4}$
Δ Step{{efn\|name=LS\|From large to small gears (from right to left)}}{{efn\|name=step\|Standard STEP — From Large To Small Gears: Steady And Progressive Increase In Gear Steps — Gear steps should increase: Δ Step (first green highlighted line Δ Step) is always greater than 1 As progressive as possible: Δ Step is always greater than the previous step {{font color\|red\|Not progressively increasing is acceptable (red)}} {{font color\|red\|Not increasing is unsatisfactory (bold)}}}} !style="background:#DDF;"\| !style="background:#DDF;"\| !style="background:#DDF;"\| ! $\tfrac{i_1} {i_2} : \tfrac{i_2} {i_3}$ ! $\tfrac{i_2} {i_3} : \tfrac{i_3} {i_4}$ !style="background:#DDF;"\|
Shaft Speed ! ! $\tfrac{i_1} {i_R}$ ! $\tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_2}$ ! $\tfrac{i_1} {i_3}$ ! $\tfrac{i_1} {i_4}$
Δ Shaft Speed{{efn\|name=speed\|Standard SPEED — From Small To Large Gears: Steady Increase In Shaft Speed Difference — Shaft speed differences should increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one {{font color\|red\|1 difference smaller than the previous one is acceptable (red)}} {{font color\|red\|2 consecutive ones are a waste of possible ratios (bold)}}}} ! ! $0 - \tfrac{i_1} {i_R}$ ! $\tfrac{i_1} {i_1} - 0$ ! $\tfrac{i_1} {i_2} - \tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_3} - \tfrac{i_1} {i_2}$ ! $\tfrac{i_1} {i_4} - \tfrac{i_1} {i_3}$
colspan=7 style="background:#AAF;"\|
K4A 025 N/A \|{{convert\|25\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1961Johannes Looman · Zahnradgetriebe · pp. 133 ff · Berlin and Heidelberg 1970 · Print {{ISBN\|978-3-540-04894-7}}Ergebnis und Ausblick · Festschrift für Herrn Prof. Dr. Hans Joachim Förster zum Ausscheiden als Direktor aus dem aktiven Dienst der Daimler-Benz AG November 1982 (Result And Outlook · commemorative publication for Prof. Dr. Hans Joachim Foerster on the occasion of leaving as director from active duty at Daimler-Benz AG November 1982) · pp. 6 · 20 \|50 76 \|44 76 \|3 3 \|{{round\|378/951/1\|4}} {{round\|(378/951/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{font color\|red\|*{{round\|(378/951/1)^(1/3)\|4}}**}}{{efn\|name=50:50}}
style="font-style:italic;" !Gear Ratio \| \|{{round
228/55\|4}} $-\tfrac{228}{55}$ \|{{round\|378/95\|4}} $\tfrac{378}{95}$ \|{{font color\|red\|{{round\|63/25\|4}}{{efn\|name=50:50}}{{efn\|name=step}} $\tfrac{63}{25}$ }} \|{{font color\|red\|{{round\|30/19\|4}}{{efn\|name=50:50}} $\tfrac{30}{19}$ }} \|1.0000 $\tfrac{1}{1}$
Step \| \|1.0418 !1.0000 \|style="background:#FFC;"\|{{font color\|red\|1.5789}}{{efn\|name=50:50}} \|style="background:#FFC;"\|{{font color\|red\|1.5960}}{{efn\|name=50:50}} \|style="background:#FFC;"\|1.5789
Δ Step{{efn\|name=LS}} \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DFD;"\|{{font color\|red\|0.9893}}{{efn\|name=step}} \|style="background:#DFD;"\|1.0108 \|style="background:#DDF;"\|
Speed \| \| -0.9598 !1.0000 \|1.5789 \|2.5200 \|3.9789
Δ Speed \| \|0.9598 !1.0000 \|style="background:#DFD;"\|0.5789 \|style="background:#DFD;"\|0.9411 \|style="background:#DFD;"\|1.4589
colspan="7" style="background:#AAF;"\|
style="font-style:italic;" !Ratio R & Even \| \|colspan=2=\| $-\tfrac{R_1 (S_2+ R_2)} {S_1 S_2}$ \|colspan=2\| $\tfrac{S_1+ R_1} {S_1}$ \| $\tfrac{1} {1}$
style="font-style:italic;" !Ratio Odd \|colspan=2\| \|colspan=2\| $\tfrac{(S_1+ R_1) (S_2+ R_2)} {S_1 R_2}$ \|colspan=2\| $\tfrac{S_2+ R_2}{R_2}$
colspan=7\|Algebra And Actuated Shift Elements
Brake A{{efn\|Blocks R₁}} \| \| \|❶ \|❶ \| \|
Brake B{{efn\|Blocks S₂}} \| \| \|❶ \| \|❶ \|
Brake R{{efn\|Blocks C₁(the carrier of gearset 1)}} \| \|❶ \| \| \| \|
Clutch D{{efn\|Couples C₁ (the carrier of gearset 2) with the turbine}} \| \| \| \| \|❶ \|❶
Clutch E{{efn\|Couples R₁ with S₂}} \| \|❶ \| \| \| \|
Clutch F{{efn\|Couples S₂ with R₂}} \| \| \| \|❶ \| \|❶
colspan="7" style="background:#AAF;"\|
colspan="7"\| {{notelist\|2\|group=efn}}
colspan="7" style="background:#AAF;"\|

class="wikitable collapsible" style="text-align:center"

|+Gear Ratios

!colspan=2|With Assessment

!colspan=2|Planetary Gearset:
Teeth Simple{{efn|Layout

Input and output are on opposite sides
Planetary gearset 1 is on the input (turbine) side
Input shafts is S₁ and, if actuated, C₁ (the carrier of gearset 1)
Output shaft is C₂ (the carrier of gearset 2)}}

!Count

!Total{{efn|Total Ratio Span (Total Ratio Spread · Total Gear Ratio)

$\tfrac{i_n} {i_1}$
A wider span enables the
downspeeding when driving outside the city limits
increase the climbing ability
when driving over mountain passes or off-road
or when towing a trailer}}
Center{{efn|Ratio Span's Center
$(i_n i_1)^\tfrac{1} {2}$
The center indicates the speed level of the transmission
Together with the final drive ratio
it gives the shaft speed level of the vehicle}}

!Avg.{{efn|Average Gear Step

$(\tfrac{i_n} {i_1})^\tfrac{1} {n-1}$
With decreasing step width
the gears connect better to each other
shifting comfort increases}}

colspan=7 style="background:#AAF;"|

Model
Type

!Version
First Delivery

!S₁{{efn|Sun 1: sun gear of gearset 1}}
R₁{{efn|Ring 1: ring gear of gearset 1}}

!S₂{{efn|Sun 2: sun gear of gearset 2}}
R₂{{efn|Ring 2: ring gear of gearset 2}}

!Brakes
Clutches

!Ratio
Span

!Gear
Step{{efn|name=50:50|Standard 50:50
— 50 % Is Above And 50 % Is Below The Average Gear Step —

With steadily decreasing gear steps (yellow highlighted line Step)
and a particularly large step from 1st to 2nd gear
the lower half of the gear steps (between the small gears; rounded down, here the first 1) is always larger
and the upper half of the gear steps (between the large gears; rounded up, here the last 2) is always smaller
than the average gear step (cell highlighted yellow two rows above on the far right)
lower half: {{font color|red|smaller gear steps are a waste of possible ratios (red bold)}}
upper half: {{font color|red|larger gear steps are unsatisfactory (red bold)}}}}

style="font-style:italic;"

!Gear
Ratio

!R
${i_R}$

!1
${i_1}$

!2
${i_2}$

!3
${i_3}$

!4
${i_4}$

Step{{efn|name=50:50}}

! $-\tfrac{i_R} {i_1}$ {{efn|name=R:1|Standard R:1
— Reverse And 1st Gear Have The Same Ratio —

The ideal reverse gear has the same transmission ratio as 1st gear
no impairment when maneuvering
especially when towing a trailer
a torque converter can only partially compensate for this deficiency
Plus 11.11 % minus 10 % compared to 1st gear is good
{{font color|red|Plus 25 % minus 20 % is acceptable (red)}}
{{font color|red|Above this is unsatisfactory (bold)}}}}

! $\tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_2}$ {{efn|name=1:2|Standard 1:2
— Gear Step 1st To 2nd Gear As Small As Possible —

With continuously decreasing gear steps (yellow marked line Step)
the largest gear step is the one from 1st to 2nd gear, which
for a good speed connection and
a smooth gear shift
must be as small as possible
A gear ratio of up to 1.6667:1 (5:3) is good
{{font color|red|Up to 1.7500:1 (7:4) is acceptable (red)}}
{{font color|red|Above is unsatisfactory (bold)}}}}

! $\tfrac{i_2} {i_3}$

! $\tfrac{i_3} {i_4}$

Δ Step{{efn|name=LS|From large to small gears (from right to left)}}{{efn|name=step|Standard STEP
— From Large To Small Gears: Steady And Progressive Increase In Gear Steps —

Gear steps should
increase: Δ Step (first green highlighted line Δ Step) is always greater than 1
As progressive as possible: Δ Step is always greater than the previous step
{{font color|red|Not progressively increasing is acceptable (red)}}
{{font color|red|Not increasing is unsatisfactory (bold)}}}}

!style="background:#DDF;"|

! $\tfrac{i_1} {i_2} : \tfrac{i_2} {i_3}$

! $\tfrac{i_2} {i_3} : \tfrac{i_3} {i_4}$

!style="background:#DDF;"|

Shaft
Speed

! $\tfrac{i_1} {i_R}$

! $\tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_2}$

! $\tfrac{i_1} {i_3}$

! $\tfrac{i_1} {i_4}$

Δ Shaft
Speed{{efn|name=speed|Standard SPEED
— From Small To Large Gears: Steady Increase In Shaft Speed Difference —

