Adjustment

For quiet and reliable final drive operation, the following five adjustments must be made correctly:
1. Side bearing preload
2. Pinion gear height
3. Side bearing preload
4. Ring gear-to-pinion backlash. Refer to Specifications.
5. Ring and pinion gear tooth contact pattern

PINION GEAR HEIGHT
1. Make sure all parts are clean and that the bearings are well lubricated.





2. Assemble the pinion gear bearings into the pinion pre-load shim selector tool, J34309.





^ Rear Pinion Bearing - the rear pinion bearing pilot, J34309-8, is used to center the rear pinion bearing only. The rear pinion bearing locking seat, J34309-4, is used to lock the bearing to the assembly.
^ Front Pinion Bearing - make sure the J34309-3, front pinion bearing seat is secured tightly against the J34309-2 gauge anvil. Then turn the front pinion bearing pilot, J34309-5, to secure the bearing in its proper position.





3. Place the pinion preload shim selector tool gauge screw assembly, J34309-1, with the pinion rear bearing inner cone installed, into the final drive housing.





4. Install the J34309-2 gauge anvil with the front pinion bearing into the final drive housing and assemble it to the J34309-1 gauge screw. Make sure that the J34309-16 gauge plate will turn a full 360 degrees, and tighten the two sections by hand to set bearing pre-load.
5. Turn the assembly several times to seat the bearings.





6. Measure the turning torque at the end of the J34309-2 gauge anvil using torque wrench J25765-A.
Turning torque specification: 0.4 - 0.9 Nm (4 - 9 kg-cm, 3.5 - 7.8 inch lbs.)





7. Place the J34309-12 "H233B" pinion height adapter onto the gauge plate and tighten it by hand.

CAUTION: Make sure all machined surfaces are clean.

Pinion Height Adjusting Washer Selection





8. Position the J25269-18 side bearing discs and the arbor into the side bearing bores.





9. Install the bearing caps and torque the bolts.
Specification: 93 - 103 Nm (9.5 - 10.5 kg-m, 69 - 76 ft. lbs.)





10. Select the correct standard pinion height adjusting washer thickness using a standard gauge of 2.5, 3.0, or 3.5 mm (0.098, 0.118, or 0.138 inch) and your J34309-101 feeler gauge. Measure the distance between the J34309-12 "H233B" pinion height adapter and the arbor.





11. Write down your exact total measurement.





12. Correct the pinion height washer size by referring to the "pinion head height number".
There are two numbers painted on the pinion gear. The first one refers to the pinion and ring gear as a matched set and should be the same as the number on the ring gear. The second number is the "pinion head height number", and it refers to the ideal pinion height from standard for the quietest operation.





Use the chart to determine the correct pinion height washer. Refer to Application and ID.
13. Select the correct pinion height washer. Drive pinion height adjustment: Refer to Application and ID.





14. Remove the J34309 pinion preload shim selector tool from the final drive housing and disassemble to retrieve the pinion bearings.

TOOTH CONTACT
Gear tooth contact pattern check is necessary to verify correct relationship between ring gear and drive pinion.
Hypoid gear sets which are not positioned properly in relation to one another may be noisy, or have short life or both. With a pattern check, the most desirable contact for low noise level and long life can be assured.
1. Thoroughly clean ring gear and drive pinion teeth.





2. Sparingly apply a mixture of powdered ferric oxide and oil or equivalent to 3 or 4 teeth of ring gear drive side.





3. Hold companion flange steady by hand and rotate the ring gear in both directions.





Tooth Contact Area