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Home >> GMC Truck >> 1997 >> C 2500 Truck 2WD V8-5.7L VIN R >> Repair and Diagnosis >> Transmission and Drivetrain >> Differential Assembly >> Service and Repair >> Unit Repair >> Rear Drive Axle >> Full-Floating Axle Dana Model 80, 11 Inch Ring Gear >> Assembly of the Rear Axle >> Pinion Depth Adjustment

Pinion Depth Adjustment

- Tools Required:
- J 39704 Dial Indicator
- J 39702 Arbor
- J 39701 Master Discs
- J 41690 Master Pinion Block
- J 41689 Pinion Height Block
- J 41691 Adapter Cone
- J 41692 Threaded Rod
- J 39708 Handle
- J 39707 Cup Installer (Inner Pinion Bearing Cup)
- J 8092 Driver Handle
- J 7818 Rear Pinion Bearing Cup Installer

NOTICE: You may use the older style gage set if you already have them. The new style gages use the bearings as part of the gage system, walls the older style uses a master block that acts as a master bearing.

1. Clean the carrier bores and all tools. The pinion bore must be free of nicks and dirt.
2. Drive the inner bearing cup into the axle assembly using J 39708 and J 39707. The cup must be seated.





3. Drive the outer bearing cup into the axle assembly using J 7818 and J 8092.
4. Assemble inner bearing cone into cup.





5. Assemble master pinion block J 41690, pinion height block J 41689 into carrier housing using adapter cone J 41691 and screw J 41692. The outer bearing cone will be used with the adapter cone and should be assembled at this time.
6. Hand tighten the cone until all end-play is removed from gage assembly.





7. Place J 39704 onto the height block.
- Place the gage on the upper Step of the height block. Apply pressure to the gage block, pushing down on the height block. While applying pressure, set the dial indicator at zero.





8. Slide the gage over the arbor.
9. Record the reading at the point of greatest deflection (when the dial indicator needle is centered between movement to the left and right).
A. This reading indicates the amount of shims needed for a nominal pinion setting. The pinion marking may change the pinion depth by adding or deleting shims from the nominal pinion setting.
B. A positive (+) pinion marking indicates that the distance between the ring gear centerline and the pinion head must increase by the number of thousandths marked on the pinion. This means that the shim pack will decrease by the same number of thousandths.
C. A negative (-) pinion marking indicates that the distance between the ring gear centerline and the pinion head must decrease by the number of thousandths marked on the pinion. This means that the shim pack will increase by the same number of thousandths.
D. A pinion etched zero (0) will use the nominal setting determined by this procedure.
10. After making the measurement, remove the gage tools and the inner pinion bearing cone and cup.
11. Measure each shim separately with a micrometer and add the dimensions together to obtain the total shim pack thickness. If a baffle or slinger is used, these also must be measured and included in the shim pack.
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