Shaft speed differences should
increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one
{{font color|red|1 difference smaller than the previous one is acceptable (red)}}
{{font color|red|2 consecutive ones are a waste of possible ratios (bold)}}}}

! $0 - \tfrac{i_1} {i_R}$

! $\tfrac{i_1} {i_1} - 0$

! $\tfrac{i_1} {i_2} - \tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_3} - \tfrac{i_1} {i_2}$

! $\tfrac{i_1} {i_4} - \tfrac{i_1} {i_3}$

colspan=7 style="background:#AAF;"|

K4A 025
N/A

|{{convert|25|kpm|lbft|0|abbr=on|lk=on}}
1961Johannes Looman · Zahnradgetriebe · pp. 133 ff · Berlin and Heidelberg 1970 · Print {{ISBN|978-3-540-04894-7}}Ergebnis und Ausblick · Festschrift für Herrn Prof. Dr. Hans Joachim Förster zum Ausscheiden als Direktor aus dem aktiven Dienst der Daimler-Benz AG November 1982 (Result And Outlook · commemorative publication for Prof. Dr. Hans Joachim Foerster on the occasion of leaving as director from active duty at Daimler-Benz AG November 1982) · pp. 6 · 20

|50
76

|44
76

|3
3

|{{round|378/95*1/1|4}}
{{round|(378/95*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{font color|red|{{round|(378/95*1/1)^(1/3)|4}}}}{{efn|name=50:50}}

style="font-style:italic;"

!Gear
Ratio

|{{round

228/55|4}}

-\tfrac{228}{55}

|{{round|378/95|4}}
$\tfrac{378}{95}$

|{{font color|red|{{round|63/25|4}}{{efn|name=50:50}}{{efn|name=step}}
$\tfrac{63}{25}$ }}

|{{font color|red|{{round|30/19|4}}{{efn|name=50:50}}
$\tfrac{30}{19}$ }}

|1.0000
$\tfrac{1}{1}$

Step

|1.0418

!1.0000

|style="background:#FFC;"|{{font color|red|1.5789}}{{efn|name=50:50}}

|style="background:#FFC;"|{{font color|red|1.5960}}{{efn|name=50:50}}

|style="background:#FFC;"|1.5789

Δ Step{{efn|name=LS}}

|style="background:#DDF;"|

|style="background:#DFD;"|{{font color|red|0.9893}}{{efn|name=step}}

|style="background:#DFD;"|1.0108

|style="background:#DDF;"|

Speed

| -0.9598

!1.0000

|1.5789

|2.5200

|3.9789

Δ Speed

|0.9598

!1.0000

|style="background:#DFD;"|0.5789

|style="background:#DFD;"|0.9411

|style="background:#DFD;"|1.4589

colspan="7" style="background:#AAF;"|

style="font-style:italic;"

!Ratio
R & Even

|colspan=2=| $-\tfrac{R_1 (S_2+ R_2)} {S_1 S_2}$

|colspan=2| $\tfrac{S_1+ R_1} {S_1}$

| $\tfrac{1} {1}$

style="font-style:italic;"

!Ratio
Odd

|colspan=2|

|colspan=2| $\tfrac{(S_1+ R_1) (S_2+ R_2)} {S_1 R_2}$

|colspan=2| $\tfrac{S_2+ R_2}{R_2}$

colspan=7|Algebra And Actuated Shift Elements

Brake A{{efn|Blocks R₁}}

|❶

Brake B{{efn|Blocks S₂}}

|❶

Brake R{{efn|Blocks C₁(the carrier of gearset 1)}}

|❶

Clutch D{{efn|Couples C₁ (the carrier of gearset 2) with the turbine}}

|❶

Clutch E{{efn|Couples R₁ with S₂}}

|❶

Clutch F{{efn|Couples S₂ with R₂}}

|❶

colspan="7" style="background:#AAF;"|

colspan="7"| {{notelist|2|group=efn}}

colspan="7" style="background:#AAF;"|

1964: K4B 050 And Follow-Up Products<br>— 4-Speed Transmissions With 3 Planetary Gearsets —

= Layout =

The Mercedes-Benz 600 from April 1964, the first post-war "Grand Mercedes", is powered by the Mercedes-Benz M100 engine.This made a gearbox for the highest demands of luxury vehicles necessary. The design of the gearbox in the range was out of the question from the outset. The introduction of the 600 was therefore taken as an opportunity to develop a completely new design for the automatic transmission.

= Models =

== 1964: K4B 050 ==

The first model with this new layout was the K4B 050 (without type designation). Beside the new layout the number of pinions is doubled from 3 to 6 to handle the much higher torque of the big block V8 engine.

== 1967: K4C 025 ==

After the satisfactory experience with the new design, it was adopted in 1967 for the new core model K4C 025 (Type 722.2) of the first automatic transmission series from Mercedes-Benz. With the small block V8 engine M 116, the K4A 040 (Type 722.2) was launched as a reinforced version of the same design.

== 1972: W4B 025 ==

When the torque converter technique was fully established, the fluid coupling was replaced by a torque converter for the smaller engines, which leads to the W4B 025 (type 722.1). Used in L4, L5 and L6 engines due to its lower torque output. In normal situations, it rests stationary in 2nd gear, but it will use 1st gear when the vehicle starts moving and throttle is applied{{cite web|title=MB Passenger Car Series 116, PDF p. 11|url=http://img.w116.org/tech/Passenger_Car_Series_116.pdf}} or if L position is selected in gear selector.

== Variants For Commercial Cars ==

The W4A 018 (type 720.1) was derived from the W4B 025 (type 722.1) for vans up to {{convert|5600|kg|lb|-1|abbr=on|lk=on}}Ergebnis und Ausblick · Festschrift für Herrn Prof. Dr. Hans Joachim Förster zum Ausscheiden als Direktor aus dem aktiven Dienst der Daimler-Benz AG November 1982 (Result And Outlook · commemorative publication for Prof. Dr. Hans Joachim Foerster on the occasion of leaving as director from active duty at Daimler-Benz AG November 1982) · pp. 7 · 20 and off road vehicles, the W4B 035 from the W4B 025 (type 722.1) and K4A 040 (type 722.2) for light trucks up to {{convert|13000|kg|lb|-1|abbr=on|lk=on}}.Ergebnis und Ausblick · Festschrift für Herrn Prof. Dr. Hans Joachim Förster zum Ausscheiden als Direktor aus dem aktiven Dienst der Daimler-Benz AG November 1982 (Result And Outlook · commemorative publication for Prof. Dr. Hans Joachim Foerster on the occasion of leaving as director from active duty at Daimler-Benz AG November 1982) · pp. 9 · 22 The main difference is the use of straight-cut planetary gearsets instead of helical-cut ones for better fuel efficiency at the price of lower noise comfort.

=Specifications=

For this second 4-speed models{{efn|plus 1 reverse gear}} 8 main components{{efn|3 simple planetary gearsets, 3 brakes, 2 clutches}} are used.{{cite web|title=MB Passenger Car Series 116, PDF p. 10|url=http://img.w116.org/tech/Passenger_Car_Series_116.pdf}}

