Jeep Cherokee (XJ): Cleaning and inspection. Adjustments. Specifications

Axle components

Wash differential components with cleaning solvent and dry with compressed air. Do not steam clean the differential components.

Wash bearings with solvent and towel dry, or dry with compressed air. DO NOT spin bearings with compressed air. Cup and bearing must be replaced as matched sets only.

Clean axle shaft tubes and oil channels in housing.

Inspect for;

•  Smooth appearance with no broken/dented surfaces on the bearing rollers or the roller contact surfaces.
•  Bearing cups must not be distorted or cracked.
•  Machined surfaces should be smooth and without 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.

Trac-lok

Clean all components in cleaning solvent. Dry components with compressed air. Inspect clutch pack plates for wear, scoring or damage. Replace both clutch packs if any one component in either pack is damaged. Inspect side gears and pinions. Replace any gear that is worn, cracked, chipped or damaged.

Inspect differential case and pinion shaft. Replace if worn or damaged.

PRESOAK PLATES AND DISC

Plates and discs with fiber coating (no grooves or lines) must be presoaked in Friction Modifier before assembly. Soak plates and discs for a minimum of 20 minutes.

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.

64). 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 center line of the ring gear to the back face of the pinion is 96.850 mm (3.813 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. 64 Pinion Gear ID Numbers

1 - PRODUCTION NUMBERS
2 - DRIVE PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER (SAME AS RING GEAR NUMBER)

Compensation for pinion depth variance is achieved with select shims. The shims are placed under the inner pinion bearing cone (Fig. 65).

If a new gear set is being installed, note the depth variance etched into both the original and replacement pinion gear. Add or subtract the thickness of the original depth shims to compensate for the difference in the depth variances. Refer to the Depth Variance charts.

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 represent thousands of an inch deviation from the standard.

If the number is negative, add that value to the required thickness of the depth shim(s). If the number 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.

Fig. 65 Shim Locations

1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING SHIM-PINION GEAR SIDE
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM-RING GEAR SIDE
5 - COLLAPSIBLE SPACER

PINION GEAR DEPTH VARIANCE

PINION DEPTH MEASUREMENT AND ADJUSTMENT

Measurements are taken with pinion cups and pinion bearings installed in housing. Take measurements with a Pinion Gauge Set, Pinion Block 6735, Arbor Discs 6732, and Dial Indicator C-3339 (Fig.

66).

(1) Assemble Pinion Height Block 6739, Pinion Block 6735, and rear pinion bearing onto Screw 6741 (Fig. 66).

(2) Insert assembled height gauge components, rear bearing and screw into axle housing through pinion bearing cups (Fig. 67).

(3) Install front pinion bearing and Cone 6740 hand tight (Fig. 66).

(4) Place Arbor Disc 6732 on Arbor D-115-3 in position in axle housing side bearing cradles (Fig. 68).

Install differential bearing caps on Arbor Discs and tighten cap bolts. Refer to the Torque Specifications in this section.

NOTE: Arbor Discs 6732 have different step diameters 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.

Fig. 66 Pinion Gear Depth Gauge Tools-Typical

1 - DIAL INDICATOR
2 - ARBOR
3 - PINION HEIGHT BLOCK
4 - CONE
5 - SCREW
6 - PINION BLOCK
7 - SCOOTER BLOCK
8 - ARBOR DISC

Fig. 67 Pinion Height Block-Typical

1 - PINION BLOCK
2 - PINION HEIGHT BLOCK

1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCK

(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 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.

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. 69). 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. Continue 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 reading plus the drive pinion gear depth variance number etched in the face of the pinion gear (Fig. 64) using the opposite sign on the variance number. For example, if the depth variance is -2, add +0.002 in. to the dial indicator reading.

(10) Remove the pinion depth gauge components from the axle housing

Fig. 69 Pinion Gear Depth Measurement-Typical

1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR

Differential bearing preload and gear backlash

Differential side bearing preload and gear backlash is achieved by selective shims inserted between the bearing cup and the axle housing. The proper shim thickness can be determined using slip-fit dummy bearings D-348 in place of the differential side bearings and a dial indicator C-3339. Before proceeding with the differential bearing preload and gear backlash measurements, measure the pinion gear depth and prepare the pinion gear for installation. Establishing proper pinion gear depth is essential to establishing gear backlash and tooth contact 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 measured. The overall shim thickness is the total of the dial indicator reading, starting point shim thickness, 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 differential (Fig. 70).

