Automatic Transmission/Transaxle: Description and Operation

The A131L is a fully automatic transaxle for front wheel drive vehicles which provides three forward gear ranges and a reverse. The major components of this transaxle are:
- Torque converter
- Gear-type fluid pump
- Intermediate band and servo
- Three multiple-disc clutches
- One-way clutch
- Valve body assembly
- Governor assembly

Transaxle fluid pressure and shift points are by the governor assembly and the kickdown valve. The governor assembly is geared directly to the drive pinion inside the transaxle and controls governor fluid pressure in direct proportion to transaxle output speed. Downshifts are controlled by the kickdown valve which is located in the valve body assembly. The kickdown valve is controlled by means of a Throttle Valve (TV) cable which is connected to the accelerator pedal linkage. When the accelerator pedal is fully pressed, the TV cable pulls on the kickdown valve allowing line pressure to pass through the kickdown valve to the appropriate shift valve producing a downshift.

The A131L 3-speed automatic transaxle can be operated in any one of six different ranges:
P - Park position prevents the vehicle from rolling either forward or backward. For reasons of safety, the parking brake should be used in addition to the park position at all times.
R - Reverse position allows the vehicle to be operated in a rearward direction.
N - Neutral position allows the engine to be started and operated without driving the vehicle. If necessary, this position may be selected if the engine must be restarted with the vehicle moving.
D - Drive position is used for all normal driving conditions. It provides three gear ratios with available downshifts for safe passing by pressing the accelerator brake.
2 - Manual second is used to provide acceleration and engine braking. This range should be selected only when vehicle speed is below 48 km/h (30 mph).
L - Manual low is used to provide maximum engine braking. This range should be selected only when vehicle speed is below 24 km/h (15 mph).