class="wikitable collapsible" style="text-align:center" \|+Gear Ratios !rowspan=2 colspan=2\|With Assessment !colspan=3\|Planetary Gearset: Teeth{{efn\|Layout Input and output are on opposite sides Planetary gearset 1 is on the input (turbine) side Input shafts is S₁ Output shaft is C₃ (the carrier of gearset 3)}} !rowspan=2\|Count !rowspan=2\|Total{{efn\|Total Ratio Span (Total Ratio Spread · Total Gear Ratio) $\tfrac{i_n} {i_1}$ A wider span enables the downspeeding when driving outside the city limits increase the climbing ability when driving over mountain passes or off-road or when towing a trailer}} Center{{efn\|Ratio Span's Center $(i_n i_1)^\tfrac{1} {2}$ The center indicates the speed level of the transmission Together with the final drive ratio it gives the shaft speed level of the vehicle}} !rowspan=2\|Avg.{{efn\|Average Gear Step $(\tfrac{i_n} {i_1})^\tfrac{1} {n-1}$ With decreasing step width the gears connect better to each other shifting comfort increases}}
colspan=2\|Simpson !Simple
colspan=8 style="background:#AAF;"\|
Model Type !Version First Delivery !S₁{{efn\|Sun 1: sun gear of gearset 1}} R₁{{efn\|Ring 1: ring gear of gearset 1}} !S₂{{efn\|Sun 2: sun gear of gearset 2}} R₂{{efn\|Ring 2: ring gear of gearset 2}} !S₃{{efn\|Sun 3: sun gear of gearset 3}} R₃{{efn\|Ring 3: ring gear of gearset 3}} !Brakes Clutches !Ratio Span !Gear Step{{efn\|name=50:50\|Standard 50:50 — 50 % Is Above And 50 % Is Below The Average Gear Step — With steadily decreasing gear steps (yellow highlighted line Step) and a particularly large step from 1st to 2nd gear the lower half of the gear steps (between the small gears; rounded down, here the first 1) is always larger and the upper half of the gear steps (between the large gears; rounded up, here the last 2) is always smaller than the average gear step (cell highlighted yellow two rows above on the far right) lower half: {{font color\|red\|smaller gear steps are a waste of possible ratios (red bold)}} upper half: {{font color\|red\|larger gear steps are unsatisfactory (red bold)}}}}
style="font-style:italic;" !Gear Ratio ! !R ${i_R}$ ! !1 ${i_1}$ !2 ${i_2}$ !3 ${i_3}$ !4 ${i_4}$
Step{{efn\|name=50:50}} ! ! $-\tfrac{i_R} {i_1}$ {{efn\|name=R:1\|Standard R:1 — Reverse And 1st Gear Have The Same Ratio — The ideal reverse gear has the same transmission ratio as 1st gear no impairment when maneuvering especially when towing a trailer a torque converter can only partially compensate for this deficiency Plus 11.11 % minus 10 % compared to 1st gear is good {{font color\|red\|Plus 25 % minus 20 % is acceptable (red)}} {{font color\|red\|Above this is unsatisfactory (bold)}}}} ! ! $\tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_2}$ {{efn\|name=1:2\|Standard 1:2 — Gear Step 1st To 2nd Gear As Small As Possible — With continuously decreasing gear steps (yellow marked line Step) the largest gear step is the one from 1st to 2nd gear, which for a good speed connection and a smooth gear shift must be as small as possible A gear ratio of up to 1.6667:1 (5:3) is good {{font color\|red\|Up to 1.7500:1 (7:4) is acceptable (red)}} {{font color\|red\|Above is unsatisfactory (bold)}}}} ! $\tfrac{i_2} {i_3}$ ! $\tfrac{i_3} {i_4}$
Δ Step{{efn\|name=LS\|From large to small gears (from right to left)}}{{efn\|name=step\|Standard STEP — From Large To Small Gears: Steady And Progressive Increase In Gear Steps — Gear steps should increase: Δ Step (first green highlighted line Δ Step) is always greater than 1 As progressive as possible: Δ Step is always greater than the previous step {{font color\|red\|Not progressively increasing is acceptable (red)}} {{font color\|red\|Not increasing is unsatisfactory (bold)}}}} !style="background:#DDF;"\| !style="background:#DDF;"\| !style="background:#DDF;"\| !style="background:#DDF;"\| ! $\tfrac{i_1} {i_2} : \tfrac{i_2} {i_3}$ ! $\tfrac{i_2} {i_3} : \tfrac{i_3} {i_4}$ !style="background:#DDF;"\|
Shaft Speed ! ! $\tfrac{i_1} {i_R}$ ! ! $\tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_2}$ ! $\tfrac{i_1} {i_3}$ ! $\tfrac{i_1} {i_4}$
Δ Shaft Speed{{efn\|name=speed\|Standard SPEED — From Small To Large Gears: Steady Increase In Shaft Speed Difference — Shaft speed differences should increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one {{font color\|red\|1 difference smaller than the previous one is acceptable (red)}} {{font color\|red\|2 consecutive ones are a waste of possible ratios (bold)}}}} ! ! $0 - \tfrac{i_1} {i_R}$ ! ! $\tfrac{i_1} {i_1} - 0$ ! $\tfrac{i_1} {i_2} - \tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_3} - \tfrac{i_1} {i_2}$ ! $\tfrac{i_1} {i_4} - \tfrac{i_1} {i_3}$
colspan=8 style="background:#AAF;"\|
K4B 050 N/A \|{{convert\|51\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1964 \|50 76 \|44 76 \|44 76 \|3 2 \|{{round\|378/951/1\|4}} {{round\|(378/951/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{round\|(378/95*1/1)^(1/3)\|4}}{{efn\|name=50:50}}
style="font-style:italic;" !Gear Ratio \| \|{{round
228/55\|4}} $-\tfrac{228}{55}$ \| \|{{round\|378/95\|4}} $\tfrac{378}{95}$ \|{{round\|1168/475\|4}} $\tfrac{1,168}{475}$ \|{{font color\|red\|{{round\|30/19\|4}}}}{{efn\|name=step}} \|1.0000 $\tfrac{1}{1}$
Step \| \|1.0418 \| !1.0000 \|style="background:#FFC;"\|1.6182 \|style="background:#FFC;"\|{{font color\|red\|1.5573}} \|style="background:#FFC;"\|1.5789
Δ Step{{efn\|name=LS}} \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DFD;"\|1.0391 \|style="background:#DFD;"\|{{font color\|red\|0.9863}}{{efn\|name=step}} \|style="background:#DDF;"\|
Speed \| \| -0.9598 \| !1.0000 \|1.6182 \|2.5200 \|3.9789
Δ Speed \| \|0.9598 \| !1.0000 \|style="background:#DFD;"\|0.6182 \|style="background:#DFD;"\|0.9018 \|style="background:#DFD;"\|1.4589
colspan="8" \|
K4C 025 722.2 \|{{convert\|25\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1967 \|44 76 \|44 76 \|35 76 \|3 2 \|{{round\|1665/4181/1\|4}} {{round\|(1665/4181/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{font color\|red\|*{{round\|(1665/4181/1)^(1/3)\|4}}**}}{{efn\|name=50:50}}
style="font-style:italic;" !Gear Ratio \| \|{{font color\|red\|{{round
2109/385\|4}}{{efn\|name=R:1}} $-\tfrac{2,109}{385}$ }} \| \|{{round\|1665/418\|4}} $\tfrac{1,665}{418}$ \|{{font color\|red\|{{round\|5439/2280\|4}}{{efn\|name=1:2}}{{efn\|name=step}} $\tfrac{5,439}{2,280}$ }} \|{{font color\|red\|{{round\|111/76\|4}}{{efn\|name=50:50}} $\tfrac{111}{76}$ }} \|1.0000 $\tfrac{1}{1}$
Step \| \|{{font color\|red\|1.3752}}{{efn\|name=R:1}} \| !1.0000 \|style="background:#FFC;"\|{{font color\|red\|1.6698}}{{efn\|name=1:2}} \|style="background:#FFC;"\|{{font color\|red\|1.6333}}{{efn\|name=50:50}} \|style="background:#FFC;"\|1.4605
Δ Step{{efn\|name=LS}} \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DFD;"\|{{font color\|red\|1.0223}}{{efn\|name=step}} \|style="background:#DFD;"\|1.1183 \|style="background:#DDF;"\|
Speed \| \|{{font color\|red\|-0.7271}} \| !1.0000 \|1.6696 \|2.7273 \|3.9833
Δ Speed \| \|{{font color\|red\|0.7271}} \| !1.0000 \|style="background:#DFD;"\|0.6696 \|style="background:#DFD;"\|1.0575 \|style="background:#DFD;"\|1.2560
colspan="8" \|
K4A 040 722.2 \|{{convert\|40\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1969 \|44 76 \|44 76 \|35 76 \|3 2 \|{{round\|1665/4181/1\|4}} {{round\|(1665/4181/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{font color\|red\|*{{round\|(1665/4181/1)^(1/3)\|4}}**}}{{efn\|name=50:50}}
style="font-style:italic;" !Ratio \| \|{{font color\|red\|{{round
2109/385\|4}}{{efn\|name=R:1}}}} \| \|{{round\|1665/418\|4}} \|{{font color\|red\|{{round\|5439/2280\|4}}{{efn\|name=1:2}}{{efn\|name=step}}}} \|{{font color\|red\|{{round\|111/76\|4}}{{efn\|name=50:50}}}} \|1.0000
colspan="8" \|
W4B 025 722.1 \|{{convert\|25\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1972 \|44 76 \|44 76 \|35 76 \|3 2 \|{{round\|1665/4181/1\|4}} {{round\|(1665/4181/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{font color\|red\|*{{round\|(1665/4181/1)^(1/3)\|4}}**}}{{efn\|name=50:50}}
style="font-style:italic;" !Ratio \| \|{{font color\|red\|{{round
2109/385\|4}}{{efn\|name=R:1}}}} \| \|{{round\|1665/418\|4}} \|{{font color\|red\|{{round\|5439/2280\|4}}{{efn\|name=1:2}}{{efn\|name=step}}}} \|{{font color\|red\|{{round\|111/76\|4}}{{efn\|name=50:50}}}} \|1.0000
colspan="8" \|
W4A 018{{efn\|for light duty trucks up to {{convert\|5600\|kg\|lb
1\|abbr=on\|lk=on}}Hans Joachim Foerster · Automatische Fahrzeuggetriebe · p. 487 · Berlin and Heidelberg 1991 · Print {{ISBN\|978-3-642-84119-4}} · Online {{ISBN\|978-3-642-84118-7}}}} 720.1 \|{{convert\|18\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1975 \|46 80 \|46 80 \|37 80 \|3 2 \|{{round\|7371/18401/1\|4}} {{round\|(7371/18401/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{font color\|red\|*{{round\|(7371/18401/1)^(1/3)\|4}}**}}{{efn\|name=50:50}}
style="font-style:italic;" !Gear Ratio \| \|{{font color\|red\|{{round
4680/851\|4}}{{efn\|name=R:1}} $-\tfrac{4,680}{851}$ }} \| \|{{round\|7371/1840\|4}} $\tfrac{7,371}{1840}$ \|{{font color\|red\|{{round\|1339/560\|4}}{{efn\|name=1:2}}{{efn\|name=step}} $\tfrac{1,339}{560}$ }} \|{{font color\|red\|{{round\|117/80\|4}}{{efn\|name=50:50}} $\tfrac{117}{80}$ }} \|1.0000 $\tfrac{1}{1}$
Step \| \|{{font color\|red\|1.3728}}{{efn\|name=R:1}} \| !1.0000 \|style="background:#FFC;"\|{{font color\|red\|1.6754}}{{efn\|name=1:2}} \|style="background:#FFC;"\|{{font color\|red\|1.6349}}{{efn\|name=50:50}} \|style="background:#FFC;"\|1.4625
Δ Step{{efn\|name=LS}} \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DFD;"\|{{font color\|red\|1.0248}}{{efn\|name=step}} \|style="background:#DFD;"\|1.1179 \|style="background:#DDF;"\|
Speed \| \|{{font color\|red\|-0.7284}} \| !1.0000 \|1.6754 \|2.7391 \|4.0060
Δ Speed \| \|{{font color\|red\|0.7284}} \| !1.0000 \|style="background:#DFD;"\|0.6754 \|style="background:#DFD;"\|1.0637 \|style="background:#DFD;"\|1.2668
colspan="8" \|
W4B 035{{efn\|for medium duty trucks up to {{convert\|13000\|kg\|lb
1\|abbr=on\|lk=on}}Hans Joachim Foerster · Automatische Fahrzeuggetriebe · p. 489 · Berlin and Heidelberg 1991 · Print {{ISBN\|978-3-642-84119-4}} · Online {{ISBN\|978-3-642-84118-7}}}} N/A \|{{convert\|35\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1975 \|42 78 \|42 78 \|36 78 \|3 2 \|{{round\|3420/8191/1\|4}} {{round\|(3420/8191/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{font color\|red\|*{{round\|(3420/8191/1)^(1/3)\|4}}**}}{{efn\|name=50:50}}
style="font-style:italic;" !Gear Ratio \| \|{{font color\|red\|{{round
2223/378\|4}}{{efn\|name=R:1}} $-\tfrac{2,223}{378}$ }} \| \|{{round\|3420/819\|4}} $\tfrac{3,420}{819}$ \|{{font color\|red\|{{round\|627/260\|4}}{{efn\|name=1:2}}{{efn\|name=step}} $\tfrac{627}{260}$ }} \|{{font color\|red\|{{round\|57/39\|4}}{{efn\|name=50:50}} $\tfrac{57}{39}$ }} \|1.0000 $\tfrac{1}{1}$
Step \| \|{{font color\|red\|1.4083}}{{efn\|name=R:1}} \| !1.0000 \|style="background:#FFC;"\|{{font color\|red\|1.7360}}{{efn\|name=1:2}} \|style="background:#FFC;"\|{{font color\|red\|1.6500}}{{efn\|name=50:50}} \|style="background:#FFC;"\|1.4615
Δ Step{{efn\|name=LS}} \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DFD;"\|{{font color\|red\|1.0495}}{{efn\|name=step}} \|style="background:#DFD;"\|1.1289 \|style="background:#DDF;"\|
Speed \| \|{{font color\|red\|-0.7101}} \| !1.0000 \|1.7316 \|2.8571 \|4.1758
Δ Speed \| \|{{font color\|red\|0.7101}} \| !1.0000 \|style="background:#DFD;"\|0.7316 \|style="background:#DFD;"\|1.1255 \|style="background:#DFD;"\|1.3187
colspan="8" style="background:#AAF;"\|
style="font-style:italic;" !Ratio R & Even \| \|colspan=2\| $-\tfrac{R_1 (S_3+ R_3)} {S_1 S_3}$ \|colspan=3\| $\tfrac{(S_1 (S_2+ R_2)+ R_1 S_2) (S_3+ R_3)} {S_1 (S_2+ R_2) R_3}$ \| $\tfrac{1} {1}$
style="font-style:italic;" !Ratio Odd \|colspan=2\| \|colspan=3\| $i_1 = \tfrac{(S_1+ R_1) (S_3+ R_3)} {S_1 R_3}$ \|colspan=2\| $i_3 = \tfrac{S_3+ R_3} {R_3}$
colspan=8\|Algebra And Actuated Shift Elements
Brake A{{efn\|Blocks S₂}} \| \| \| \| \|❶ \| \|
Brake B{{efn\|Blocks S₃}} \| \| \| \|❶ \|❶ \|❶ \|
Brake R{{efn\|Blocks C₁(the carrier of gearset 1)}} \| \|❶ \| \| \| \| \|
Clutch D{{efn\|Couples S₂ with C₂ (the carrier of gearset 2)}} \| \| \| \| \| \|❶ \|❶
Clutch E{{efn\|Couples R₁ with S₃}} \| \|❶ \| \|❶ \| \| \|❶
colspan="8" style="background:#AAF;"\|
colspan="8"\| {{notelist\|2\|group=efn}}
colspan="8" style="background:#AAF;"\|