SHIM SELECTION

NOTE: It is difficult to salvage the differential side bearings during the removal procedure. Install replacement bearings if necessary.

(1) Remove side bearings from differential case.

(2) Install ring gear, if necessary, on differential case and tighten bolts to specification.

Fig. 70 Axle Adjustment Shim Locations

1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING SHIM-PINION GEAR SIDE
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM-RING GEAR SIDE
5 - COLLAPSIBLE SPACER

(3) Install dummy side bearings D-348 on differential case.

(4) Install differential case in axle housing.

(5) Insert Dummy Shims 8107 (0.118 in. (3.0 mm)) starting point shims between the dummy bearing and the axle housing (Fig. 71).

Fig. 71 Insert Starting Point Shims

1 - SPECIAL TOOL 8107
2 - AXLE HOUSING
3 - DIFFERENTIAL CASE
4 - SPECIAL TOOL D-348

(6) Install the marked bearing caps in their correct positions. Install and snug the bolts.

(7) Using a dead-blow type mallet, seat the differential dummy bearings to each side of the axle housing (Fig. 72) and (Fig. 73).

Fig. 72 Seat Pinion Gear Dummy Side Bearing

1 - MALLET
2 - AXLE HOUSING
3 - DIFFERENTIAL CASE

Fig. 73 Seat Ring Gear Side Dummy Bearing

1 - AXLE HOUSING
2 - MALLET
3 - DIFFERENTIAL CASE

(8) Thread guide stud C-3288-B into rear cover bolt hole below ring gear (Fig. 74).

(9) Attach dial indicator C-3339 to guide stud.

Position the dial indicator plunger on a flat surface on a ring gear bolt head (Fig. 74).

(10) Push firmly and hold differential case to pinion gear side of axle housing (Fig. 75).

(11) Zero dial indicator face to pointer.

Fig. 74 Differential Side play Measurement

1 - DIFFERENTIAL CASE
2 - AXLE HOUSING
3 - SPECIAL TOOL C-3288-B
4 - SPECIAL TOOL C-3339

(12) Push firmly and hold differential case to ring gear side of the axle housing (Fig. 76).

(13) Record dial indicator reading.

Fig. 75 Hold Differential Case and Zero Dial Indicator

1 - FORCE DIFFERENTIAL CASE TO PINION GEAR SIDE
2 - SPECIAL TOOL C-3288-B
3 - SPECIAL TOOL C-3339
4 - ZERO DIAL INDICATOR FACE

Fig. 76 Hold Differential Case and Read Dial Indicator

1 - READ DIAL INDICATOR
2 - FORCE DIFFERENTIAL CASE TO RING GEAR SIDE
3 - AXLE HOUSING

(14) Add the dial indicator reading to the starting point shim thickness to determine total shim thickness to achieve zero differential end play.

(15) Add 0.008 in. (0.2 mm) to the zero end play total. This new total represents the thickness of shims to compress, or preload the new bearings when the differential is installed.

(16) Rotate dial indicator out of the way on guide stud.

(17) Remove differential case, dummy bearings, and starting point shims from axle housing.

(18) Install pinion gear in axle housing. Install the yoke and establish the correct pinion rotating torque.

(19) Install differential case and dummy bearings in axle housing (without shims) and tighten retaining cap bolts.

(20) Position the dial indicator plunger on a flat surface between the ring gear bolt heads (Fig. 74).

(21) Push and hold differential case toward pinion gear.

(22) Zero dial indicator face to pointer.

(23) Push and hold differential case to ring gear side of the axle housing.

(24) Record dial indicator reading.

(25) Subtract 0.002 in. (0.05 mm) from the dial indicator reading to compensate for backlash between ring and pinion gears. This total is the thickness of shim required to achieve proper backlash.

(26) Subtract the backlash shim thickness from the total preload shim thickness. The remainder is the shim thickness required on the pinion side of the axle housing.

(27) Rotate dial indicator out of the way on guide stud.

(28) Remove differential case and dummy bearings from axle housing.

