Chevrolet 1977 10 Series, Руководство по ремонту, Страница: 114 / 468

4B-42 OVERHAUL MANUAL
Fig. 14D—In s ta llin g Spring Pack
20. Check alig n m en t o f sp rin g re ta in e r w ith side gears.
Slight m ovem ent o f the sp rin g pack can be m ade if
necessary.
21. Install side b earings a n d rin g g e a r to case using
procedure outlined fo r the con v en tio n al differential.
22. Place differential in c a rrie r and adjust b earin g s and
b ack lash
as o u tlin e d fo r the c o n v e n tio n a l
differential.
23. Check o p eratio n o f u n it as follows:
a. R aise re a r o f vehicle until re a r w heels are off
the ground, and rem ove one w heel an d tire
assem bly.
b. A ttach A d ap ter J-5748 to axle sh a ft flange and
install a 1/2-13 bolt in to ad a p te r, shown in
Figure 15D.
c. W ith w heel and tire assem bly still on vehicle
held firmly to p rev en t tu rn in g , m easure torque
req u ired to ro tate o pposite axle sh a ft w ith a
0-150 lb. torque w rench attach ed to J-5748.
T orque req u ired to ro ta te axle sh a ft should be
no less th a n 40 ft-lbs.
CHEVROLET POSITRACTION-FIGURE 16D
A C hevrolet produced P o sitractio n differential u n it is
used o ptionally in 8 1/2 inch rin g g ear axles. In dividual
com ponents o f this p o sitractio n u n it are not in te rc h a n g e ­
able w ith o th er design units.
Disassembly
1. R em ove rin g gear and side b earin g s follow ing the
procedures established fo r the co n ventional differ­
en tial unit. Rem ove p in io n sh aft.
2. U sing a wide, blunt in stru m e n t such as a d rift or
block o f w ood, drive the p re lo a d sp rin g from the
case.
3. S upport an axle sh aft in a vise, and slide the case
into the sh aft; then turn the case to rem ove both
p inions and thrust w ashers.
N O T E : The p in io n sh a ft m ay be p a rtially
installed to aid in ro ta tin g the case.
4. Rem ove the case from the axle sh a ft a n d rem ove
both side gears, clutch packs a n d shim s. M ark the
gears, clutch packs and shim s for re in stallatio n in
sam e positions.
Inspection
Check the clutch plates and discs fo r w ea r and signs o f
o verheating. Check the co n d itio n o f the p relo ad spring.
Check the gear teeth for signs o f w ear. R eplace p a rts as
needed. C lean all parts to be used fo r assem bly.
N O T E : T he force re q u ire d to com press the
preload spring to 1-5/16 inches should be 300
lbs. ± 30 lbs.
Reassembly
1. L u b ric a te the clutch discs a n d p late s w ith
p o sitraction lubricant.
2. A lternately position clutch plates a n d discs on a
side gear, beg in n in g and e n d in g w ith a clutch plate.
3. Position the side gear, clutch pack and o rig in al
shim into the case.
4. Install both p in io n gears an d th ru st w ashers into
the case, an d install p in io n sh aft.
5. Place the case onto an axle sh a ft su p p o rte d in a
vise.
6. Insert a screw driver betw een the p in io n sh a ft and
the face o f the side gear. F orce the screw driver in
until the clutch pack is com pressed.
7. Check the backlash betw een side g e a r and p in io n
gears. If backlash does n o t fall into the ra n g e o f
.005" to .008", adjust the shim d im en sio n as
req u ired . Increasing shim thickness will decrease
b ack lash ; to in c rease b a c k la sh , d ecrease the
thickness o f the shim .
Fig. 15D—Measuring Positraction Rotating Torque