JEEP YJ 1995 Service And Owners Manual

(5) Lubricate all differential components with hy-
poid gear lubricant.
PINION GEAR DEPTH 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. 39). A
plus (+) number, minus (-) number or zero (0) is
etched into the face of the pinion gear. 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 setting from the cen-
terline of the ring gear to the back face of the pinion
is 92.1 mm (3.625 inches) for Model 30 axles (Fig.
40). The standard depth provides the best teeth con-
tact pattern.THE BUTTON END ON THE PINION GEAR
HEAD IS NO LONGER A MACHINED-TO-SPECIFI-
CATIONS SURFACE. DO NOT USE THIS SUR-
FACE FOR PINION DEPTH SET-UP OR
CHECKING (Fig. 40).
Compensation for depth variance is achieved by a
selected thickness oil slinger (production) or shims
(service). The slinger is placed between the inner pin-
ion bearing cone and gear head (Fig. 41). The shim
pack is placed under the inner (rear) bearing cup for
service. To change the pinion adjustment, shims are
available in thicknesses of 0.003, 0.005, and 0.010
inch.The oil slinger or baffle must be measured
and the thickness included with the total shim
pack.
Fig. 38 Ring Gear Bolt Installation
Fig. 39 Pinion Gear ID Numbers
Fig. 40 Pinion Gear Head
Fig. 41 Shim Locations
JFRONT SUSPENSION AND AXLE 2 - 39

New gear set: note the depth variance etched
into both the original and the replacement pin-
ion gear. Add or subtract the thickness of the
original depth shims to compensate for the dif-
ference in the depth variances. Refer to the
Depth Variance charts.
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or mi-
nus amount needed.
For example, if old pinion is plus (+) 1 and the new
pinion is minus (-) 3, intersecting figure is (+)0.004
inch (0.10mm). Add this amount to the original shim.
Or if the old pinion is (-) 3 and the new pinion is (-)
2, intersecting figure is (-)0.001 inch (0.025mm). Sub-
tract this amount from original shim.Refer to the
Pinion Gear Depth Variance Chart.
DIFFERENTIAL AND PINION MEASUREMENT
DIFFERENTIAL ZERO END PLAY
MEASUREMENT
(1) Place Master Differential Bearing D-134
(D-348) on the case hubs (Fig. 42). Install differential
case into housing.
(2) Install a pilot stud at the right side of housing.
Attach Dial Indicator to the pilot stud. Load indica-
tor plunger against the back of the ring gear (Fig.
43).
(3) Insert a small pry bar between the bearing cap
and left side of differential case. Pry the case as far
as possible to right side (Fig. 43). Zero the dial indi-
cator pointer.
(4) Pry the case to left side andrecordthe travel
distance.The measurement above is the shim thickness
necessary for case zero end-play. The total
thickness will be determined during the ring
gear backlash adjustment.
(5) Remove indicator, pilot stud and differential
case from housing.
PINION GEAR DEPTH MEASUREMENT
Pinion gear depth measurement is necessary
when;
PINION GEAR DEPTH VARIANCE
Fig. 42 Master Bearing Tools On Hubs
2 - 40 FRONT SUSPENSION AND AXLEJ

²Axle housing or differential case is replaced
²Pinion select shim pack is unknown
²Ring and pinion gears are replaced
Measurements are done with pinion cups and pin-
ion bearings installed in housing. Take measure-
ments with Pinion Gauge Set 6774, Pinion Block
6733 and Dial Indicator C-3339 (Fig. 44).
(1) Install the pinion front bearing cup with In-
staller D-144 and Handle C-4171 (Fig. 45).(2) Install the bearing cup with Installer D-146
and Driver Handle C-4171 (Fig. 46). Ensure cup is
correctly seated.
(3) Assemble Pinion Gauge Set, Pinion Block and
pinion bearings. Install assembly into differential
pinion gear bore and hand tighten cone (Fig. 47).
(4) Place Arbor Disc 6732 on Arbor D-115-3 and po-
sition in the bearing cradles (Fig. 48). Install differ-
ential bearing caps on Arbor Discs and tighten caps
snug only.
Arbor Discs have different steps to fit other
axle sizes. Pick correct size step for axle being
serviced.
(5) Firmly place Scooter Block and Dial Indicator
on pinion height block tool and zero the dial indicator
pointer.
(6) Slide the Scooter Block across the arbor while
Fig. 43 Differential Case End Play Measurement
Fig. 44 Pinion Gear Depth Gauge Tools
Fig. 45 Pinion Front Bearing Cup Installation
Fig. 46 Pinion Rear Bearing Cup Installation
JFRONT SUSPENSION AND AXLE 2 - 41

