Torque Converter; Case - Mitsubishi Eclipse Technical Information Manual

POWER TRAIN
Turbine
Solenoid

TORQUE CONVERTER

Torque converter clutch operation is controlled by the TCM
through the solenoid assembly and valve body as mentioned.
The clutch lining material is not bonded to either the piston
or the torque converter cover in the F4ACl transaxle, it is
free floating.
When the clutch is not engaged, pressure is directed through
the center of the input shaft to the front side of the piston.
This pressure pushes the piston rearward and allows oil to
flow around the outer edge of the piston. The oil exits the
torque converter between the input shaft and the reaction shaft.
When the torque converter clutch engages, the pressure that
was directed to the front side of the piston through the input
shaft is shut off and the circuit is vented. The pressure on
the back side of the piston pushes the piston forward and
connects the turbine to the converter housing. The piston has
no outer seal. The friction disc provides the seal between the
piston and the housing. As mentioned the friction disc is free-
floating and is not bonded to either the piston or the housing.
When the torque converter clutch is engaged, fuel economy
is improved, engine noise is reduced, and the transaxle and
fluid operating temperature is lowered.

CASE

The F4ACl transaxle uses an aluminum cast case with a
stamped steel oil pan. The transfer gears on the end of the
transaxle and differential assembly towards the back of the
transaxle are under stamped steel covers. This transaxle is
a single sump design. That is it uses only one fluid for both
the transmission and differential areas. The transaxle case
is vented through the top of the manual shaft.