Chrysler laser 1990 Technical Information Manual page 307

AUTOMATIC TRANSAXLE - Transaxle Control
From rear
clutch
shift valve
From N-D
control valve
From
To manual
shift
valve
control
valve
C h e c k t
To shift
From N-D
control To manual
valve
valve
valve
pressure)
Upshift from 3rd to 4th
directed to the rear clutch exhaust valve through the No.8
line, it pushes the elements "A" and "B" of the rear clutch
exhaust valve to the right.
(2) The element "B" of the rear clutch exhaust valve that has
been moved towards the right closes the No.5~ line port.
This prevents the line pressure coming from the N-D
control valve from being directed to the rear clutch.
(3) The line pressure supplied to the rear clutch is discharged
from the No. 15 line through the No.20 and No.20a lines.
This releases the rear clutch.
Downshift from 4th to 3rd
(1) If the 4th pressure from the shift control valve is dis-
charged, the element "A" of the rear clutch exhaust valve
is pushed to the left under the line pressure established in
the No.5~ line. This line pressure is directed to the rear
clutch via the No.20 line, No. 20a line, and then No. 15 line.
In one of the passages connecting the No.20 line with the
No. 20a line, there is a check ball and in the other there is an
orifice. When one passage is closed by the check ball, the
fluid flows through the other passage with an orifice, which
slows down the fluid flow speed, permitting gradual
transaxle of pressure to the No.20a line to create condi-
tions ready for the rear clutch to operate.
(2) When the 2-3/4-3 shift valve operates and the hydraulic
pressure acts on the front clutch and the release side
chamber of kickdown servo cylinder, the pressure is
directed through the No. 12 line to the right end of the
element "8" of the clutch exhaust valve.
Combined with the spring force, this pressure pushes the
element "B" of the valve to the left. This allows the high
line pressure in the No.5~ line to be directly transmitted to
the rear clutch through the No. 15 line.
Gear
Gear
21-85