observing indicator (Fig. 49). Record the longest
travel distance, whether inward (-) or outward (+),
indicated by the pointer.The plunger travel, plus or minus the vari-
ance etched in the gear, is the required thick-
ness for the depth shims.
(7) Measure the thickness of each depth shim with
a micrometer. Combine the shims necessary for total
required shim pack thickness.Include oil slinger
or baffle thickness with the total shim pack
thickness.
(8) Remove the measurement tools from the differ-
ential housing.
PINION GEAR ASSEMBLY/INSTALLATION
(1) Remove rear pinion bearing cup with Remover
D-149 and Handle C-4171. Place shims (and baffle if
equipped) in the pinion gear rear bearing bore. In-
stall the bearing cup with Installer D-146 and Driver
Handle C-4171. Ensure cup is correctly seated.
(3) Install rear bearing and oil slinger on pinion
gear with Installer W-262 until completely seated
(Fig. 50).
(4) Assemble preload shims onto pinion shaft.
(5) Install pinion front bearing cone into cup and
end yoke thrust washer.
(6) Apply a light coat of gear lubricant on lip of
new pinion seal. Install seal with Installer D-163 and
Handle C-4171 (Fig. 51).
(7) Install pinion gear into differential housing.
(9) Install yoke with Installer W-162-D and
Wrench C-3281 (Fig. 52).
(10) Install the yoke washer andold nuton the
pinion gear. Use Flange Wrench C-3281 to retain the
yoke (Fig. 53). Tighten nut to 216-352 Nzm (160-260
ft.lbs.) torque.
Fig. 47 Pinion Height Block
Fig. 48 Gauge Tools In Housing
Fig. 49 Pinion Depth Measurement
Fig. 50 Pinion Rear Bearing Installation
2 - 42 FRONT SUSPENSION AND AXLEJ

(11) Check bearing rotating torque with an inch
pound torque wrench (Fig. 54).If torque to rotate is
within specification, remove old nut and install new
nut. The torque necessary to rotate the pinion gear
should be;
²Original Bearings: 1 to 3 Nzm (10 to 20 in. lbs.).
²New Bearings: 2 to 5 Nzm (15 to 35 in. lbs.).
(12) If rotating torque is high, add shims to de-
crease torque. If rotating torque is low, remove shims
to increase torque.DIFFERENTIAL SHIM PACK MEASUREMENT AND
ADJUSTMENT
(1) Place Master Differential Bearing D-134
(D-348) on the case hubs.
(2) Install a pilot stud at the left side of housing.
Attach Dial Indicator to housing. Load the indicator
plunger against the back of the ring gear (Fig. 55).
Ensure ring and pinion gear teeth are tightly
meshed. Zero the indicator.
Fig. 51 Pinion Seal Installation
Fig. 52 Pinion Yoke Installation
Fig. 53 Tightening Pinion Nut
Fig. 54 Check Pinion Gear Torque
JFRONT SUSPENSION AND AXLE 2 - 43

(3) Insert a small pry bar between the bearing cap
and left side of differential case. Pry the case as far
as possible to right side (Fig. 55). Zero the dial indi-
cator pointer.
(4) Repeat the measurement several times to check
consistency. Record the travel distance.
The measurement above shows shim thick-
ness necessary to eliminate ring gear backlash.
Subtract this thickness from case zero end-play
shim thickness (Fig. 56). The shims must be
placed at the ring gear side between the case
and bearing.
(5) Remove indicator and pilot stud.
(6) Remove the differential case from housing.
(7) Remove the master bearing tools from the dif-
ferential case hubs.
(8) Position the backlash shims (with determined
thickness) on case hub (ring gear side). Install bear-
ing on the hub with Bearing Installer C-3716-A and
Driver Handle C-4171 (Fig. 57).
(9) Position the remaining zero end-play shims on
hub at opposite side of case. Include an additional
0.015 in. (0.38 mm) thick shim on this hub. This will
provide the required differential bearing preload.
(10) Install bearings on hubs with Installer
C-3716-A and Handle C-4171 (Fig. 57).
(11) Match each bearing cup with bearing (origi-
nal). Install the cups on the bearings.
DIFFERENTIAL INSTALLATION
(1) Position Spreader W-129-B with the tool dowel
pins seated in the locating holes (Fig. 58). Install the
holddown clamps and tighten the tool turnbuckle fin-
ger-tight.(2) Install a pilot stud at the left side of the differ-
ential housing. Attach Dial Indicator to housing pilot
stud. Load the indicator plunger against the opposite
side of the housing (Fig. 58) and zero the indicator.
CAUTION: Do not spread over 0.38 mm (0.015 in). If
the housing is over-separated, it could be distorted
or damaged.
Fig. 55 Shim Pack MeasurementFig. 56 Shim Pack Calculations
Fig. 57 Differential Bearing Installation
2 - 44 FRONT SUSPENSION AND AXLEJ

