Jeep 1997 Grand Cherokee Service Manual page 173

SPECIAL TOOL C-3288–B
AXLE HOUSING
DIFFERENTIAL CASE
ZG
ADJUSTMENTS (Continued)
(6) Install the marked bearing caps in their correct
positions. Install and snug the bolts.
(7) Thread guide stud C-3288-B into rear cover
bolt hole below ring gear (Fig. 75).
(8) Attach dial indicator C-3339 to Guide Stud
C-3288-B. Position the dial indicator plunger on a
flat surface between the ring gear bolt heads (Fig.
75).
Fig. 75 Differential Side play Measurement
(9) Push and hold differential case to pinion gear
side of axle housing.
(10) Zero dial indicator face to pointer.
(11) Push and hold differential case to ring gear
side of the axle housing.
(12) Record dial indicator reading.
(13) Add the dial indicator reading to the starting
point shim thickness to determine total shim thick-
ness to achieve zero differential end play.
(14) Add 0.012 in. (0.3 mm) to the zero end play
total. This new total represents the thickness of
shims to compress, or preload the new bearings when
the differential is installed.
(15) Rotate dial indicator out of the way on guide
stud.
(16) Remove differential case, dummy bearings,
and starting point shims from axle housing.
(17) Install pinion gear in axle housing. Install the
yoke and establish the correct pinion rotating torque.
(18) Install differential case and dummy bearings
in axle housing (without shims) and tighten retaining
cap bolts snug.
(19) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads (Fig. 75).
DIFFERENTIAL AND DRIVELINE
(20) Push and hold differential case toward pinion
gear.
(21) Zero dial indicator face to pointer.
(22) Push and hold differential case to ring gear
side of the axle housing.
(23) Record dial indicator reading.
(24) Subtract 0.002 in. (0.05 mm) from the dial
indicator reading to compensate for backlash between
ring and pinion gears. This total is the thickness of
shim required to achieve proper backlash.
(25) Subtract the backlash shim thickness from
the total preload shim thickness. The remainder is
the shim thickness required on the pinion side of the
axle housing.
(26) Rotate dial indicator out of the way on guide
stud.
(27) Remove differential case and dummy bearings
from axle housing.
(28) Install new side bearing cones and cups on
differential case.
(29) Install spreader W-129-B on axle housing and
spread axle opening enough to receive differential
case and side bearing shims.
(30) Place side bearing shims in axle housing
against axle tube ends.
(31) Install differential case in axle housing.
(32) Remove spreader from axle housing.
(33) Rotate the differential case several times to
seat the side bearings.
(34) Position the indicator plunger against a ring
gear tooth (Fig. 76).
(35) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(36) Zero dial indicator face to pointer.
(37) Push and hold ring gear downward while not
allowing the pinion gear to rotate. Dial indicator
reading should be between 0.12 mm (0.005 in.) and
0.20 mm (0.008 in.). If backlash is not within specifi-
cations transfer the necessary amount of shim thick-
ness from one side of the axle housing to the other
(Fig. 77).
(38) Verify differential case and ring gear runout
by measuring ring to pinion gear backlash at several
locations around the ring gear. Readings should not
vary more than 0.05 mm (0.002 in.). If readings vary
more than specified, the ring gear or the differential
case is defective.
After the proper backlash is achieved, perform the
Gear Contact Pattern Analysis procedure.
GEAR CONTACT PATTERN ANALYSIS
The ring and pinion gear teeth contact patterns
will show if the pinion gear depth is correct in the
axle housing. It will also show if the ring gear back-
lash has been adjusted correctly. The backlash can be
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