10 1/2 Inch Ring Gear

Fig. 11 Pinion Depth shim Selection Chart:

Fig. 12 Side Bearing Preload Adjustment:

1. Inspect head of drive pinion for pinion depth code number. Pinion may be stamped with either plus (+) or minus (-) number, indicating necessary modification of shim thickness to ensure proper engagement.
2. Compare depth code number with number on original pinion and use chart, Fig. 11, to select proper shim thickness for preliminary pinion depth adjustment as follows:
a. Refer to thickness of shims removed during disassembly and add or subtract the value shown in chart.
b. If original pinion, housing and rear bearing is to be reused, install shims of original thickness.
3. Position selected shim on axle housing, ensure that bolt holes are aligned, then install pinion assembly and torque retaining bolts to 65 ft. lbs. in crossing pattern.
4. Place outer races over differential case bearings, mount differential assembly in housing and install bearing caps, and tighten cap bolts snug.
5. Loosen right bearing adjusting nut and tighten left nut using suitable tool, Fig. 12, until ring gear contacts pinion. Do not force gears into contact. Tighten left nut just enough to obtain zero backlash without binding gears.
6. Loosen left adjusting nut approximately two notches, then install adjusting nut lock.
7. Firmly tighten right adjusting nut to force case against left nut, then loosen nut until clearance exists between right nut and bearing race.
8. Tighten right adjusting nut until it just contacts bearing race (zero preload), then tighten nut an additional two slots for used bearings or three slots for new bearings and secure position with locking retainer. At this point differential bearing preload is properly set. If any additional adjustments are required, ensure that preload remains as established. If one adjusting nut is loosened, the other nut must be tightened an equal amount in order to maintain preload.

Fig. 13 Ring Gear & Pinion Backlash Measurement:

Fig. 14 Ring Gear & Pinion Tooth Contact Inspection:

9. Mount suitable dial indicator on housing with plunger contact bearing against ring gear tooth, Fig. 13.
10. Hold pinion and rock ring gear back and forth, reading backlash from dial indicator.
11. Backlash should be .003-.012 inch, with .005-.008 inch the preferred setting. If original ring gear and pinion are used, set backlash to amount measured during disassembly to avoid changing gear contact pattern.
12. If backlash is not within specifications, proceed as follows:
a. If backlash is greater than .012 inch, loosen right adjusting nut one notch and tighten left nut one notch.
b. If backlash is less than .003 inch, loosen left adjusting nut one notch, then tighten right nut 1 notch. Always rotate adjusting nuts equal amounts in opposite directions to maintain differential bearing preload.
c. Recheck backlash after each adjustment and correct as needed.
d. When proper backlash has been obtained, install adjusting nut locks to secure adjustment.
13. Torque side bearing cap bolts to 135 ft. lbs., then check gear tooth contact pattern as follows. Gear tooth contact pattern must be checked to verify the correct relationship between ring gear and pinion in order to ensure that pinion depth is set properly.
a. Ensure that ring gear is clean and free from oil.
b. Apply suitable marking compound to coat drive and coast face of each ring gear tooth.
c. Apply braking force to differential case in order to load gears, then turn pinion to rotate ring gear one full revolution in each direction. If check is made without loading gears, a satisfactory pattern cannot be obtained. Excessive rotation of ring gear is not recommended.
d. Inspect contact pattern on ring gear and correct differential adjustments, if necessary, as shown in Fig. 14.
e. Clean marking compound from gears.
14. Install axle shafts, rear cover and gasket.
15. Install axle assembly in vehicle, then fill with specified lubricant.