Engineering:Mercedes-Benz 4G-Tronic transmission: Difference between revisions
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Latest revision as of 02:49, 13 April 2022
| Mercedes-Benz W4A 028 · W4A 040 · W4A 020 · W5A 030 | |
|---|---|
| Overview | |
| Manufacturer | Daimler AG |
| Production | 1979–1996 |
| Body and chassis | |
| Class | 4-speed longitudinal automatic transmission |
| Chronology | |
| Predecessor | Mercedes-Benz first series automatic transmission |
| Successor | 5G-Tronic (Type 722.6) |
The Mercedes-Benz 4G-Tronic transmission was produced from 1979 to 1996 in W4A 028, W4A 040 (both type 722.3), W4A 020 (type 722.4), and W5A 030 (type 722.5) variants.
Abstract
The 4G-Tronic transmission is a hydraulically operated four speed automatic without lock-up that replaced the similarly designed W3A 040, W3B 050, and W4B 025 family of automatic transmission in 1979. It is calibrated to take off in second gear to reduce "creeping" and provide a smoother ride. The transmission will select 1st only if the selector is in "2" or in case of abrupt acceleration. Other attributes of this transmission include a 2-3 shift delay when the engine is cold in order to speed up catalyst warm-up. 4th gear is a 1:1 ratio.
The W4A 040 and the W4A 020 were used until mid-1996. The W4A 028 variant was used for off-road applications (RWD and 4X4). The W5A 030 is basically the same transmission with an additional electrically controlled 5th gear overdrive section attached to the main body in a separate housing; it was available as an extra charge option. All 4G-Tronics were succeeded by the more modern and economic 5G-Tronic (Type 722.6) transmission that features an integrated 5th gear overdrive ratio, torque converter lock-up and fully electronic control.
It is considered by enthusiasts to be one of the most reliable transmissions ever built by Mercedes-Benz with some examples exceeding 300,000 miles of service.
Specifications
Basic concept
For this W4A-models 4 forward gears[lower-alpha 1] using 8 main components[lower-alpha 2][1] show economic equivalence with the direct predecessor.[lower-alpha 3] 5 forward gears[lower-alpha 4] out of 11 main components[lower-alpha 5][1] and the need of two housings[lower-alpha 6] and two different controls[lower-alpha 7] turn out the W5A 030 as the least economically designed automatic transmission ever manufactured for passenger cars. Obviously a transition solution: the direct successor, launched in 1996, requires 9 main components,[lower-alpha 8] one housing and one control.[lower-alpha 9]
Gear ratios
| Gear Teeth and Ratios | Planetary Gearset: Teeth | Count | Total | Avg. | ||||
|---|---|---|---|---|---|---|---|---|
| Ravigneaux | Simple | |||||||
| Model
Type |
Version
First Delivery |
Sun 1.1
Ring 1.1 |
Sun 1.2
Ring 1.2 |
Sun 2
Ring 2 |
Sun 3
Ring 3 |
Brakes
Clutches |
Ratio
Span |
Gear
Step |
| Gear | 1 | 2 | 3 | 4 | 5 | R | ||
| W4A 040
722.3 |
392 Nm · 289 lb·ft
1979[1] |
34
50 |
50
78 |
34
78 |
3
2 |
3.6759 | 1.5433 | |
| Ratio | 3.6759 | 2.4123 | 1.4359 | 1.0000 | - 5.1388 | |||
| W4A 020
722.4 |
196 Nm · 145 lb·ft
1982[1] |
26
42 |
42
78 |
38
78 |
3
2 |
4.2491 | 1.6197 | |
| Ratio | 4.2491 | 2.4078 | 1.4872 | 1.0000 | - 5.6692 | |||
| W4A 040 II
722.3 |
392 Nm · 289 lb·ft
1985[1] |
26
46 |
46
78 |
34
78 |
3
2 |
3.8707 | 1.5701 | |
| Ratio | 3.8707 | 2.2475 | 1.4359 | 1.0000 | - 5.5857 | |||
| W4A 028
722.3[2] |
274 Nm · 202 lb·ft
1990 |
26
46 |
46
78 |
34
78 |
3
2 |
3.8707 | 1.5701 | |
| Ratio | 3.8707 | 2.2475 | 1.4359 | 1.0000 | - 5.5857 | |||
| W5A 030
722.5 |
294 Nm · 217 lb·ft
1990[1] |
26
46 |
46
78 |
34
78 |
26
78 |
4
3 |
5.1609 | 1.5072 |
| Ratio | 3.8707 | 2.2475 | 1.4359 | 1.0000 | 0.7500 | - 5.5857 | ||
Applications
The 4G-Tronic has been used in many Mercedes-Benz cars.
W4A 028 (Type 722.3)
- 1990-1995 G-Class 463
W4A 040 I+II (Type 722.3)
- 1981-1989 R107 and C107
- 1989-1996 R129
| 1981-1985 W123 | ||||
|---|---|---|---|---|
| Chassis code | Car model | Engine code | Transmission code | Notes |
| 123.026 | 250 | 123.920, 123.921 | 722.308 | |
| 123.086 | 250T | |||
| 123.028 | 250 Lang | |||
| 123.033 | 280E | 110.984, 110.988 | 722.300, 722.309 | |
| 123.093 | 280TE | 722.309 | ||
| 123.053 | 280CE | 722.300, 722.309 | ||
| 123.133 | 300D Turbo | 617.952 | 722.315 | Only for USA 1982-1985 |
| 123.153 | 300CD Turbo | |||
| 123.193 | 300TD Turbo | 722.303 (81-85), 722.315 (82-85) | Only for USA 1981-1985 | |
W4A 020 (Type 722.4)
| 1982-1985 W123 | ||||
|---|---|---|---|---|
| Chassis code | Car model | Engine code | Transmission code | Notes |
| 123.220 | 200 | 102.920, 102.939 | 722.406 | |
| 123.280 | 200T | |||
| 123.223 | 230E | 102.980 | 722.401 | |
| 123.283 | 230TE | |||
| 123.243 | 230CE | |||
| 123.120 | 200D | 615.940 | 722.407 | |
| 123.123 | 240D | 616.912 | 722.404 | |
| 123.183 | 240TD | |||
| 123.125 | 240D Lang | |||
| 123.130 | 300D | 617.912 | 722.405 | |
| 123.190 | 300TD | |||
| 123.132 | 300D Lang | |||
| 123.133 | 300D Turbo | 617.952 | 722.416 | Only for California 1985 |
| 123.153 | 300CD Turbo | |||
| 123.193 | 300TD Turbo | |||
W5A 030 (Type 722.5)
See also
Notes
- ↑ plus 1 reverse gear
- ↑ 3 planetary gearsets (Ravigneaux planetary gearset considered as 2), 3 brakes, 2 clutches
- ↑ 3 simple planetary gearsets, 3 brakes, 2 clutches
- ↑ plus 1 reverse gear
- ↑ 4 planetary gearsets (Ravigneaux planetary gearset considered as 2), 4 brakes, 3 clutches
- ↑ regular bousing for gear 1 to 4 and reverse gear · supplemental housing for gear 5
- ↑ hydraulic for gear 1 to 4 and reverse gear · electronic for gear 5
- ↑ 3 simple planetary gearsets, 3 brakes, 3 clutches
- ↑ electronic
References
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