Attention:
- - The gearbox type is indicated on the model identification plate located on the inside of the hood in the line "TRANS / AXLE".
- - For procedures for checking the level and replacing the working fluid in automatic transmission, see chapter "Maintenance and general inspection and adjustment procedures".
Table. Technical characteristics of automatic transmission F4A42.
Parameter | Specifications |
Gearbox type | 4-speed with 1 reverse gear, fully automatic with electronic control |
Gearbox ratio | |
1st gear | 2,842 |
2nd gear | 1,529 |
3rd gear | 1,000 |
4th gear | 0,712 |
Reverse gear | 2,480 |
Automatic transmission diagram F4A42. 1 - reverse gear clutch, 2 - increasing planetary gear set, 3 - second gear brake, 4 - first gear and reverse gear brake, 5 - main planetary gear set, 6 - gearbox housing, 7 - intermediate drive gear, 8 - underdrive clutch, 9 - torque converter, 10 - torque converter lock-up clutch, 11 - input shaft, 12 - automatic transmission fluid pump, 13 - torque converter housing, 14 - front axle differential, 15 - intermediate drive gear, 16 - intermediate gear shaft (gearbox output shaft), 17 - rear cover, 18 - overdrive clutch.
Planetary gearbox
For the F4A4 family, the planetary gearbox contains two planetary gear sets, three lockup clutches and two disc brakes.
Power from the engine through the torque converter is transmitted to the input shaft of the planetary gearbox.
Gear shifting is carried out by engaging a certain combination of two F4A42 controls, as a result of which the speed of the output shaft changes.
Hydraulic control system
The hydraulic control system includes a working fluid pump, an automatic transmission fluid cooler (built into the cooling system radiator), control valve block, hydraulic accumulators, clutches and brakes.
The main pressure in the system is created by a pump, it is regulated depending on the load and vehicle speed and ensures the operation of the torque converter, clutches and brakes. The shift valves in the valve block control the fluid flow to the torque converter and planetary gearbox.
Electronic control system
The electronic control system includes sensors of external electronic systems (throttle position sensor, coolant temperature sensor, etc.), various sensors at the checkpoint (pulse generators, automatic transmission fluid temperature sensor, vehicle speed sensor, etc.), control switches, automatic transmission electronic control unit, solenoid valves for controlling the flow of working fluid in the hydraulic system (located on the control valve block).