GMC 1989 Light Duty Truck Repair Manual page 184

4B4-8 101 / 2-INCH RING GEAR
T ighten
• T h e ring g ear bolts in seq u en ce to 163 N-m
(120
ft. lbs.).
7. Differential side bearings (18) using J 2 4 4 2 9 and
J 8 0 9 2 (figure 17).
• P lace J 8107 into the differential on the side
opposite of bearing installation to protect the
differential case.
• Drive the bearing onto the case using J 2 4 4 2 9
and J 80 92 .
8
Differential case (34) to the axle housing. R efer to
.
" Side B earing P reload A d ju s tm en t" in this section.
SIDE BEARING PRELOAD ADJUSTMENT
• T h e differential side bearing preload is adjusted by
two adjusting nuts in the differential bearing bore.
T h e bore and the bearing cap provide the m ating
threads for the bearing nut.
• T he differential must be initially preloaded in order
to determ ine the backlash of the g ear set. After the
backlash has been set, the final bearing preload is
set.
|-»<-| Install or C onnect (Figure 18)
Tool Required:
J 2 4 4 2 9 S id e
W rench
1. T h e bearing cups (20) to the differential bearings in
their original locations.
2. Differential assem b ly to the axle housing.
3. Adjusting nuts (19).
4. Bearing caps (20) and bolts (28) in their original
positions.
• A ssem bly the caps loosely.
• Loosen the right side adjusting nut, and tighten the
left side nut using J 2 4 4 2 9
contacts the drive pinion. Do not force the gears into
contact. This is the zero lash point.
• Back off the left adjusting nut approxim ately two
slots to obtain the initial backlash adjustm ent.
5. Adjusting nut lock (21) and lock bolt (22) to the left
nut.
B e a rin g B a c k la s h S p a n n e r
until the ring g ear
• Do not tighten.
Tighten the right adjusting nut firm ly to force the
case into solid contact with the left adjusting nut.
R otate the pinion several tim es to seat the bearings.
Loosen the right adjusting nut until it is free from its
bearing.
Tighten the right adjusting nut until it just contacts
the bearing. Additionally tighten the nut two slots for
used bearings, or three slots if new bearings are
installed.
6
Adjusting nut lock (21) and lock bolt (22) to the left
.
nut.
• Do not tighten.
• T h e b earing cap bolts (28) to 183 N-m (135 ft.
lbs.).
• M ea su re the ring g ear to pinion backlash. R efer to
" Backlash A d ju s tm en t" in this section.
BACKLASH ADJUSTMENT
1. Install a dial indicator to the case using a m agnetic
b ase (figure 19).
2. P lace the indicator stem at the heel end of a tooth.
• Set the dial indicator so that the stem is in line
with the g ear rotation and p erp en d ic u la r to the
tooth angle.
3. C h eck and record the backlash at th ree or four
points around the ring gear.
• T h e pinion m ust be held
checking backlash.
• T h e backlash should be the sam e at each
p o in t w ith in 0.0 5
b acklash varies m ore than 0.05 (0.002-inch),
c h e c k for burrs, a d is to rte d
uneven bolting conditions, or foreign m atter
b etw een the case and the ring gear.
4. T h e backlash at the m inim um lash point m easured
s h o u ld b e b e t w e e n
( 0 .0 0 5 - 0 .0 0 8 - in c h ) .
reading is 0.076-0.203 mm (0.003-0.008-inch).
sta tio n ary w hen
m m (0 .0 0 2 -in c h ). If th e
c a s e fla n g e ,
0 . 1 2 5 - 0 .2 0 0 m m
T h e m a x im u m a c c e p t a b le