class="wikitable collapsible" style="text-align:center"

|+Gear Ratios

!rowspan=2 colspan=2|With Assessment

!colspan=3|Planetary Gearset: Teeth{{efn|Layout

Input and output are on opposite sides
Planetary gearset 1 is on the input (turbine) side
Input shafts is S₁
Output shaft is C₃ (the carrier of gearset 3)}}

!rowspan=2|Count

!rowspan=2|Total{{efn|Total Ratio Span (Total Ratio Spread · Total Gear Ratio)

$\tfrac{i_n} {i_1}$
A wider span enables the
downspeeding when driving outside the city limits
increase the climbing ability
when driving over mountain passes or off-road
or when towing a trailer}}
Center{{efn|Ratio Span's Center
$(i_n i_1)^\tfrac{1} {2}$
The center indicates the speed level of the transmission
Together with the final drive ratio
it gives the shaft speed level of the vehicle}}

!rowspan=2|Avg.{{efn|Average Gear Step

$(\tfrac{i_n} {i_1})^\tfrac{1} {n-1}$
With decreasing step width
the gears connect better to each other
shifting comfort increases}}

colspan=2|Simpson

!Simple

colspan=8 style="background:#AAF;"|

Model
Type

!Version
First Delivery

!S₁{{efn|Sun 1: sun gear of gearset 1}}
R₁{{efn|Ring 1: ring gear of gearset 1}}

!S₂{{efn|Sun 2: sun gear of gearset 2}}
R₂{{efn|Ring 2: ring gear of gearset 2}}

!S₃{{efn|Sun 3: sun gear of gearset 3}}
R₃{{efn|Ring 3: ring gear of gearset 3}}

!Brakes
Clutches

!Ratio
Span

!Gear
Step{{efn|name=50:50|Standard 50:50
— 50 % Is Above And 50 % Is Below The Average Gear Step —

With steadily decreasing gear steps (yellow highlighted line Step)
and a particularly large step from 1st to 2nd gear
the lower half of the gear steps (between the small gears; rounded down, here the first 1) is always larger
and the upper half of the gear steps (between the large gears; rounded up, here the last 2) is always smaller
than the average gear step (cell highlighted yellow two rows above on the far right)
lower half: {{font color|red|smaller gear steps are a waste of possible ratios (red bold)}}
upper half: {{font color|red|larger gear steps are unsatisfactory (red bold)}}}}

style="font-style:italic;"

!Gear
Ratio

!R
${i_R}$

!1
${i_1}$

!2
${i_2}$

!3
${i_3}$

!4
${i_4}$

Step{{efn|name=50:50}}

! $-\tfrac{i_R} {i_1}$ {{efn|name=R:1|Standard R:1
— Reverse And 1st Gear Have The Same Ratio —

The ideal reverse gear has the same transmission ratio as 1st gear
no impairment when maneuvering
especially when towing a trailer
a torque converter can only partially compensate for this deficiency
Plus 11.11 % minus 10 % compared to 1st gear is good
{{font color|red|Plus 25 % minus 20 % is acceptable (red)}}
{{font color|red|Above this is unsatisfactory (bold)}}}}

! $\tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_2}$ {{efn|name=1:2|Standard 1:2
— Gear Step 1st To 2nd Gear As Small As Possible —

With continuously decreasing gear steps (yellow marked line Step)
the largest gear step is the one from 1st to 2nd gear, which
for a good speed connection and
a smooth gear shift
must be as small as possible
A gear ratio of up to 1.6667:1 (5:3) is good
{{font color|red|Up to 1.7500:1 (7:4) is acceptable (red)}}
{{font color|red|Above is unsatisfactory (bold)}}}}

! $\tfrac{i_2} {i_3}$

! $\tfrac{i_3} {i_4}$

Δ Step{{efn|name=LS|From large to small gears (from right to left)}}{{efn|name=step|Standard STEP
— From Large To Small Gears: Steady And Progressive Increase In Gear Steps —

Gear steps should
increase: Δ Step (first green highlighted line Δ Step) is always greater than 1
As progressive as possible: Δ Step is always greater than the previous step
{{font color|red|Not progressively increasing is acceptable (red)}}
{{font color|red|Not increasing is unsatisfactory (bold)}}}}

!style="background:#DDF;"|

! $\tfrac{i_1} {i_2} : \tfrac{i_2} {i_3}$

! $\tfrac{i_2} {i_3} : \tfrac{i_3} {i_4}$

!style="background:#DDF;"|

Shaft
Speed

! $\tfrac{i_1} {i_R}$

! $\tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_2}$

! $\tfrac{i_1} {i_3}$

! $\tfrac{i_1} {i_4}$

Δ Shaft
Speed{{efn|name=speed|Standard SPEED
— From Small To Large Gears: Steady Increase In Shaft Speed Difference —

Shaft speed differences should
increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one
{{font color|red|1 difference smaller than the previous one is acceptable (red)}}
{{font color|red|2 consecutive ones are a waste of possible ratios (bold)}}}}

! $0 - \tfrac{i_1} {i_R}$

! $\tfrac{i_1} {i_1} - 0$

! $\tfrac{i_1} {i_2} - \tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_3} - \tfrac{i_1} {i_2}$

! $\tfrac{i_1} {i_4} - \tfrac{i_1} {i_3}$

colspan=8 style="background:#AAF;"|

K4B 050
N/A

|{{convert|51|kpm|lbft|0|abbr=on|lk=on}}
1964

|50
76

|44
76

|3
2

|{{round|378/95*1/1|4}}
{{round|(378/95*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{round|(378/95*1/1)^(1/3)|4}}{{efn|name=50:50}}

style="font-style:italic;"