(3) Spread the housing enough to install the case
in the housing. Measure the distance with the dial
indicator (Fig. 58).
(4) Remove the dial indicator.
(5) Install case in the housing. Tap the differential
case to ensure the bearings are fully seated (Fig. 59).
Remove the spreader.
(6) Install the bearing caps at their original loca-
tions (Fig. 60). Tighten the bearing cap bolts to 61
Nzm (45 ft. lbs.) torque.
BACKLASH AND CONTACT PATTERN ANALYSIS
(1) Rotate assembly several revolutions to seat
bearings. Measure backlash at three equally spaced
locations around the perimeter of the ring gear with
a dial indicator (Fig. 61).The ring gear backlash must be within 0.12 -
0.20 mm (0.005 - 0.008 inch). It cannot vary
more than 0.05 mm (0.002 inch) between the
points checked.
If backlash must be adjusted, transfer shims from
one side of carrier to the other side. Adjust the back-
lash accordingly (Fig. 62).DO NOT INCREASE
THE TOTAL SHIM PACK THICKNESS, EXCES-
SIVE BEARING PRELOAD AND DAMAGE WILL
OCCUR.
If the mesh and backlash steps have been followed,
good gear teeth contact patterns should exist.
The ring gear teeth contact patterns will show if
the pinion gear depth is correct. It will also show if
the ring gear backlash has been adjusted correctly.
The backlash must be maintained within the speci-
fied limits until the correct tooth contact patterns are
obtained.
(2) Apply a thin coat of hydrated ferric oxide (yel-
low oxide of iron) to the drive and coast side of the
ring gear teeth.
Fig. 58 Spread Differential Housing
Fig. 59 Differential Installation
Fig. 60 Differential Bearing Cap Reference Letters
Fig. 61 Ring Gear Backlash Measurement
JFRONT SUSPENSION AND AXLE 2 - 45

(3) Rotate the ring gear one complete revolution in
both directions while a load is being applied. Insert a
pry bar between the differential housing and the case
flange to load gears. This will produce a distinct con-
tact patterns on both the drive side and coast side of
the ring gear teeth.(4) Note patterns in compound. Refer to (Fig. 63)
for interpretation of contact patterns and adjust ac-
cordingly.
FINAL ASSEMBLY
(1) Install the axle shafts. Refer to Axle Shaft In-
stallation in this Group.
(2) Scrape the residual sealant from the housing
and cover mating surfaces. Clean the mating surfaces
with mineral spirits. Apply a bead of MOPARtSili-
cone Rubber Sealant on the housing cover (Fig. 64).
Allow the sealant to cure for a few minutes.
Install the housing cover within 5 minutes af-
ter applying the sealant. If not installed the
sealant must be removed and another bead ap-
plied.
(3) Install the cover on the differential with the at-
taching bolts. Install the identification tag. Tighten
the cover bolts with 41 Nzm (30 ft. lbs.) torque.
CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
(4) Refill the differential housing with the specified
quantity of MOPARtHypoid Gear Lubricant.
(5) Install the fill hole plug and tighten to 34 Nzm
(25 ft. lbs.) torque.
Fig. 62 Backlash Shim Adjustment
2 - 46 FRONT SUSPENSION AND AXLEJ

Fig. 63 Gear Tooth Contact Patterns
JFRONT SUSPENSION AND AXLE 2 - 47

Fig. 64 Typical Housing Cover With Sealant
2 - 48 FRONT SUSPENSION AND AXLEJ