(29) Install new side bearing cones and cups on differential case.

(30) Install spreader W-129-B, utilizing some components of Adapter Set 6987, on axle housing and spread axle opening enough to receive differential case.

(31) Place side bearing shims in axle housing against axle tubes.

(32) Install differential case in axle housing.

(33) Rotate the differential case several times to seat the side bearings.

(34) Position the indicator plunger against a ring gear tooth (Fig. 77).

(35) Push and hold ring gear upward while not allowing the pinion gear to rotate.

(36) Zero dial indicator face to pointer.

(37) Push and hold ring gear downward while not allowing the pinion gear to rotate. Dial indicator reading should be between 0.12 mm (0.005 in.) and 0.20 mm (0.008 in.). If backlash is not within specifications transfer the necessary amount of shim thickness from one side of the differential housing to the other (Fig. 78).

(38) Verify differential case and ring gear runout by measuring ring to pinion gear backlash at eight locations around the ring gear. Readings should not vary more than 0.05 mm (0.002 in.). If readings vary more than specified, the ring gear or the differential case is defective.

After the proper backlash is achieved, perform the Gear Contact Pattern Analysis procedure.

Fig. 77 Ring Gear Backlash Measurement

1 - DIAL INDICATOR

Gear contact pattern analysis

The ring gear and pinion teeth contact patterns will show if the pinion depth is correct in the axle housing. It will also show if the ring gear backlash has been adjusted correctly. The backlash can be adjusted within specifications to achieve desired tooth contact patterns.

(1) Apply a thin coat of hydrated ferric oxide, or equivalent, to the drive and coast side of the ring gear teeth.

Fig. 78 Backlash Shim Adjustment

(2) Wrap, twist, and hold a shop towel around the pinion yoke to increase the turning resistance of the pinion. This will provide a more distinct contact pattern.

(3) Using a boxed end wrench on a ring gear bolt, Rotate the differential case one complete revolution in both directions while a load is being applied from shop towel.

The areas on the ring gear teeth with the greatest degree of contact against the pinion teeth will squeegee the compound to the areas with the least amount of contact. Note and compare patterns on the ring gear teeth to Gear Tooth Contact Patterns chart (Fig.

79) and adjust pinion depth and gear backlash as necessary.

Fig. 79 Gear Tooth Contact Patterns

194 RBI axle

DESCRIPTION SPECIFICATION

Axle Type . . . . . . . . . . . . . . . Semi-Floating Hypoid
Lubricant . . . . . . . . SAE Thermally Stable 80W-90
Lubricant Trailer Tow . . . . . . . Synthetic 75W-140
Lube Capacity . . . . . . . . . . . . . . . 1.66 L (3.50 pts.)
Friction Modifier . . . . . . . . . . . . . 0.12 L (3.50 ozs.)
Axle Ratios . . . . . . . . . . . . . . . . . . . 3.07, 3.55, 3.73
Differential Bearing Preload . . . 0.1 mm (0.008 in.)
Differential Side Gear Clearance . . . . . . 0-0.15 mm (0-0.006 in.)
Ring Gear Diameter . . . . . . . . . 19.2 cm (7.562 in.)
Ring Gear Backlash . . 0-0.15 mm (0.005-0.008 in.)
Pinion Std. Depth . . . . . . . . . . 96.85 mm (3.813 in.)
Pinion Bearing Preload-Original Bearings . . . . . . . . . . . . 1-2 N·m (10-20 in. lbs.)
Pinion Bearing Preload-New Bearings . . 1.5-4 N·m (15-35 in. lbs.)

194 RBI axle

DESCRIPTION TORQUE

Bolt, Diff. Cover . . . . . . . . . . . . 41 N·m (30 ft. lbs.)
Bolt, Bearing Cap . . . . . . . . . . . 77 N·m (57 ft. lbs.)
Nut, Pinion . . . . . . . 271-474 N·m (200-350 ft. lbs.)
Screw, Pinion Mate Shaft Lock . . . . . . . . 16.25 N·m (12 ft. lbs.)
Bolt, Ring Gear . . . . . . 95-122 N·m (70-90 ft. lbs.)
Bolt, RWAL/ABS Sensor . . . . . . . 8 N·m (70 in. lbs.)