Jeep 1997 Grand Cherokee Service Manual page 170

PRODUCTION NUM- GEAR MATCHING NUMBER (SAME AS RING GEAR NUM- PINION GEAR AXLE HOUSING BEARING CUP BERS BER)
3 - 112 DIFFERENTIAL AND DRIVELINE
ADJUSTMENTS (Continued)
pinion gear are etched into the face of each gear (Fig.
67). 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 109.52 mm (4.312 in.). The standard depth
provides the best teeth contact pattern. Refer to
Backlash and Contact Pattern Analysis Paragraph in
this section for additional information.
Fig. 67 Pinion Gear ID Numbers
Compensation for
achieved with select shims. The shims are placed
under the inner pinion bearing cone (Fig. 68).
Fig. 68 Shim Locations
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 charts.
PINION COLLAPSIBLE GEAR DRIVE PINION
pinion depth variance
BEARING SPACER VARIANCE DEPTH PINION DEPTH SHIM
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus amount needed.
Note the etched number on the face of the drive
pinion gear (–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 shim(s). If the num-
ber is positive, subtract that value from the thickness
of the depth shim(s). If the number is 0, no change is
necessary. Refer to the Pinion Gear Depth Variance
Chart.
PINION DEPTH MEASUREMENT AND
ADJUSTMENT
Measurements are taken with pinion cups and pin-
ion bearings installed in housing. Take measure-
ments with Pinion Gauge Set 6955, Dummy Bearing/
Arbor Disc Set 6956, and Dial Indicator C-3339 (Fig.
69).
(1) Assemble Pinion Height Block 6739, Pinion
Block 8144, and rear pinion bearing onto Screw 6741
(Fig. 69).
(2) Insert assembled height gauge components,
rear bearing and screw into axle housing through
pinion bearing cups (Fig. 70).
(3) Install front pinion bearing and Cone 6740
hand tight (Fig. 69).
(4) Place Arbor Disc 6927 on Arbor D-115-3 in posi-
tion in axle housing side bearing cradles (Fig. 71).
is
Install differential bearing caps on Arbor Discs and
tighten cap bolts. Refer to the Torque Specifications
in this section.
NOTE: Arbor Discs 6927 have different step diame-
ters to fit other axle sizes. Pick correct size 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 surface of the pinion height block.
Hold scooter block in place and zero the dial indica-
tor 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.
Observe how many revolutions counterclockwise the
dial pointer travels (approximately 0.125 in.) to the
out-stop of the dial indicator.
(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. 72). When the dial probe contacts the arbor bar,
the dial pointer will turn clockwise. Bring dial
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