!Gear
Ratio

|{{round

228/55|4}}

-\tfrac{228}{55}

|{{round|378/95|4}}
$\tfrac{378}{95}$

|{{round|1168/475|4}}
$\tfrac{1,168}{475}$

|{{font color|red|{{round|30/19|4}}}}{{efn|name=step}}

|1.0000
$\tfrac{1}{1}$

Step

|1.0418

!1.0000

|style="background:#FFC;"|1.6182

|style="background:#FFC;"|{{font color|red|1.5573}}

|style="background:#FFC;"|1.5789

Δ Step{{efn|name=LS}}

|style="background:#DDF;"|

|style="background:#DFD;"|1.0391

|style="background:#DFD;"|{{font color|red|0.9863}}{{efn|name=step}}

|style="background:#DDF;"|

Speed

| -0.9598

!1.0000

|1.6182

|2.5200

|3.9789

Δ Speed

|0.9598

!1.0000

|style="background:#DFD;"|0.6182

|style="background:#DFD;"|0.9018

|style="background:#DFD;"|1.4589

colspan="8" |

K4C 025
722.2

|{{convert|25|kpm|lbft|0|abbr=on|lk=on}}
1967

|44
76

|35
76

|3
2

|{{round|1665/418*1/1|4}}
{{round|(1665/418*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{font color|red|{{round|(1665/418*1/1)^(1/3)|4}}}}{{efn|name=50:50}}

style="font-style:italic;"

!Gear
Ratio

|{{font color|red|{{round

2109/385|4}}{{efn|name=R:1}}

-\tfrac{2,109}{385}

}}

|{{round|1665/418|4}}
$\tfrac{1,665}{418}$

|{{font color|red|{{round|5439/2280|4}}{{efn|name=1:2}}{{efn|name=step}}
$\tfrac{5,439}{2,280}$ }}

|{{font color|red|{{round|111/76|4}}{{efn|name=50:50}}
$\tfrac{111}{76}$ }}

|1.0000
$\tfrac{1}{1}$

Step

|{{font color|red|1.3752}}{{efn|name=R:1}}

!1.0000

|style="background:#FFC;"|{{font color|red|1.6698}}{{efn|name=1:2}}

|style="background:#FFC;"|{{font color|red|1.6333}}{{efn|name=50:50}}

|style="background:#FFC;"|1.4605

Δ Step{{efn|name=LS}}

|style="background:#DDF;"|

|style="background:#DFD;"|{{font color|red|1.0223}}{{efn|name=step}}

|style="background:#DFD;"|1.1183

|style="background:#DDF;"|

Speed

|{{font color|red|-0.7271}}

!1.0000

|1.6696

|2.7273

|3.9833

Δ Speed

|{{font color|red|0.7271}}

!1.0000

|style="background:#DFD;"|0.6696

|style="background:#DFD;"|1.0575

|style="background:#DFD;"|1.2560

colspan="8" |

K4A 040
722.2

|{{convert|40|kpm|lbft|0|abbr=on|lk=on}}
1969

|44
76

|35
76

|3
2

|{{round|1665/418*1/1|4}}
{{round|(1665/418*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{font color|red|{{round|(1665/418*1/1)^(1/3)|4}}}}{{efn|name=50:50}}

style="font-style:italic;"

!Ratio

|{{font color|red|{{round

2109/385|4}}{{efn|name=R:1}}}}

|{{round|1665/418|4}}

|{{font color|red|{{round|5439/2280|4}}{{efn|name=1:2}}{{efn|name=step}}}}

|{{font color|red|{{round|111/76|4}}{{efn|name=50:50}}}}

|1.0000

colspan="8" |

W4B 025
722.1

|{{convert|25|kpm|lbft|0|abbr=on|lk=on}}
1972

|44
76

|35
76

|3
2

|{{round|1665/418*1/1|4}}
{{round|(1665/418*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{font color|red|{{round|(1665/418*1/1)^(1/3)|4}}}}{{efn|name=50:50}}

style="font-style:italic;"

!Ratio

|{{font color|red|{{round

2109/385|4}}{{efn|name=R:1}}}}

|{{round|1665/418|4}}

|{{font color|red|{{round|5439/2280|4}}{{efn|name=1:2}}{{efn|name=step}}}}

|{{font color|red|{{round|111/76|4}}{{efn|name=50:50}}}}

|1.0000

colspan="8" |

W4A 018{{efn|for light duty trucks up to {{convert|5600|kg|lb

1|abbr=on|lk=on}}Hans Joachim Foerster · Automatische Fahrzeuggetriebe · p. 487 · Berlin and Heidelberg 1991 · Print {{ISBN|978-3-642-84119-4}} · Online {{ISBN|978-3-642-84118-7}}}}
720.1

|{{convert|18|kpm|lbft|0|abbr=on|lk=on}}
1975

|46
80

|37
80

|3
2

|{{round|7371/1840*1/1|4}}
{{round|(7371/1840*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{font color|red|{{round|(7371/1840*1/1)^(1/3)|4}}}}{{efn|name=50:50}}

style="font-style:italic;"

!Gear
Ratio

|{{font color|red|{{round

4680/851|4}}{{efn|name=R:1}}

-\tfrac{4,680}{851}

}}

|{{round|7371/1840|4}}
$\tfrac{7,371}{1840}$

|{{font color|red|{{round|1339/560|4}}{{efn|name=1:2}}{{efn|name=step}}
$\tfrac{1,339}{560}$ }}

|{{font color|red|{{round|117/80|4}}{{efn|name=50:50}}
$\tfrac{117}{80}$ }}

|1.0000
$\tfrac{1}{1}$

Step

|{{font color|red|1.3728}}{{efn|name=R:1}}

!1.0000

|style="background:#FFC;"|{{font color|red|1.6754}}{{efn|name=1:2}}

|style="background:#FFC;"|{{font color|red|1.6349}}{{efn|name=50:50}}

|style="background:#FFC;"|1.4625

Δ Step{{efn|name=LS}}

|style="background:#DDF;"|

|style="background:#DFD;"|{{font color|red|1.0248}}{{efn|name=step}}

|style="background:#DFD;"|1.1179

|style="background:#DDF;"|

Speed

|{{font color|red|-0.7284}}

!1.0000

|1.6754

|2.7391

|4.0060

Δ Speed

|{{font color|red|0.7284}}

!1.0000

|style="background:#DFD;"|0.6754

|style="background:#DFD;"|1.0637

|style="background:#DFD;"|1.2668

colspan="8" |

W4B 035{{efn|for medium duty trucks up to {{convert|13000|kg|lb

1|abbr=on|lk=on}}Hans Joachim Foerster · Automatische Fahrzeuggetriebe · p. 489 · Berlin and Heidelberg 1991 · Print {{ISBN|978-3-642-84119-4}} · Online {{ISBN|978-3-642-84118-7}}}}
N/A

|{{convert|35|kpm|lbft|0|abbr=on|lk=on}}
1975

|42
78

|36
78

|3
2

|{{round|3420/819*1/1|4}}
{{round|(3420/819*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{font color|red|{{round|(3420/819*1/1)^(1/3)|4}}}}{{efn|name=50:50}}

style="font-style:italic;"

!Gear
Ratio

|{{font color|red|{{round

2223/378|4}}{{efn|name=R:1}}

-\tfrac{2,223}{378}

}}

|{{round|3420/819|4}}
$\tfrac{3,420}{819}$

|{{font color|red|{{round|627/260|4}}{{efn|name=1:2}}{{efn|name=step}}
$\tfrac{627}{260}$ }}

|{{font color|red|{{round|57/39|4}}{{efn|name=50:50}}
$\tfrac{57}{39}$ }}

|1.0000
$\tfrac{1}{1}$

Step

|{{font color|red|1.4083}}{{efn|name=R:1}}

!1.0000

|style="background:#FFC;"|{{font color|red|1.7360}}{{efn|name=1:2}}

|style="background:#FFC;"|{{font color|red|1.6500}}{{efn|name=50:50}}

|style="background:#FFC;"|1.4615

Δ Step{{efn|name=LS}}

|style="background:#DDF;"|

|style="background:#DFD;"|{{font color|red|1.0495}}{{efn|name=step}}

|style="background:#DFD;"|1.1289

|style="background:#DDF;"|

Speed

|{{font color|red|-0.7101}}

!1.0000

|1.7316

|2.8571

|4.1758

Δ Speed

|{{font color|red|0.7101}}

!1.0000

|style="background:#DFD;"|0.7316

|style="background:#DFD;"|1.1255

|style="background:#DFD;"|1.3187

colspan="8" style="background:#AAF;"|

style="font-style:italic;"

!Ratio
R & Even

|colspan=2| $-\tfrac{R_1 (S_3+ R_3)} {S_1 S_3}$

|colspan=3| $\tfrac{(S_1 (S_2+ R_2)+ R_1 S_2) (S_3+ R_3)} {S_1 (S_2+ R_2) R_3}$

| $\tfrac{1} {1}$

style="font-style:italic;"

!Ratio
Odd

|colspan=2|

|colspan=3| $i_1 = \tfrac{(S_1+ R_1) (S_3+ R_3)} {S_1 R_3}$

|colspan=2| $i_3 = \tfrac{S_3+ R_3} {R_3}$

colspan=8|Algebra And Actuated Shift Elements

Brake A{{efn|Blocks S₂}}

|❶

Brake B{{efn|Blocks S₃}}

|❶

Brake R{{efn|Blocks C₁(the carrier of gearset 1)}}

|❶

Clutch D{{efn|Couples S₂ with C₂ (the carrier of gearset 2)}}

|❶

Clutch E{{efn|Couples R₁ with S₃}}

|❶

colspan="8" style="background:#AAF;"|

colspan="8"| {{notelist|2|group=efn}}

colspan="8" style="background:#AAF;"|

1971: W3A 040 And Follow-Up Products<br>— 3-Speed Transmissions With 2 Planetary Gearsets —

=Layout=

When the torque converter technique was fully established, 3-speed units, the W3A 040 and W3B 050 (type 722.0) is combined with V8 engines, and it uses torque converter instead of fluid coupling. The transmission saves 1 planetary gearset and uses the same housing as the 4-speed versions. The free space therefore is used to reinforce the shift elements (brakes and clutches) to handle the higher torque of the V8 engines.

