Assembly Of The Rear Axle - GMC 1989 Light Duty Truck Repair Manual

PINION AND RING GEAR
Inspect
Pinion and ring gear teeth for cracking, chipping,
scoring, or excessive wear.
Pinion splines for wear.
Pinion flange splines for wear.
The fit of the pinion on the pinion flange.
The sealing surface of the pinion flange for nicks,
burrs, or rough tool marks which would cause
damage to the seals' inside diameter and result in
an oil leak.
Replace all worn or broken parts.
Ring and pinion gears are matched sets and are
both replaced any time a replacement of either is
necessary.
BEARINGS
Inspect
l v
Bearings visually and by feel.
The bearings should feel smooth when oiled and
rotated while applying as much hand pressure as
possible.
The large end of the bearing rollers for wear. This is
where tapered roller bearing wear is most evident.
Bearing cups for wear, cracks, b rin e llin g and
scoring.
Bearings and cups are only replaced as sets.
If the rear axle was operated for an extended period
of time with very loose bearings, the ring gear and
drive pinion will also require replacement.
Low mileage bearings may have minute scratches
and pits on the rollers and the bearing cups from the
initial pre-load. Do not replace a bearing for this
reason.
Bearing cups for cracks or chips.
SHIMS
L*
Inspect
• Shims for cracks and chips. Damaged shims should
be replaced with an equally sized service shim.

ASSEMBLY OF THE REAR AXLE

+«- Install or C onnect (Figures 1, 7 and 8)
Tools Required:
J 7817 Front Pinion Bearing Cup Installer
J 7818 Rear Pinion Bearing Cup Installer
J 8092 Driver Handle
Pinion bearing cups (15) and (18) using J 7817,
J 7818 and J 8092.
PINION DEPTH ADJUSTMENT (Figure 9)
Tools Required:
J 21777-40 Rear Pilot Washer
J 21777-42 Front Pilot Washer
J 21777-43 Stud Assembly — Bolt
J 21777-45 Side Bearing Discs
J 23597-1 Arbor
J 23597-11 Gage Plate
J 8001 Dial Indicator
1/2 5
7 AND 7 /8-INCH RING GEAR AXLES 4B1-5
1. Clean all the gage parts.
2. Lubricate the front and rear pinion bearings with
axle lubricant.
3. Place the bearings (15) and (18) into the pinion
bearing cups.
4. In s ta ll J 21777-40, J 21777-42, J 21777-43 and
J 23597-11 to the pinion bore (figure 9).
5. Hold the stud stationary at the flats of the stud.