Differential Drive Pinion Gear Depth

Standard Rear Axle Assembly:

Rear Axle Assembly With Traction Control (Acceleration Slip Regulation):

^ Tools Required:
- J 8001 Dial Indicator Set
- J 23597-1 Arbor
- J 23597-11 Gage Plate
- J 21777-40 Rear Pilot Washer
- J 21777-42 Front Pilot Washer
- J 21777-43 Stud Assembly-Bolt
- J 21777-45 Side Bearing Discs

Differential drive pinion gear depth is measured with a pinion setting gage. The gage provides a "nominal" or "zero" pinion as a gauging reference.

DISASSEMBLE
- Differential case.

REMOVE OR DISCONNECT
- Differential drive pinion gear inner bearing (18).

Clean
1. All parts of gage.
2. Differential bearing bore.
3. Inner and outer drive pinion gear bearing cups.
4. Lubricate inner and outer drive pinion gear bearings (18 and 7) with axle lubricant or SAE 80W-90 GL-5 gear lubricant or equivalent.

INSTALL OR CONNECT

NOTICE: Always use the correct fastener in the correct location. When you replace a fastener, use ONLY the exact part number for that application. The Manufacturer will call out those fasteners that require a replacement after removal. The Manufacturer will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHER WISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on the threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems.

1. J 21777-40 through J 21777-43.
2. J 23597-11.
3. J 777-42 and nut in rear axle housing (16).

Tighten
- Differential drive pinion gear setting gage nut to 2.3 Nm (20 inch lbs.).

4. Rotate J 23597-11 to seat inner and outer drive pinion gear bearings (18 and 7).
5. Mount J 8001 on J 23597-1 and preload indicator against plunger about 1.27 mm (0.050 inch).
6. J 21777-45 on J 23597-1 and position unit in rear axle housing (16).
7. Carrier bearing caps (22) and bearing cap bolts/screws (26).

Tighten
- Differential carrier bearing cap bolt/screws (26) to 75 Nm (55 ft. lbs.).

Measure
- Differential drive pinion gear depth.

a. Rotate J 23597-1 slowly back and forth until J 8001 reads the greatest deflection (the point where the needled changes direction). At that point, set J 8001 to zero.
b. Repeat rocking action to verify zero setting.
c. After zero setting is obtained, rotate J 23597-1 just until plunger no longer touches J 23597-11. This provides the gage reference of a "zero" or "nominal" drive pinion gear (23).
d. Record J 8001 reading at pointer position. This indicates the proper drive pinion gear shim to use. Example: if pointer moved counterclockwise 1.70 mm (0.067 inch) to a dial reading of 0.84 mm (0.033 inch), this indicates a shim thickness of 0.84 mm (0.033 inch).
e. Required drive pinion gear shim thickness is EQUAL to J 8001 reading.
f. Drive pinion gear shims are available in 0.03 mm to 0.94 mm (0.001 inch to 0.037 inch). Shim thickness is etched on the flat surface for easy identification.

INSTALL OR CONNECT

1. Loosen J 21777-43 and remove special tools and inner and outer drive pinion gear bearings (18 and 7) from rear axle housing (16).
2. Correct drive pinion gear shim (19) on drive pinion gear (23).

Important:
- Proper drive pinion gear depth setting is a two-step procedure.
a. The set-up dimension arrived at using J 8001 is to be considered a starting point.
b. A ring gear tooth pattern check is necessary to fine tune the drive pinion gear depth and may indicate additional drive pinion gear shim changes to the drive pinion gear. Refer to "TOOTH CONTACT PATTERN TEST."
- Both procedures must be performed to ensure proper rear axle performance.

3. Drive pinion gear inner and outer bearing.

ASSEMBLE
- Differential case.

Measure
- Preload of the total at the drive pinion gear nut (1). With new inner and outer drive pinion gear bearings (18 and 7), preload is 3.6 Nm to 6.2 Nm (32 inch lbs. to 55 inch lbs.) rotating torque with a new drive pinion gear seal (6). With used inner and outer drive pinion gear bearing (18 and 7), preload is 1.8 Nm to 3.1 Nm (16 inch lbs. to 28 inch lbs.) rotating torque with a new drive pinion gear seal (6).