First the W3A 040 was released for the all new M117 V8 engine of the W 108 and W 109 in 1971. The second in the series is the W3B 050, which was released initially for the W 116 450 SE/SEL in 1973. At that time the 4-speed transmission for the 350 SE/SEL was replaced by this 3-speed model. The reinforced W3B 050 reinforced (type 722.003) is the strongest of the series, able to handle the input of the enlarged version of the M 100, the biggest Mercedes-Benz engine in post-war history,Only surpassed by the Mercedes-Benz 770, built from 1930 to 1943 exclusively used in the W 116 450 SEL 6.9.

=Specifications=

For the 3-speed models{{efn|plus 1 reverse gear}} 7 main components{{efn|2 simple planetary gearsets, 3 brakes, 2 clutches}} are used, which shows economic equivalence with the direct competitor.

class="wikitable collapsible" style="text-align:center" \|+Gear Ratios !colspan=2\|With Assessment !colspan=2\|Simple Planetary Gearset: Teeth{{efn\|Layout Input and output are on opposite sides Planetary gearset 1 is on the input (turbine) side Input shafts is R₁ Output shaft is C₂ (the carrier of gearset 2)}} !Count !Total{{efn\|Total Ratio Span (Total Ratio Spread · Total Gear Ratio) $\tfrac{i_n} {i_1}$ A wider span enables the downspeeding when driving outside the city limits increase the climbing ability when driving over mountain passes or off-road or when towing a trailer}} Center{{efn\|Ratio Span's Center $(i_n i_1)^\tfrac{1} {2}$ The center indicates the speed level of the transmission Together with the final drive ratio it gives the shaft speed level of the vehicle}} !Avg.{{efn\|Average Gear Step $(\tfrac{i_n} {i_1})^\tfrac{1} {n-1}$ With decreasing step width the gears connect better to each other shifting comfort increases}}
colspan=7 style="background:#AAF;"\|
Model Type !Version First Delivery !S₁{{efn\|Sun 1: sun gear of gearset 1}} R₁{{efn\|Ring 1: ring gear of gearset 1}} !S₂{{efn\|Sun 2: sun gear of gearset 2}} R₂{{efn\|Ring 2: ring gear of gearset 2}} !Brakes Clutches !Ratio Span !Gear Step{{efn\|name=50:50\|Standard 50:50 — 50 % Is Above And 50 % Is Below The Average Gear Step — With steadily decreasing gear steps (yellow highlighted line Step) and a particularly large step from 1st to 2nd gear the lower half of the gear steps (between the small gears; rounded down, here the first 1) is always larger and the upper half of the gear steps (between the large gears; rounded up, here the last 1) is always smaller than the average gear step (cell highlighted yellow two rows above on the far right) lower half: {{font color\|red\|smaller gear steps are a waste of possible ratios (red bold)}} upper half: {{font color\|red\|larger gear steps are unsatisfactory (red bold)}}}}
style="font-style:italic;" !Gear Ratio ! !R ${i_R}$ ! !1 ${i_1}$ !2 ${i_2}$ !3 ${i_3}$
Step{{efn\|name=50:50}} ! ! $-\tfrac{i_R} {i_1}$ {{efn\|name=R:1\|Standard R:1 — Reverse And 1st Gear Have The Same Ratio — The ideal reverse gear has the same transmission ratio as 1st gear no impairment when maneuvering especially when towing a trailer a torque converter can only partially compensate for this deficiency Plus 11.11 % minus 10 % compared to 1st gear is good {{font color\|red\|Plus 25 % minus 20 % is acceptable (red)}} {{font color\|red\|Above this is unsatisfactory (bold)}}}} ! ! $\tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_2}$ {{efn\|name=1:2\|Standard 1:2 — Gear Step 1st To 2nd Gear As Small As Possible — With continuously decreasing gear steps (yellow marked line Step) the largest gear step is the one from 1st to 2nd gear, which for a good speed connection and a smooth gear shift must be as small as possible A gear ratio of up to 1.6667:1 (5:3) is good {{font color\|red\|Up to 1.7500:1 (7:4) is acceptable (red)}} {{font color\|red\|Above is unsatisfactory (bold)}}}} ! $\tfrac{i_2} {i_3}$
Δ Step{{efn\|name=LS\|From large to small gears (from right to left)}}{{efn\|name=step\|Standard STEP — From Large To Small Gears: Steady And Progressive Increase In Gear Steps — Gear steps should increase: Δ Step (first green highlighted line Δ Step) is always greater than 1 As progressive as possible: Δ Step is always greater than the previous step {{font color\|red\|Not progressively increasing is acceptable (red)}} {{font color\|red\|Not increasing is unsatisfactory (bold)}}}} !style="background:#DDF;"\| !style="background:#DDF;"\| !style="background:#DDF;"\| !style="background:#DDF;"\| ! $\tfrac{i_1} {i_2} : \tfrac{i_2} {i_3}$ !style="background:#DDF;"\|
Shaft Speed ! ! $\tfrac{i_1} {i_R}$ ! ! $\tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_2}$ ! $\tfrac{i_1} {i_3}$
Δ Shaft Speed{{efn\|name=speed\|Standard SPEED — From Small To Large Gears: Steady Increase In Shaft Speed Difference — Shaft speed differences should increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one {{font color\|red\|1 difference smaller than the previous one is acceptable (red)}} {{font color\|red\|2 consecutive ones are a waste of possible ratios (bold)}}}} ! ! $0 - \tfrac{i_1} {i_R}$ ! ! $\tfrac{i_1} {i_1} - 0$ ! $\tfrac{i_1} {i_2} - \tfrac{i_1} {i_1}$ ! $\tfrac{i_1} {i_3} - \tfrac{i_1} {i_2}$
colspan=7 style="background:#AAF;"\|
W4A 040 722.0 \|{{convert\|40\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1971Hans Joachim Foerster · Automatische Fahrzeuggetriebe · p. 452 · Berlin and Heidelberg 1991 · Print {{ISBN\|978-3-642-84119-4}} · Online {{ISBN\|978-3-642-84118-7}} \|44 76 \|35 76 \|3 2 \|{{round\|1665/7221/1\|4}} {{round\|(1665/7221/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{round\|(1665/722*1/1)^(1/2)\|4}}{{efn\|name=50:50}}
style="font-style:italic;" !Gear Ratio \| \|{{font color\|red\|{{round
1221/665\|4}}{{efn\|name=R:1}} $-\tfrac{1,221}{665}$ }} \| \|{{round\|1665/722\|4}} $\tfrac{1,665}{722}$ \|{{round\|111/76\|4}} $\tfrac{63}{25}$ \|1.0000 $\tfrac{1}{1}$
Step \| \|{{font color\|red\|0.7962}}{{efn\|name=R:1}} \| !1.0000 \|style="background:#FFC;"\|1.5789 \|style="background:#FFC;"\|1.4605
Δ Step{{efn\|name=LS}} \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DDF;"\| \|style="background:#DFD;"\|1.0811 \|style="background:#DDF;"\|
Speed \| \|{{font color\|red\|-1.2560}} \| !1.0000 \|1.5789 \|2.3061
Δ Speed \| \|{{font color\|red\|1.2560}} \| !1.0000 \|style="background:#DFD;"\|0.5789 \|style="background:#DFD;"\|0.9411
colspan=7\|
W4A 050 722.0 \|{{convert\|50\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1973 \|44 76 \|35 76 \|3 2 \|{{round\|1665/7221/1\|4}} {{round\|(1665/7221/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{round\|(1665/722*1/1)^(1/2)\|4}}{{efn\|name=50:50}}
style="font-style:italic;" !Ratio \| \|{{font color\|red\|{{round
1221/665\|4}}{{efn\|name=R:1}}}} \| \|{{round\|1665/722\|4}} \|{{round\|111/76\|4}} \|1.0000
colspan=7\|
W4A 050 reinf. 722.0 \|{{convert\|56\|kpm\|lbft\|0\|abbr=on\|lk=on}} 1975 \|44 76 \|35 76 \|3 2 \|{{round\|1665/7221/1\|4}} {{round\|(1665/7221/1)^(1/2)\|4}} \|style="background:#FFC;"\|{{round\|(1665/722*1/1)^(1/2)\|4}}{{efn\|name=50:50}}
style="font-style:italic;" !Ratio \| \|{{font color\|red\|{{round
1221/665\|4}}{{efn\|name=R:1}}}} \| \|{{round\|1665/722\|4}} \|{{round\|111/76\|4}} \|1.0000
colspan="7" style="background:#AAF;"\|
style="font-style:italic;" !Ratio \|colspan=2\| $-\tfrac{S_1 (S_2+ R_2)} {R_1 S_2}$ \|colspan=2\| $\tfrac{(S_1+ R_1) (S_2+ R_2)} {R_1 R_2}$ \| $\tfrac{S_2+ R_2} {R_2}$ \| $\tfrac{1} {1}$
colspan=7\|Algebra And Actuated Shift Elements
Brake A{{efn\|Blocks S₁}} \| \| \| \|❶ \| \|
Brake B{{efn\|Blocks S₂}} \| \| \| \|❶ \|❶ \|
Brake R{{efn\|Blocks C₁(the carrier of gearset 1)}} \| \|❶ \| \| \| \|
Clutch D{{efn\|Couples S₁ with C₁ (the carrier of gearset 2)}} \| \| \| \| \|❶ \|❶
Clutch E{{efn\|Couples S₁ with S₂}} \| \|❶ \| \| \| \|❶
colspan="7" style="background:#AAF;"\|
colspan="7"\| {{notelist\|2\|group=efn}}
colspan="7" style="background:#AAF;"\|

class="wikitable collapsible" style="text-align:center"

|+Gear Ratios

!colspan=2|With Assessment

!colspan=2|Simple Planetary
Gearset: Teeth{{efn|Layout

Input and output are on opposite sides
Planetary gearset 1 is on the input (turbine) side
Input shafts is R₁
Output shaft is C₂ (the carrier of gearset 2)}}

