Jeep Cherokee 2000 Service Manual - page 162
ADJUSTMENTS
8 1/4 AXLE PINION GEAR DEPTH
GENERAL INFORMATION
Ring gears and pinions are supplied as matched
sets only. The identifying numbers for the ring gear
and pinion are etched into the face of each gear (Fig.
51). A plus (+) number, minus (–) number or zero (0)
is etched into the face of the pinion. This number is
the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard depth provides the
best gear tooth contact pattern. Refer to Backlash
and Contact Pattern Analysis paragraph in this sec-
tion for additional information.
Compensation
for
pinion
depth
variance
is
achieved with select shims. The shims are placed
behind the rear pinion bearing (Fig. 52).
If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion. Add or subtract the thickness of the
original depth shims to compensate for the difference
in the depth variances. Refer to the Depth Variance
chart.
Note where Old and New Pinion Marking columns
intersect.
Intersecting
figure
represents
plus
or
minus the amount needed.
Note the etched number on the face of the pinion
gear head (–1, –2, 0, +1, +2, etc.). The numbers rep-
resent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shims. If the number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.
PINION DEPTH MEASUREMENT AND ADJUSTMENT
Measurements are taken with pinion bearing cups
and pinion bearings installed in the axle housing.
Take measurements with Pinion Gauge Set and Dial
Indicator C-3339 (Fig. 53).
(1) Assemble Pinion Height Block 6739, Pinion
Block 8540, and rear pinion bearing onto Screw 6741
(Fig. 53).
(2) Insert assembled height gauge components,
rear bearing, and screw into axle housing through
pinion bearing cups (Fig. 54).
(3) Install front pinion bearing and Cone-Nut 6740
hand tight (Fig. 53).
(4) Place Arbor Disc 8541 on Arbor D-115-3 in posi-
tion in axle housing side bearing cradles (Fig. 55).
Install differential bearing caps on Arbor Discs and
tighten cap bolts to 41 N·m (30 ft. lbs.).
NOTE: Arbor Discs 8541 has different step diame-
ters to fit other axles. Choose proper step for axle
being serviced.
(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(6) Place Scooter Block/Dial Indicator in position
in axle housing so dial probe and scooter block are
flush against the rearward surface of the pinion
height block (Fig. 53). Hold scooter block in place and
zero the dial indicator face to the pointer. Tighten
dial indicator face lock screw.
Fig. 51 Pinion Gear ID Numbers
1 – PRODUCTION NUMBERS
2 – DRIVE PINION GEAR DEPTH VARIANCE
3 – GEAR MATCHING NUMBER (SAME AS RING GEAR
NUMBER)
Fig. 52 Shim Locations
1 – AXLE HOUSING
2 – COLLAPSIBLE SPACER
3 – PINION BEARING
4 – PINION DEPTH SHIM
5 – PINION GEAR
6 – BEARING CUP
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8 1/4 REAR AXLE
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