Chevrolet 1977 light duty truck, Service Manual

Page: 365 / 861

ON-VEHICLE SERVICE
8 - 1 / 2 and 8 - 7 / 8 RING
GEAR AXLE
AXLE ASSEMBLY
C onstruction o f the axle assembly is such that
service op eratio n s m ay be p e rfo rm e d with the housing
installed in the vehicle or with the housing installed in a
holding fixture. The following rem oval and installation
procedure is necessary only w hen the housing requires
replacem ent.
CAUTION: See C A U T I O N on page 1 o f this
section, regarding A x le Assembly fasteners.
Removal
1. Raise vehicle on hoist.
2. Sup p o rt rear axle assembly with suitable lifting
device, so that tension is relieved in springs and shock
absorbers.
3. Rem ove tru n n io n bearing
" U "
bolts from the
axle co m p an io n flange, separate tru n n io n from flange,
position propeller sh a ft to one side and tie it to fram e
side rail.
N O T E : Secure tru n n io n bearing caps to trunnion,
using m asking tape or a large ru b b e r band, to
p revent loss o f bearings.
4. Disconnect shock absorbers at lower attachm ent
points and position out o f the way.
5. Disconnect axle vent hose from vent connector
a n d position vent hose to one side.
6. Disconnect hydraulic brake hose at connector on
axle housing. Remove brake d rum , disconnect park in g
brake cable at actuating levers and at flange plate. R efer
to Section 5 for cable rem oval and brake details. Remove
axle " U " bolt nuts,
" U "
bolts, spacers an d clam p plates.
7. Lower axle assembly and remove from vehicle.
Installation
1. Position axle assembly und er vehicle and align
w ith springs.
2. Install spacer, clam p plate and " U " bolts to axle
assembly, loosely install re ta in in g nuts to " U " bolts.
3. Position shock absorbers in lower attach m en t
brackets and loosely install nut to retain shock.
4. C onnect axle vent hose to vent connector at
carrier.
5. C onnect hydraulic brak e hose to connector on
axle housing, connect p ark in g brak e cable to actuating
levers. Install brake d rum and wheel and tire a s s e m b l y -
bleed brakes and adjust p ark in g brake as outlined in
applicable portion o f Section 5.
6. Reassem ble the propeller shaft to com panion
flange, m ak in g sure that b earin g caps are indexed in
flange seat. T o rq u e b earin g cap retaining nuts to
specifications.
7. Position vehicle so th at weight is placed on
suspension com ponents an d torque affected parts to
specifications.
8. Lower vehicle and remove from hoist.
AXLE SHAFT
Removal
1. Raise vehicle on hoist. Remove wheel and tire
assembly and brake drums.
2. Clean all dirt from area o f carrier cover.
3. D r a in lubricant fro m carrier by rem oving cover.
4. Remove the differential pinion shaft lock screw
and the differential pinion shaft as shown in figure 4B-
14.
5. Push flanged end o f axle shaft toward center o f
vehicle and remove
" C "
lock from button end o f shaft.
6. Remove axle shaft from housing, being careful
not to d am ag e oil seal.
N O TE: Axles e quipped with 8 - 7 /8 " ring gears and
Eaton Locking differentials use a thrust block on
the pinion sh aft which affects the removal o f axle
shafts as noted below.
1. Raise the vehicle on a hoist. Remove both rear
wheel an d tire assemblies and both re a r brake drums.
2. Remove the re a r cover an d d ra in the lubricant.
3. Rotate the case to the position shown in figure
4B-15. Support the pinion shaft so th at it can n o t fall
into the case, then remove the lock screw.
4. Carefully w ithdraw the pinion shaft part-way
out, as shown in figure 4B-16. Rotate the case until the
shaft touches the housing.
5. Reach into the case w ith a screwdriver or
sim ilar tool, and rotate the C-lock until its open end
points directly inward, as shown in figure 4B-17. The axle
shaft cannot be pushed inward until the C-lock is
properly positioned.