!Count

!Total{{efn|Total Ratio Span (Total Ratio Spread · Total Gear Ratio)

$\tfrac{i_n} {i_1}$
A wider span enables the
downspeeding when driving outside the city limits
increase the climbing ability
when driving over mountain passes or off-road
or when towing a trailer}}
Center{{efn|Ratio Span's Center
$(i_n i_1)^\tfrac{1} {2}$
The center indicates the speed level of the transmission
Together with the final drive ratio
it gives the shaft speed level of the vehicle}}

!Avg.{{efn|Average Gear Step

$(\tfrac{i_n} {i_1})^\tfrac{1} {n-1}$
With decreasing step width
the gears connect better to each other
shifting comfort increases}}

colspan=7 style="background:#AAF;"|

Model
Type

!Version
First Delivery

!S₁{{efn|Sun 1: sun gear of gearset 1}}
R₁{{efn|Ring 1: ring gear of gearset 1}}

!S₂{{efn|Sun 2: sun gear of gearset 2}}
R₂{{efn|Ring 2: ring gear of gearset 2}}

!Brakes
Clutches

!Ratio
Span

!Gear
Step{{efn|name=50:50|Standard 50:50
— 50 % Is Above And 50 % Is Below The Average Gear Step —

With steadily decreasing gear steps (yellow highlighted line Step)
and a particularly large step from 1st to 2nd gear
the lower half of the gear steps (between the small gears; rounded down, here the first 1) is always larger
and the upper half of the gear steps (between the large gears; rounded up, here the last 1) is always smaller
than the average gear step (cell highlighted yellow two rows above on the far right)
lower half: {{font color|red|smaller gear steps are a waste of possible ratios (red bold)}}
upper half: {{font color|red|larger gear steps are unsatisfactory (red bold)}}}}

style="font-style:italic;"

!Gear
Ratio

!R
${i_R}$

!1
${i_1}$

!2
${i_2}$

!3
${i_3}$

Step{{efn|name=50:50}}

! $-\tfrac{i_R} {i_1}$ {{efn|name=R:1|Standard R:1
— Reverse And 1st Gear Have The Same Ratio —

The ideal reverse gear has the same transmission ratio as 1st gear
no impairment when maneuvering
especially when towing a trailer
a torque converter can only partially compensate for this deficiency
Plus 11.11 % minus 10 % compared to 1st gear is good
{{font color|red|Plus 25 % minus 20 % is acceptable (red)}}
{{font color|red|Above this is unsatisfactory (bold)}}}}

! $\tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_2}$ {{efn|name=1:2|Standard 1:2
— Gear Step 1st To 2nd Gear As Small As Possible —

With continuously decreasing gear steps (yellow marked line Step)
the largest gear step is the one from 1st to 2nd gear, which
for a good speed connection and
a smooth gear shift
must be as small as possible
A gear ratio of up to 1.6667:1 (5:3) is good
{{font color|red|Up to 1.7500:1 (7:4) is acceptable (red)}}
{{font color|red|Above is unsatisfactory (bold)}}}}

! $\tfrac{i_2} {i_3}$

Δ Step{{efn|name=LS|From large to small gears (from right to left)}}{{efn|name=step|Standard STEP
— From Large To Small Gears: Steady And Progressive Increase In Gear Steps —

Gear steps should
increase: Δ Step (first green highlighted line Δ Step) is always greater than 1
As progressive as possible: Δ Step is always greater than the previous step
{{font color|red|Not progressively increasing is acceptable (red)}}
{{font color|red|Not increasing is unsatisfactory (bold)}}}}

!style="background:#DDF;"|

! $\tfrac{i_1} {i_2} : \tfrac{i_2} {i_3}$

!style="background:#DDF;"|

Shaft
Speed

! $\tfrac{i_1} {i_R}$

! $\tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_2}$

! $\tfrac{i_1} {i_3}$

Δ Shaft
Speed{{efn|name=speed|Standard SPEED
— From Small To Large Gears: Steady Increase In Shaft Speed Difference —

Shaft speed differences should
increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one
{{font color|red|1 difference smaller than the previous one is acceptable (red)}}
{{font color|red|2 consecutive ones are a waste of possible ratios (bold)}}}}

! $0 - \tfrac{i_1} {i_R}$

! $\tfrac{i_1} {i_1} - 0$

! $\tfrac{i_1} {i_2} - \tfrac{i_1} {i_1}$

! $\tfrac{i_1} {i_3} - \tfrac{i_1} {i_2}$

colspan=7 style="background:#AAF;"|

W4A 040
722.0

|{{convert|40|kpm|lbft|0|abbr=on|lk=on}}
1971Hans Joachim Foerster · Automatische Fahrzeuggetriebe · p. 452 · Berlin and Heidelberg 1991 · Print {{ISBN|978-3-642-84119-4}} · Online {{ISBN|978-3-642-84118-7}}

|44
76

|35
76

|3
2

|{{round|1665/722*1/1|4}}
{{round|(1665/722*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{round|(1665/722*1/1)^(1/2)|4}}{{efn|name=50:50}}

style="font-style:italic;"

!Gear
Ratio

|{{font color|red|{{round

1221/665|4}}{{efn|name=R:1}}

-\tfrac{1,221}{665}

}}

|{{round|1665/722|4}}
$\tfrac{1,665}{722}$

|{{round|111/76|4}}
$\tfrac{63}{25}$

|1.0000
$\tfrac{1}{1}$

Step

|{{font color|red|0.7962}}{{efn|name=R:1}}

!1.0000

|style="background:#FFC;"|1.5789

|style="background:#FFC;"|1.4605

Δ Step{{efn|name=LS}}

|style="background:#DDF;"|

|style="background:#DFD;"|1.0811

|style="background:#DDF;"|

Speed

|{{font color|red|-1.2560}}

!1.0000

|1.5789

|2.3061

Δ Speed

|{{font color|red|1.2560}}

!1.0000

|style="background:#DFD;"|0.5789

|style="background:#DFD;"|0.9411

colspan=7|

W4A 050
722.0

|{{convert|50|kpm|lbft|0|abbr=on|lk=on}}
1973

|44
76

|35
76

|3
2

|{{round|1665/722*1/1|4}}
{{round|(1665/722*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{round|(1665/722*1/1)^(1/2)|4}}{{efn|name=50:50}}

style="font-style:italic;"

!Ratio

|{{font color|red|{{round

1221/665|4}}{{efn|name=R:1}}}}

|{{round|1665/722|4}}

|{{round|111/76|4}}

|1.0000

colspan=7|

W4A 050 reinf.
722.0

|{{convert|56|kpm|lbft|0|abbr=on|lk=on}}
1975

|44
76

|35
76

|3
2

|{{round|1665/722*1/1|4}}
{{round|(1665/722*1/1)^(1/2)|4}}

|style="background:#FFC;"|{{round|(1665/722*1/1)^(1/2)|4}}{{efn|name=50:50}}

style="font-style:italic;"

!Ratio

|{{font color|red|{{round

1221/665|4}}{{efn|name=R:1}}}}

|{{round|1665/722|4}}

|{{round|111/76|4}}

|1.0000

colspan="7" style="background:#AAF;"|

style="font-style:italic;"

!Ratio

|colspan=2| $-\tfrac{S_1 (S_2+ R_2)} {R_1 S_2}$

|colspan=2| $\tfrac{(S_1+ R_1) (S_2+ R_2)} {R_1 R_2}$

| $\tfrac{S_2+ R_2} {R_2}$

| $\tfrac{1} {1}$

colspan=7|Algebra And Actuated Shift Elements

Brake A{{efn|Blocks S₁}}

|❶

Brake B{{efn|Blocks S₂}}

|❶

Brake R{{efn|Blocks C₁(the carrier of gearset 1)}}

|❶

Clutch D{{efn|Couples S₁ with C₁ (the carrier of gearset 2)}}

|❶

Clutch E{{efn|Couples S₁ with S₂}}

|❶

colspan="7" style="background:#AAF;"|

colspan="7"| {{notelist|2|group=efn}}

colspan="7" style="background:#AAF;"|

Applications

=K4A 025=

1961–1965 (saloon) · 1961–1968 (coupé/convertible) W 111
1961–1965 (saloon) · 1962–1968 (coupé/convertible) W 112
1961–1968 W 110
1963–1971 W 113
1965–1968 W 108/W 109

=K4B 050=

1963–1981 600 (W 100)
1968–1972 300 SEL 6.3 (W 109)

