General Description

THM F-7 - Electronic Automatic Transmission:

Computer Control Inputs And Outputs.:

Shift Control Mode Chart.:

TRANSAXLE GENERAL DESCRIPTION


The THM F7 is a fully automatic front wheel drive transaxle. It provides four forward ranges (including overdrive) and one reverse range.


The THM F7 is electronically controlled by the Powertrain Control Module (PCM). Inputs to the PCM determine the shift pattern for third and fourth gears and Viscous Converter Clutch (VCC) operation. Refer to Figure.


Three solenoids in the transaxle respond to the PCM signals. Two solenoids control 2-3 and 3-4 shifts. The VCC solenoid controls the apply and release of the VCC. Figure 2 shows solenoid operation for the four gear ranges and VCC apply.


There are no trouble codes for the shift solenoids. PCM Code E039 indicates a VCC fault.





COMPONENTS

The THM F-7 is a fully automatic front wheel drive transaxle. It provides four forward ranges including overdrive.

The major components of this unit are:

^ Torque converter with viscous converter clutch.

^ 2-3 and 3-4 shift solenoids.

^ Sprocket and drive link assembly.

^ 1-2 and reverse band assemblies.

^ Input, 3rd, 2nd, and 4th clutches - multiple disc assemblies.

^ Input sprag and 3rd roller clutch.

^ Compound planetary gear set.

^ Differential and final drive assembly. Oil pressure is supplied by a variable vane type oil pump. The oil pressure is regulated by vacuum modulation and shift points are controlled by throttle opening via a throttle valve cable, governor circuit and PCM controls.