Pinion Depth Adjustment (G86 9.76 Inch Axle)

Special Tools DT-21777-B Pinion Setting Gauge and Components DT-51173 Pinion Shim Selection Adapter Kit DT-52901 Main Bearing Cap Bridge Assembly Equivalent regional tools: Special Tools Procedure

Note

Make sure all of the tools, the differential side bearing bores, and the pinion bearing cups are clean before proceeding.

1. Using the proper axle lubricant, lubricant the differential pinion bearings. Adhesives, Fluids, Lubricants, and Sealers
2. Install the differential pinion bearings into the axle housing.

Pinion Depth Adjustment (G86 9.76 Inch Axle) — figure 1

3. Install the DT-51173-3 Rear Bearing Pilot (2), DT-21777-43 Stud Assembly Bolt (3), DT- 51173-2 Front Bearing Pilot (4), and the DT-51173-1 Gauge Block (1).

Note

Hold the DT-21777-43 Stud Assembly Bolt stationary while turning the torque wrench. Rotate the assembly several times in both directions in order to seat the pinion bearings.

4. Using an inch pound torque wrench and the DT-21777-43 Stud Assembly Bolt (3), tighten the nut until the specified rotating torque for the pinion bearings is obtained, refer to Axle Preload and Backlash Specifications.

Pinion Depth Adjustment (G86 9.76 Inch Axle) — figure 2

5. Install the DT-21777-1 Arbor Assembly (3) with the DT-21777-86 Side Bearing Discs (1) and (2) into the differential carrier bores.

Pinion Depth Adjustment (G86 9.76 Inch Axle) — figure 3

6. Install the DT-52901 Main Bearing Cap Bridge Assembly (1).

Caution

Refer to Fastener Caution.

7. Install and tighten the 4 rear axle housing cover bolts to hold DT-52901 Main Bearing Cap Bridge Assembly. Fastener Specifications
8. Rotate the DT-21777-1 Arbor Assembly (3) within the DT-21777-86 Side Bearing Discs (1) and (2). The DT-21777-1 Arbor Assembly (3) must rotate back and forth freely within the discs. If the DT-21777-1 Arbor Assembly (3) does not rotate freely, disassemble the components, inspect for proper seating and/or mis-aligned components and re-assemble.
9. Adjust the arbor of the DT-21777-1 Arbor Assembly (3) to touch the top of the DT-51173-1 Gauge Block (4).
10. Install the J-8001 Dial Indicator Set (2) to the DT-21777-1 Arbor Assembly (3) as follows: 10.1. Loosely clamp the J-8001 Dial Indicator Set onto the stem on the DT-21777-1 Arbor Assembly. 10.2. Place the contact pad of the J-8001 Dial Indicator Set onto the mounting post of the DT- 21777-1 Arbor Assembly. 10.3. With the contact pad of the J-8001 Dial Indicator Set touching the mounting post of the DT-21777-1 Arbor Assembly, loosen the lock nut on the J-8001 Dial Indicator Set and push down on the J–8001 Dial Indicator Set until the needle of the J-8001 Dial Indicator Set has turned approximately 3/4 of a turn clockwise. 10.4. Tighten the clamp on the J-8001 Dial Indicator Set indicator finger tight.

Note

The deflection is the point where the needle changes direction.

11. Rotate the DT-21777-1 Arbor Assembly (3) back and forth until the needle of the J-8001 Dial Indicator Set indicates the greatest deflection.
12. At the greatest point of deflection, adjust the housing of the J-8001 Dial Indicator Set as necessary to set the needle to zero.
13. Rotate the plunger of the DT-21777-1 Arbor Assembly (3) away from the DT-51173-1 Gauge Block (4).
14. The value indicated on the J-8001 Dial Indicator Set, when the DT-21777-1 Arbor Assembly  (3) is rotated away from the DT-51173-1 Gauge Block (4), is the thickness of the shim needed in order to set the depth of the pinion. Record the measurement.
15. Select the shim that indicates the proper thickness. Measure the shim with a micrometer in order to verify that the thickness is correct.
16. Remove the pinion depth setting tools.
17. Remove the pinion bearings.
18. Return to the previous procedure and continue from appropriate step which linked to this procedure.