Chrysler laser 1990 Technical Information Manual page 261

AUTOMATIC TRANSAXLE - Transaxle Mechanism
'EAR (Overdrive)
Long pinion
End clutch
Reverse sun gear
When the shift is in 4th gear, the end clutch and the kickdown brake
are actuated, and driving force is transmitted from the input shaft
through to the planetary gear set to drive the annulus gear (the output
flange) via the long pinion.
1
Since the reverse sun gear is fastened at this time, the long pinion
The annulus gear rotates more (Or faster) than in the case of 3rd gear
in proportion to the rotation of the long pinion. The gear ratio of
overdrive is achieved in this way.