8.6 Inch Axle
Pinion Depth Adjustment (8.6 Inch Axle)Tools Required
^ J34925 Pinion Setting Gage and Components
^ J8001 Dial Indicator Set
Important: Make sure all of the tools, the differential side bearing bores, and the pinion bearing cups are clean before proceeding.
1. Lubricate the pinion bearings with axle lubricant.
2. Install the pinion bearings into the axle housing.
3. Assemble the J21777-35 (1), the J21777-43 (2), the J21777-42 (3), and the J21777-29 (4) into the axle housing as shown.
4. While holding the J21777-43 stationary, install an inch-pound torque wrench on the nut of the J21777-43 and tighten the nut until a rotating torque of 1.7 - 3.4 Nm (15 - 30 inch lbs.) for new bearings or 1.1 - 2.3 Nm (10 - 20 inch lbs.) for used bearings is obtained
Rotate the assembly several times in both directions in order to seat the pinion bearings.
5. Check the rotating torque of the assembly. If the torque is less than 1.7 Nm (15 inch lbs.) for new bearings or 1.1 Nm (10 inch lbs.) for used bearings, continue to tighten the nut on the J21777-43 until a rotating torque of 1.7 - 3.4 Nm (15 - 30 inch lbs.) for new bearings or 1.1 - 2.3 Nm (10 - 20 inch lbs.) for used bearings is obtained.
6. Assemble the J21777-45 (1, 2) to the J21777-1 (3) into the differential side bearing bore of the axle housing as shown.
7. Install the differential bearing caps.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
8. Install the differential bearing cap bolts
Tighten the differential bearing cap bolts to 75 Nm (55 ft. lbs.).
9. Rotate the J21777-1 within the J21777-45. The J21777-1 must rotate back and forth freely within the discs. If the J21777-1 does not rotate freely, disassemble the components, inspect for proper seating and/or mix-aligned components and re-assemble.
10. Align the plunger of the J21777-1 (1) to the 8.5 in gage block setting of the J21777-29 (2).
11. Install the J8001 to the J21777-1 as follows:
11.1. Loosely clamp the J8001 onto the stem on the J21777-1.
11.2. Place the contact pad of the J8001 onto the mounting post of the J21777-1.
11.3. With the contact pad of the J8001 touching the mounting post of the J21777-1, loosen the lock nut on the J8001 and push down on the J8001 until the needle the J8001 has turned 3/4 of a turn clockwise.
11.4. Tighten the clamp on the J8001 finger tight.
12. Move the plunger of the J21777-1 back and forth until the needle of the J8001 indicates the greatest deflection.
The deflection is the point where the needle changes direction.
13. At the greatest point of deflection, move the housing of the J8001 until the needle indicates zero.
14. Move the plunger of the J21777-1 back and forth again to verify the zero setting. Adjust the housing of the J8001 as necessary to set the needle to zero.
15. Rotate the plunger of the J21777-1 away from the J21777-29.
16. The value indicated on the J8001 is the thickness of the shim needed in order to set the depth of the pinion.
17. Select the shim that indicates the proper thickness. Measure the shim with a micrometer in order to verify that the thickness is correct.
18. Remove the pinion depth setting tools.
19. Remove the pinion bearings.
20. Install the pinion shim between the pinion gear and the inner pinion bearing.