=K4C 025=

1968–1971 (coupé/convertible) W 111
1968–1972 W 108/W 109

class="wikitable collapsible collapsed"

|+W 114/W 115

!Chassis code

!Car model

!Engine code

!Transmission
code

114.015 and 114.615

|230.6

|rowspan="2"|180.954

|rowspan="2"|722.203

114.017 and 114.617

|230.6 Lang

114.011 and 114.611

|250

|rowspan="2"|130.923

|rowspan="2"|722.204

114.023 and 114.623

|250 C

114.060 and 114.660

|280

|rowspan="2"|110.921

|rowspan="2"|722.202

114.073 and 114.673

|280 C

114.062 and 114.662

|280 E

|rowspan="2"|110.981

|rowspan="2"|722.200

114.072 and 114.672

|280 CE

115.015 and 115.615

|200

|115.923

|rowspan="2"|722.205

115.010

|220

|115.920

115.115 and 115.715

|200 D

|615.913

|rowspan="3"|722.206

115.110 and 115.710

|220 D

|rowspan="2"|615.912

115.112

|220 D Lang

=K4A 040=

class="wikitable collapsible collapsed"

|+W 108/W 109

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

109.057

|300 SEL 3.5

|rowspan=3|3.5 L
M 116 V8

|rowspan=3|722.201

|rowspan=3|worldwide
except USA

108.067

|280 SE 3.5

108.068

|280 SEL 3.5

class="wikitable collapsible collapsed"

|+R 107/C 107

!Chassis code

!Car model

!Engine code

!Transmission
code

107.043

|350 SL

|rowspan="2"|116.982 (D-Jet)
116.984 (K-Jet)

|rowspan="2"|722.201

107.023

|350 SLC

=W3A 040=

class="wikitable collapsible collapsed"

|+W 108/W 109

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

109.056

|300 SEL 4.5

|rowspan=3|4.5 L
M 117 V8

|rowspan=3|722.000

|rowspan=3|USA only

108.057

|280 SE 4.5

108.058

|280 SEL 4.5

class="wikitable collapsible collapsed"

|+R 107/C 107

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

107.043

|350 SL

|rowspan="2"|116.982 (D-Jet)
116.984 (K-Jet)

|rowspan="2"|722.002

107.023

|350 SLC

107.044

|450 SL

|rowspan="2"|117.982 (D-Jet)
117.985 (K-Jet)

|rowspan="2"|722.004

|rowspan="2"|USA and
Japan only

107.024

|450 SLC

class="wikitable collapsible collapsed" \|+W 116
Chassis code !Car model !Engine code !Transmission code !Notes
116.028 \|350 SE \|rowspan="2"\|116.983 (D-Jet) 116.985 (K-Jet) \|rowspan="2"\|722.002
116.029 \|350 SEL
116.032 \|450 SE \|rowspan="2"\|117.983 (D-Jet) 117.986 (K-Jet) \|rowspan="2"\|722.004 \|rowspan="2"\|USA and Japan only
116.033 \|450 SEL

class="wikitable collapsible collapsed"

|+W 116

Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

116.028

|350 SE

|rowspan="2"|116.983 (D-Jet)
116.985 (K-Jet)

|rowspan="2"|722.002

116.029

|350 SEL

116.032

|450 SE

|rowspan="2"|117.983 (D-Jet)
117.986 (K-Jet)

|rowspan="2"|722.004

|rowspan="2"|USA and
Japan only

116.033

|450 SEL

=W3B 050=

class="wikitable collapsible collapsed"

|+R 107/C 107

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

107.044

|450 SL

|rowspan="2"|117.982 (D-Jet)
117.985 (K-Jet)

|rowspan="2"|722.001

|rowspan="2"|worldwide except
USA and Japan

107.024

|450 SLC

class="wikitable collapsible collapsed"

|+W 116

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

116.032

|450 SE

|rowspan="2"|117.983 (D-Jet)
117.986 (K-Jet)

|rowspan="2"|722.001

|rowspan="2"|worldwide except
USA and Japan

116.033

|450 SEL

116.036

|450 SEL 6.9

|100.985

|722.003

|722.003
W3B 050 reinforced{{cite web|title=MB AUS 1979, PDF p. 57|url=http://img.w116.org/tech/AUS_1979.pdf}}

=W4B 025=

class="wikitable collapsible collapsed"

|+R 107/C 107

!Chassis code

!Car model

!Engine code

!Transmission
code

107.042

|280 SL

|110.982
110.986
110.990

|rowspan="2"|722.103
722.112

107.022

|280 SLC

|110.982
110.986

class="wikitable collapsible collapsed"

|+W 114/W 115

!Chassis code

!Car model

!Engine code

!Transmission
code

114.015 and 114.615

|230.6

|rowspan="2"|180.954

|rowspan="2"|722.105

114.017 and 114.617

|230.6 Lang

114.011 and 114.611

|250

|rowspan="2"|130.923

|rowspan="2"|722.104

114.023 and 114.623

|250 C

114.060 and 114.660

|280

|rowspan="2"|110.921

|rowspan="2"|722.102

114.073 and 114.673

|280 C

114.062 and 114.662

|280 E

|rowspan="2"|110.981

|rowspan="2"|722.103

114.072 and 114.672

|280 CE

115.015 and 115.615

|200

|115.923

|722.106

115.017

|230.4

|115.951

|722.110

115.115 and 115.715

|200 D

|615.913

|rowspan="3"|722.107

115.110 and 115.710

|220 D

|rowspan="2"|615.912

115.112

|220 D Lang

115.117

|240 D

|rowspan="2"|616.916

|rowspan="2"|722.108

115.119

|240 D Lang

115.114

|240 D 3.0

|617.910

|722.109

class="wikitable collapsible collapsed"

|+W 116

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

116.020

|280 S

|110.922

|722.100
722.102
722.111

116.024

|280 SE

|rowspan="2"|110.983 (D-Jet)
110.985 (K-Jet)

|rowspan="2"|722.101
722.103
722.112

116.025

|280 SEL

116.120

|300 SD

|617.950

|722.120

|USA only

class="wikitable collapsible collapsed"

|+W 123

!Chassis code

!Car model

!Engine code

!Transmission
code

!Notes

123.020

|200

|115.938
115.939

|722.115

123.220

|200

|rowspan="2"|102.920
102.939

|rowspan="2"|722.121

123.280

|200 T

123.023

|230

|rowspan="3"|115.954

|rowspan="3"|722.119

123.083

|230 T

123.043

|230 C

123.223

|230 E

|rowspan="3"|102.980

|rowspan="3"|722.122

123.283

|230 TE

123.243

|230 CE

123.026

|250

|rowspan="3"|123.920
123.921

|rowspan="3"|722.113

123.086

|250 T

123.028

|250 Lang

123.030

|280

|rowspan="2"|110.923

|rowspan="2"|722.111

123.050

|280 C

123.033

|280 E

|rowspan="3"|110.984
110.988

|rowspan="3"|722.112

123.093

|280 TE

123.053

|280 CE

123.120

|200 D

|615.940

|rowspan="2"|722.116

123.126

|220 D

|615.941

123.123

|240 D

|rowspan="3"|616.912

|rowspan="3"|722.117

123.183

|240 TD

123.125

|240 D Lang

123.130

|300 D

|rowspan="4"|617.912

|rowspan="4"|722.118

123.190

|300 TD

123.132

|300 D Lang

123.150

|300 CD

|USA only

Mercedes-Benz first series automatic transmission

1961: K4A 025<br>— 4-Speed Transmission With 2 Planetary Gearsets —

= Layout =

= Specifications =

1964: K4B 050 And Follow-Up Products<br>— 4-Speed Transmissions With 3 Planetary Gearsets —

= Layout =

= Models =

== 1964: K4B 050 ==

== 1967: K4C 025 ==

== 1972: W4B 025 ==

== Variants For Commercial Cars ==

=Specifications=

1971: W3A 040 And Follow-Up Products<br>— 3-Speed Transmissions With 2 Planetary Gearsets —

=Layout=

=Specifications=

Applications

=K4A 025=

=K4B 050=

=K4C 025=

=K4A 040=

=W3A 040=

=W3B 050=

=W4B 025=

See also

References

Mercedes-Benz first series automatic transmission

1961: K4A 025<br>&mdash; 4-Speed Transmission With 2 Planetary Gearsets&nbsp;&mdash;

= Layout =

= Specifications =

1964: K4B 050 And Follow-Up Products<br>&mdash; 4-Speed Transmissions With 3 Planetary Gearsets&nbsp;&mdash;

= Layout =

= Models =

== 1964: K4B&nbsp;050 ==

== 1967: K4C&nbsp;025 ==

== 1972: W4B&nbsp;025 ==

== Variants For Commercial Cars ==

=Specifications=

1971: W3A 040 And Follow-Up Products<br>&mdash; 3-Speed Transmissions With 2 Planetary Gearsets&nbsp;&mdash;

=Layout=

=Specifications=

Applications

=K4A 025=

=K4B&nbsp;050=

=K4C&nbsp;025=

=K4A&nbsp;040=

=W3A&nbsp;040=

=W3B&nbsp;050=

=W4B&nbsp;025=

See also

References

1961: K4A 025<br>— 4-Speed Transmission With 2 Planetary Gearsets —

1964: K4B 050 And Follow-Up Products<br>— 4-Speed Transmissions With 3 Planetary Gearsets —

== 1964: K4B 050 ==

== 1967: K4C 025 ==

== 1972: W4B 025 ==

1971: W3A 040 And Follow-Up Products<br>— 3-Speed Transmissions With 2 Planetary Gearsets —

=K4B 050=

=K4C 025=

=K4A 040=

=W3A 040=

=W3B 050=

=W4B 025=