Overhaul - 42LE Automatic Transmission: Description

The 42LE is a electronically controlled 4-speed transaxle. Transaxle uses hydraulically operated clutches controlled by the Transaxle Control Module (TCM). Transaxle consists of 3 multiple-disc input clutches, 2 multiple-disc holding clutches, 4 hydraulic accumulators and 2 planetary gear sets to provide 4 forward speeds and reverse. See Figure.

The TCM receives information from various sensors and in turn controls the solenoid assembly through the transaxle control relay. Solenoid assembly consists of 4 solenoids for controlling hydraulic pressure to 4 of the 5 transaxle clutches.

The TCM contains an adaptive memory which learns application and release rates of transaxle components for smooth operation. The TCM also learns the rate at which applied elements build pressure sufficient for a speed change. Adaptive control can adapt to altitude, temperature, engine output, etc.