Jeep 1997 Grand Cherokee Service Manual page 99

ARBOR DISC PINION HEIGHT BLOCK
ZG
ADJUSTMENTS (Continued)
Fig. 65 Gauge Tools In Housing—Typical
flush against the rearward surface of the pinion
height block (Fig. 63). Hold scooter block in place and
zero the dial indicator face to the pointer. Tighten
dial indicator face lock screw.
(7) With scooter block still in position against the
pinion height block, slowly slide the dial indicator
probe over the edge of the pinion height block.
(8) Slide the dial indicator probe across the gap
between the pinion height block and the arbor bar with
the scooter block against the pinion height block (Fig.
66). When the dial probe contacts the arbor bar, the dial
pointer will turn clockwise. Bring dial pointer back to
zero against the arbor bar, do not turn dial face. Con-
tinue moving the dial probe to the crest of the arbor bar
and record the highest reading. If the dial indicator can
not achieve the zero reading, the rear bearing cup or
the pinion depth gauge set is not installed correctly.
(9) Select a shim equal to the dial indicator read-
ing plus the drive pinion gear depth variance number
etched in the face of the pinion gear (Fig. 61). For
example, if the depth variance is –2, add +0.002 in.
to the dial indicator reading.
NOTE: If an oil slinger is used behind the inner pin-
ion bearing cone, deduct the thickness of the
slinger from the dial indicator reading and use that
total for shim selection.
DIFFERENTIAL BEARING PRELOAD AND GEAR
BACKLASH
INTRODUCTION
Differential side bearing preload and gear backlash is
achieved by selective shims positioned behind the differ-
ential side bearing cones. The proper shim thickness
can be determined using slip-fit dummy bearings D-348
in place of the differential side bearings and a dial indi-
cator C-3339. Before proceeding with the differential
bearing preload and gear backlash measurements, mea-
PINION BLOCK ARBOR DIFFERENTIAL
Fig. 66 Pinion Gear Depth Measurement—Typical
sure the pinion gear depth and prepare the pinion gear
for installation. Establishing proper pinion gear depth is
essential to establishing gear backlash and tooth con-
tact patterns. After the overall shim thickness to take
up differential side play is measured, the pinion gear is
installed, and the gear backlash shim thickness is mea-
sured. The overall shim thickness is the total of the dial
indicator reading and the preload specification added
together. The gear backlash measurement determines
the thickness of the shim used on the ring gear side of
the differential case. Subtract the gear backlash shim
thickness from the total overall shim thickness and
select that amount for the pinion gear side of the differ-
ential (Fig. 67). Differential shim measurements are
performed with axle spreader W-129-B removed.
BEARING SHIM ARBOR
DIFFERENTIAL AND DRIVELINE
Fig. 67 Axle Adjustment Shim Locations
DIAL INDICATOR SCOOTER BLOCK DRIVE PINION GEAR DEPTH SHIM
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