Pontiac FIREBIRD 1972 Service Manual page 910

7E-20 1972 PONTIAC SERVICE MANUAL
REV. OR LO
Fig. 7E-18 Drive and Super Range
-
First Gear
is directed to the rear servo accumulator piston in prepa-
ration for the 1-2 shift (Fig. 7E-18).
DRIVE AND SUPER RANGE-SECOND
GEAR
Intermediate clutch apply oil is directed to the rear servo
accumulator piston, stroking the piston against 1-2 ac-
cumulator oil and the accumulator spring (Fig. 7E-19).
This action absorbs some intermediate clutch apply oil
and permits the intermediate clutch to apply at reduced
pressure for a smooth 1-2 shift.
REAR SERVO
RFV OR In
TO INT CL.
REAR SERVO
RCV. OR LO
Fig. 7E-20 Lo Range
-
First Gear
LO RANGE
-
FIRST GEAR
Overrun engine braking in Lo range, first gear, is provided
by the rear servo applying the band to hold the reaction
carrier from clockwise rotation, viewed from front of car
(Fig. 7E-20).
1-2 accumulator oil is directed to the accumulator piston
which attempts to prevent the servo from applying.
Lo
range oil, directed to the servo piston which has the larger
area, applies the band. Because 1-2 accumulator is pre-
sent, the force applying the band is lowered. This provides
a smooth apply.
TO INT CL.
Q F A Q S F Q V O
REV.
OR LO
Fig. 7E-19 Drive and Super Range
-
Second Gear Fig. 7E-2 1 Lo Range
-
Second Gear