GMC 1982 Light Duty Truck Service Manual page 493

2. Assemble remaining plates and discs to splines of side
gear ring, being sure they are assembled in the same
order of removal. The convex (bulged) side of the
Belleveille friction disc (5) should be toward the side
gear and it should nest into the Belleville friction plate
(4 ).
3. Place assembled side gear ring with plates and discs in
flanged half of differential case.
4. Install side gear and cross shafts with pinions.
5. In the order listed install the following: (1) side gear,
(2) side gear ring, (3) flat plate with tabs, (4) flat disc
with teeth, (5) flat plate with tabs, (6) Belleville disc
with convex (bulged) side up, or toward side gear, (7)
Belleville plate, with convex (bulged) side up, or side
toward gear.
6. Position plain half of differential case over previously
assembled parts with scribe markings on both halves of
case in alignment.
7. Install differential case bolts, but do not tighten at this
time.
8. Before tightening bolts, use axle shafts and align
splines of the side gear and side gear ring, on each side.
Tighten bolts evenly and alternately. Remove axle
shafts.
9. Observe if Power-Lok
assembled properly. Each pinion cross shaft can be
tight on its ramp or if there is clearance it should be
only a few thousandths, and it should be equal at all
four cross shaft ends.
Testing Procedure
The Power-Lok can be effectively tested for correct
operation by placing one rear wheel on good dry pavement
and the other on ice, snow mud, gravel, grease, etc.
It can easily be determined whether or not the non­
slipping wheel is providing pulling power. The procedure
should then be repeated with the opposite wheels on the dry
and slippery surfaces.
The above testing procedure is a rough test that can be
made by the owner of the vehicle. However, if it is suspected
that the unit is not operating properly, it can be checked by
the following procedure.
Be sure the transmission is in neutral. Raise one wheel
off the floor and place a block in the front and rear of the
opposite wheel. Remove the hub cap and install a special
tool across two wheel studs. Apply a torque wrench to
special tool. Disregard breakaway torque and observe only
the torque required to continuously turn the wheel smoothly.
If the torque reading is less than 54 N-m (40 ft. lbs.) or
more than 280 N-m (200 ft. lbs.), the unit should be
disassembled and the necessary repairs made.
REAR AXLE 4B6-11
components have been