Automatic Transaxle Overhaul & Testing - 4T40-E: Description

Hydra-Matic 4T40-E transaxle is a fully automatic 4-speed transaxle consisting primarily of a 3-element hydraulic torque converter and converter clutch. Transaxle uses a variable capacity vane-type oil pump to supply all hydraulic pressure needed for operation.

Multiplied torque from torque converter is transferred to transaxle by a sprocket and drive link assembly. Other internal components consist of 5 multiple-disc clutches, 3 one-way clutches, 2 roller clutches, a sprag clutch, 2 bands and 2 planetary (carrier) gear sets. Differential and final drive assemblies are an integral part of transaxle. See Figure .

The 4T40-E uses 2 electronic shift solenoids, controlled by Powertrain Control Module (PCM), to switch hydraulic pressure on or off. Torque Converter Clutch (TCC) solenoid is a Pulse Width Modulated (PWM) solenoid which controls TCC apply and release.