| Mercedes-Benz K4A 025
K4B 050 · K4C 025 · K4A 040 W3A 040 · W3B 050 · W4B 025 W4A 018 · W4B 035 | |
|---|---|
| Overview | |
| Manufacturer | Daimler AG |
| Production | 1961–1983 |
| Body and chassis | |
| Class | 3 and 4-speed longitudinal automatic transmission |
| Chronology | |
| Successor | 4G-Tronic |
The Mercedes-Benz first series of automatic transmission was produced from 1961 to 1983 in four- and three-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.[1] 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 BorgWarner.
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 sixteen bolts.
Gear Model
|
R | 1 | 2 | 3 | 4 | Total Span |
Span Center |
Avg. Step |
Compo- nents | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| K4A 025 · 1961 | −4.145 | 3.979 | 2.520 | 1.579 | 1.000 | 3.979 | 1.995 | 1.585 | 2 Gearsets 3 Brakes 3 Clutches | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| K4B 050 · 1964 | −4.145 | 3.979 | 2.459 | 1.579 | 1.000 | 3.979 | 1.995 | 1.585 | 3 Gearsets 3 Brakes 2 Clutches | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| K4C 025 · 1967 K4A 040 · 1969 W4B 025 · 1972 |
−5.478 | 3.983 | 2.386 | 1.461 | 1.000 | 3.983 | 1.996 | 1.585 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| W4A 018 · 1975 | −5.499 | 4.006 | 2.391 | 1.463 | 1.000 | 4.006 | 2.001 | 1.588 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| W4B 035 · 1975 | −5.881 | 4.176 | 2.412 | 1.462 | 1.000 | 4.176 | 2.043 | 1.610 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| W3A 040 · 1971 W3A 050 · 1973 W3A 050 reinf. · 1975 |
−1.836 | 2.306 | 1.461 | 1.000 | 2.306 | 1.519 | 1.519 | 2 Gearsets 3 Brakes 2 Clutches | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||