Pontiac FIREBIRD 1972 Service Manual page 371

TYPE C STANDARD DIFFERENTIAL 4C-3
gears are held in one position in the differential case by the
pinion shaft, power is distributed evenly to each axle shaft
providing the road surface resistance to each rear wheel is
equal.
If the road surface at one rear wheel is soft or slippery it
will offer less resistance to spin for that wheel. When this
situation occurs the differential case still tries to transmit
equal power to each side gear but in meeting with greater
resistance to motion by one side gear, the pinion gears will
rotate or walk around this side gear which in turn aids the
pinion gears and differential case in distributing increased
power to the side gear of less resistance thus causing the
one wheel to spin.
The differential acts in the same manner when the car is
turning a corner except that both wheels are turning. In
this case the inside wheel and side gear are rotating slower
than the outside wheel and side gear. The pinion gears are
at this time revolving with the slower side gear and also
rotating on the pinion shaft to increase the speed of the
outside side gear and wheel.
USAGE OF C DIFFERENTIAL
The type "C" differential is used on all A Series models
with the 455 cu. in. engine, all 455 cu. in. G Series models,
all F and X Series models and all B Series Models, except
those axles identified by a "B" or "0" last letter in the
three letter axle code. The type "C" differential can be
distinguished from standard differentials by this last letter
of the three letter axle code. Type "C" identifying codes
are as follows: A and G Series
-
"K", B Series
-
"G", "K",
"P" or "M", F Series
................
"G", X Series
-
"G".
GEAR RATIO CODES AND IDENTIFICATION OF C
DIFFERENTIAL
The three letter identifying code for the type "C" differen-
tial is located in the same place as in the standard differen-
tial
-
the front face of the right hand axle tube next to the
carrier housing. After the axle code has been determined,
reference should be made to the axle charts at the end of
Section 4A to determine ratio, etc.
SERVICE PROCEDURES
AXLE SHAFT, BEARING A N D SEAL
REMOVE
1. Raise and suitably support car leaving the rear wheels
and differential assembly suspended.
CAUTION: Use care not to crush exhaust sys-
tem 'itick-under9'pipe on B Series station wag-
ons when using an axle engaging hoist.
2. Remove rear wheel(s) and brake drum(s).
3. Remove differential carrier cover and allow lubricant
to drain.
4. Remove pinion shaft lock bolt and pinion shaft. See
Fig. 4C-2.
5. Push axle shaft(s) inward to permit removal of "C"
locks then remove axle shaft(s). See Fig. 4C-3.
6. Install axle shaft bearing and seal remover 5-22813
(all A, X and G Series "G" or "K" coded axles), or
5-23689 (B Series, "G", "K", "P" or "M" coded
axles and F Series, G coded axle) and slide hammer
and remove the bearing and seal. See Fig. 4C-4.
INSTALL
1. A, X and G Series
-
Using special tool 5-5292, install
the bearing and then the seal. See Fig. 4C-5.
B and F Series
-
Because the axle shaft bearing and
seal are each installed to a predetermined depth in the
axle tubes, they must be installed separately using
individual special tools. Install the bearing first, using
special tool 5-23690, and'then install the seal using
special tool 5-21 128.
2. Carefully insert axle shaft through the seal and bear-
ing as far as possible through the side gear.
CAUTION: Care should be taken when install-
ing the axle shaft, as careless installation could
damage the seal.
Fig. 4C-2 Pinion Shaft Lock Bolt