Drive Pinion; Installation And A Djustm Ent - Chevrolet Chevelle 1977 Repair Manual

Old Pinion
M arking
- 4
+ 4 + 0.008
+ 3 + 0.007
+ 2 + 0.006
+ 1 + 0.005
+ 0.004
0
+ 0.003
- 1
+ 0.002
- 2
- 3 + 0.001
- 4 0
5. W ith an arbor press, press differential side bearings
onto case using Tool J-22175. Do not install shims at this
time.
6. Place differential case in carrier and install bearing
caps. Care should be taken to install caps in original position.
Use m ark placed on caps and carrier at removal. Tighten caps
just enough to keep bearing caps in place.
7. Install dial indicator on carrier with indicator button
contacting back of ring gear (Fig. 4C-7). R otate differential
case and check for runout. If runout is greater than .002",
the assembly should be removed and the ring gear removed
from case. Again install differential case and check runout
at differential case flange.
8. Should runout of case flange be greater than .002",
the defect is probably due to bearings or differential case, and
should be corrected before proceeding further.
9. Position two screwdrivers between bearing cup and
carrier on opposite side of ring gear (away from dial indicator
side). Pull on screwdrivers and force differential case as far
as possible toward the dial indicator. Rock the ring gear to
set the bearings. W ith force still applied, set indicator at "0".
10. Reposition screwdrivers between bearing cup and
carrier on ring gear side. Pull on screwdrivers and force
differential case as far as possible tow ard center of carrier.
Repeat several times until the same reading is obtained.
Record the indicator reading. This will be the total am ount
of shims needed (less preload) for setting backlash later
during assembly.
11. Remove differential from carrier.

DRIVE PINION

Installation and Adjustment of Depth and
Preload
Ring gears and pinions are supplied in m atched sets
only. M atching numbers on both pinion and ring gear are
etched for verification. If a new gear set is being used, verify
the numbers of each pinion and ring before proceeding with
assembly.
On the button end of each pinion there is etched a plus
+ number, a minus - number, or a zero(0) number, which
indicates the best running position for each particular gear
FRONT WHEEL DRIVE
New Pinion M arking
- 2 - 1
- 3
+ 0.007 + 0.006 + 0.005
+ 0.004
+ 0.006 + 0.005
+ 0.005 + 0.004 + 0.003
+ 0.002
+ 0.004 + 0.003
+ 0.003 + 0.002 + 0.001
+ 0.002 + 0.001 0
+ 0.001 0 - 0.001
- 0.001 - 0.002
0
- 0.002 - 0.003
- 0.001
Fig. 4C -8--D rive P inion Shim C h a rt
+ 1 + 2
0
+ 0.002
+ 0.004 + 0.003
+ 0.003 + 0.002 + 0.001
+ 0.002 + 0.001 0
- 0.001
+ 0.001 0
- 0.001 - 0.002
0
- 0.001 - 0.002 - 0.003
- 0.002 - 0.003 - 0.004
- 0.004 - 0.005
- 0.003
- 0.004 - 0.005 - 0.006
set. This dimension is contolled by the shimming behind the
inner bearing cup. W henever baffles or oil slingers are used,
they become a part of the adjusting shim pack.
For example: If a pinion is etched + 3 , this pinion would
require .003" less shims than a pinion etched "0". This means
by removing shims, the mounting distance of the pinion is
increased by .003" which is just what a + 3 etching indicates.
Or if a pinion is etched -3 , we would want to add .003" more
shims than would be required if the pinions were etched "0".
By adding .003" shims, the m ounting distance of the pinion
was decreased .003" which is just what a -3 etching indicated.
If the old ring and pinion set is to be reused, measure
the old shim pack and build a new shim pack to this same
dimension. If baffle is in the axle assembly, it is considered
as part of the shim pack.
To change the pinion adjustment, shims are available in
thicknesses of .003", .005" and .010".
NOTE:
If baffle or slinger is bent or mutilated, it should
be replaced.
M easure each shim separately with a m icrometer and
add together to get total shim pack thickness from original
build up.
If a new gear set is being used, notice the plus or minus
etching on both the old and new pinion, and adjust the
thickness of the old shim pack to compensate for the
difference of these two figures.
For example: If the old pinion reads + 2 and the new
pinion is -2, add .004" shims to the original shim pack.
1. D eterm ine proper inner shim pack (for setting pinion
depth) by using chart (fig. 4C-8).
2. Install inner shim pack and oil slinger in inner cup
bore and drive inner cup into position using Tool J-2 1059
used with J-8092.
3. To the outer shim pack (for setting preload) add or
remove an equal am ount as was added or removed from the
inner shim pack.
4. Install outer cup in carrier bore, using installer J-7818
with Drive H andle J-8092.
5. Press inner pinion bearing cone and roller onto pinion
shaft using Installer J-9772 on arbor press as shown in Figure
4C-9.
4C-5
+ 3 + 4
+ 0.001 0
0 - 0.001
- 0.002
- 0.001
- 0.002 - 0.003
- 0.003 - 0.004
\
- 0.005
- 0.004
- 0.005 - 0.006
- 0.007
- 0.006
- 0.007 - 0.008