Contents: Table. Technical characteristics of…⤓ Planetary gearbox ⤓ Hydraulic control system ⤓ Electronic control system ⤓
Attention:
- - The gearbox type is indicated on the model identification plate located on the inside of the hood in the "TRANS / AXLE" line.
- - For procedures for checking the level and replacing the working fluid in the automatic transmission, see the chapter "Maintenance and general check and adjustment procedures".
Table. Technical characteristics of automatic transmission F4A42.
| Parameter | Technical specifications |
| Gearbox type | 4-speed with 1 reverse gear, fully automatic with electronic control |
| Gear ratio of the gearbox | |
| 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 clutch, 2 - overdrive planetary gear set, 3 - second gear brake, 4 - first gear and reverse gear brake, 5 - main planetary gear set, 6 - gearbox housing, 7 - intermediate gear pinion, 8 - underdrive clutch, 9 - torque converter, 10 - torque converter lock-up clutch, 11 - input shaft, 12 - automatic transmission working fluid pump, 13 - torque converter housing, 14 - front interwheel differential, 15 - intermediate gear driven pinion, 16 - intermediate gear pinion 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 locking clutches and two disc brakes.
Power from the engine is transmitted through the torque converter to the input shaft of the planetary gearbox.
Gear shifting is accomplished by engaging a specific combination of two F4A42 controls, which changes the output shaft speed.
Hydraulic control system
The hydraulic control system includes a working fluid pump, an automatic transmission working fluid cooler (built into the cooling system radiator), a control valve block, hydraulic accumulators, clutches and brakes.
The main pressure in the system is created by the pump, it is regulated depending on the load and speed of the car and ensures the operation of the torque converter, clutches and brakes. The switching valves in the valve block control the flow of working fluid that enters 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 on the gearbox (pulse generators, automatic transmission fluid temperature sensor, vehicle speed sensor, etc.), control switches, an electronic automatic transmission control unit, electromagnetic valves for controlling the flow of working fluid in the hydraulic system (located on the control valve block).