GMC 1976 ZEO 6083 Maintenance Manual page 183

3C- 2 0 FINAL DRIVE
Figure 54-Checking Ring Gear To Pinion Gear
Backlash
2. Check backlash at three or four points around
ring gear. Lash must not vary over .002" around ring
gear .
NOTE :
Pinion must be held stationary when
checking backlash . If variation is over .002"
check for burrs, uneven bolting or distorted case
and make corrections as necessary.
3. Backlash at the point of minimum lash should
be between .005" and .009" for all new gears. If
original ring gear and pinion was installed, backlash
should be set at the same reading obtained in Step 4
of the Final Drive Disassembly procedure, provided
reading was within specifications .
4. Ifbacklash is not within specifications, correct
by increasing thickness of one differential shim and
decreasing thickness of other shim the same amount.
This will maintain correct differential side bearing
pre-load.
For each .001 " change in backlash desired, trans-
fer .002" in shim thickness. To decrease backlash
.001" INCREASE thickness of right shim .002" and
DECREASE thickness of left .002" . To increase
backlash .002" DECREASE thickness of right shim
.004" and INCREASE thickness of left shim .004" .
5. When backlash is correctly adjusted, remove
spreader . Install the bearing caps and bolts. Torquer
to 75 ft. lbs.
6. Install new output shaft seals as shown in Fig-
ure 10 and 14.
NOTE:
Left output shaft seal in installed with
vent hole toward top offinal drive housing in the
in-car position .
7. Install new gasket on housing. Install cover,
torque cover bolts to 30 ft. lbs.
Fill final drive with fluid to "FILL LEVEL" line
stamped on cover near fill hole.
Use only Gear Lubricant No. 1051022 or equiva-
lent.
NOTE:
If final drive was removed without
removing the transmission, do not install gasket,
cover or lubricant until final drive has been in-
stalled in vehicle.
FINAL DRIVE SPECIFICATIONS
LUBRICATION
Capacity . . . . . . ... . . ... . .... . ... . . ... . . ... . .... . ... . . . .. . . .. . . .. . . ... . ... . . .. . . . .. . . .... . ... . . . .. . . ... . . ... . . ... . . .. . . . .. . . ... . ..4 Pints
Replenish . . .. . . .... . ... . .... . . .. . . . .. . . .... .... . . .. . . . .. . . .. . . .. . Special Lubricant No. 1051022 or equivalent
ADJUSTMENTS
Backlash . . . . .. . . .... . ... . .... . ... . . . .. . . .... .... . . .. . . . .. . . .. . . .. . . ... . . .. . . .. . . . .. . . .... . ... . . . .. . . .... . ... . . ... . . ... .005" to .009"
Pinion Bearing Pre-load
New Bearings . ... . . ... . . .. . . . ... . .... .... . . .. . . . .. . . ... . .. . . ... . . .. . . .. . . . ... . .... . ... . . . .. . . .... . ... . . ... . . . 2 to 15 in. lbs.
Old Bearings .. . ... . . ... . . ... . . ... . .... . . .. . . . .. . . ... . ... . . .. . ... . . .. . . . .. . . ... . .... . . ... . . ... . .... . ... . . . ... . ... 2 to 5 in . lbs .
Side Bearing Pre-load
New Bearings . ... . . ... . . ... . . ... . .... . ... . ... . . . .. . . .. . . .. .10 to 15 in. lbs. over Pinion Bearing Pre-load
Old Bearings .. . ... . . ... . . .. . . . ... . .... . ... . . .. . . . .. . . .. . . .. . . ... 5 to 7 in. lbs. over Pinion Bearing Pre-load
GEAR RATIO .... . ... . . ... . . .. . . . ... . .... . ... . . .. . . . .. . . ... . .. . . ... . . .. . . .. . . . ... . .... . ... . . . . . . . .... . ... . . ... . . .. . . . .. . . ... . .. 3 .07 :1