Jeep 1997 Grand Cherokee Service Manual page 97

ZG
CLEANING AND INSPECTION (Continued)
Wash bearings with solvent and towel dry, or dry
with compressed air. DO NOT spin bearings with
compressed air. Cup
replaced as matched sets only.
Clean axle shaft tubes and oil channels in housing.
Inspect for;
• Smooth appearance with no broken/dented sur-
faces on the bearing rollers or the roller contact sur-
faces.
• Bearing cups must not be distorted or cracked.
• Machined surfaces should be smooth and with-
out any raised edges.
• Raised metal on shoulders of cup bores should
be removed with a hand stone.
• Wear and damage to pinion gear mate shaft,
pinion gears, side gears and thrust washers. Replace
as a matched set only.
• Ring and pinion gear for worn and chipped
teeth.
• Ring gear for damaged bolt threads. Replaced as
a matched set only.
• Pinion yoke for cracks, worn splines, pitted
areas, and a rough/corroded seal contact surface.
Repair or replace as necessary.
• Preload shims for damage and distortion. Install
new shims, if necessary.
ADJUSTMENTS
PINION GEAR DEPTH
GENERAL INFORMATION
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
61). A plus (+) number, minus (–) number or zero (0)
is etched into the face of the pinion gear. This num-
ber 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 setting from
the center line of the ring gear to the back face of the
pinion is 92.08 mm (3.625 in.). The standard depth
provides the best gear tooth contact pattern. Refer to
Backlash and Contact Pattern Analysis paragraph in
this section for additional information.
Compensation for
achieved with select shims. The shims are placed
behind the rear pinion bearing cup (Fig. 62).
If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion gear. Add or subtract the thickness of
the original depth shims to compensate for the differ-
ence in the depth variances. Refer to the Depth Vari-
ance chart.
and bearing must
pinion depth variance
DIFFERENTIAL PRODUCTION NUM- GEAR MATCHING NUMBER (SAME AS RING GEAR NUM- BERS BEARING SHIM BER)
DIFFERENTIAL AND DRIVELINE
be
Fig. 61 Pinion Gear ID Numbers
Fig. 62 Shim Locations
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 drive
pinion gear (–1, –2, 0, +1, +2, etc.). The numbers rep-
is
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
DRIVE PINION GEAR GEAR DRIVE DEPTH SHIM VARIANCE DEPTH PINION
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