DESCRIPTION & OPERATION
Hydra-Matic 4T80-E transaxle is a fully automatic 4-speed unit utilizing a 3-element hydraulic torque converter and converter clutch.
Transaxle uses 3 gear-type pumps to supply hydraulic pressure needed for operation. A scavenge pump removes oil from lower oil pan. This oil is pumped into side oil pan. A primary oil pump takes oil from side oil pan to use for line pressure oil. A secondary oil pump takes additional oil from side oil pan to use for initial clutch apply, forced downshifts, wide open throttle and reverse gear operations.
Multiplied torque from torque converter is transferred to transaxle by a sprocket and drive link assembly. Other internal components consist of 4 multiple disc clutches, a roller clutch, 2 sprag clutches, 2 bands and 2 planetary gear sets. Final drive and differential assemblies are bolted on end of transaxle.
Transaxle electronic control system consists of 2 PCM-controlled shift solenoids, pressure control solenoid (force motor), fluid temperature sensor, pressure switch assembly, 2 speed sensors, (VSS and ISS) and a TCC lock-up control solenoid.
Note. Pressure switch assembly may also be referred to as Transaxle Fluid Pressure (TFP) sensor.