Assembly & Adjustment
Fig. 4 Pinion depth variance numbers:
Fig. 5 Pinion depth variance chart:
DRIVE PINION INSTALLATION & DEPTH ADJUSTMENT
The standard pinion depth setting is 2.095 inch.
1. Measure thickness of pinion depth shim removed during disassembly.
2. Record pinion depth variance numbers etched on old and new pinion gears. The numbers etched on ring gear and the first set of numbers etched on drive pinion must match to ensure that gears are a matched set. The second number on the drive pinion preceded by a plus or minus sign is the pinion depth variance. The plus or minus signs and number denotes, in thousands of an inch, the amount the gear varied from standard setting.
3. Refer to the chart to determine amount, in thousands, to be added or subtracted from original depth shim to arrive at pinion height. The pinion height arrived at is not the final shim thickness. An actual pinion depth measurement must be performed to determine final shim thickness.
4. Install rear bearing on pinion gear with large diameter of bearing cage facing pinion head. Press bearing against rear face of pinion head.
5. Clean axle housing and pinion bores carefully to ensure proper seating of components, then install pinion depth shim, as determined above, in housing bearing cup bore. Ensure shim is centered in bore. If shim is chamfered on one side, ensure chamfered side faces bottom of bearing cup bore.
6. Using tools J-8092 and J-8608, install rear bearing cup.
7. Using tools J-8092 and J-8611-01, install front bearing cup.
8. Install pinion gear in rear bearing cup, then pinion front bearing and axle yoke. Do not install oil seal or collapsible spacer at this time.
9. Install used pinion nut on pinion shaft. Tighten nut enough to remove end play.
10. Assemble gauge arbor tool J-5223-4 and discs J-6381-2, then install in differential bearing cup bores. Ensure discs are firmly seated in cup bores, then install differential bearing caps and bolts and tighten securely.
11. Position gauge block J-5223-20 on pinion gear raised rear face. To avoid false readings, do not allow anvil to contact pinion gear at any point.
12. Mount gauge tool clamp strap and holding screw tool J-5223-24, then using axle housing cover bolt, mount tool on axle housing cover flange.
13. Extend holding screw until it bears firmly against gauge block to prevent block from moving.
14. Loosen gauge block thumbscrews and release plunger. Allow plunger to contact gauge arbor at center of arbor shaft. Tighten thumbscrews to lock plunger in position. Do not disturb plunger setting. Remove bolt and clamp from axle housing.
15. Remove gauge block, then using suitable three inch micrometer, measure distance from end of anvil to end of plunger. This measurement represents pinion measured depth and is to be recorded for later use. If measurement recorded above equals pinion standard pinion depth setting of 2.095 inch, the installed shim thickness is correct and no further adjustment is required.
16. Remove bearing cap bolts and caps, then the arbor tool assembly.
17. Remove pinion nut, yoke, pinion gear and front bearing, then the rear bearing cup and depth shim from axle housing.
18. Measure thickness of depth shim removed in previous step, then add this measurement to measurement obtained in step 15. From this total, subtract desired pinion depth. The result represents shim thickness required to adjust pinion depth. Desired pinion depth is pinion standard depth setting of 2.095 inch, plus or minus depth variance.
19. Install proper thickness shim in housing bearing cup bore, then the rear bearing cup. If one side of shim is chamfered, install shim so that chamfered side faces bottom of bearing cup bore.
20. Install pinion gear, collapsible spacer and front bearing.
21. Using installer J-22661, install pinion oil seal. Install axle yoke and pinion nut. While rotating pinion shaft, tighten nut only enough to remove bearing endplay. Continue tightening nut in small increments to collapse spacer and preload bearings. When a very small increase in pinion turning effort is noted, stop tightening pinion nut.
22. Using suitable inch lbs. torque wrench, measure pinion rotational torque. The rotating torque must be 15---25 inch lbs. Do not exceed to specified preload torque. Do not loosen pinion nut if preload torque is exceeded. If preload torque is exceeded, remove pinion nut, yoke, oil seal and collapsible spacer. Replace collapsible spacer and oil seal with new ones and repeat procedure.
DIFFERENTIAL INSTALLATION & ADJUSTMENT
1. Using driver handle J-8592 and installer J-21002, install differential bearings.
2. Install side gear thrust washers. If clearance measured during disassembly exceeded 0.007 inch, replace thrust washers.
3. Install side gears and thrust washers into differential case.
4. Install thrust washers on differential pinions. To make installation easier, mate washer lips with shaft bores in pinions.
5. Install assembled pinions. Mesh pinion with side gears so pinion shaft bores are aligned.
6. Recheck side gear-to-case clearance. If measurement exceeds 0.007 inch and thrust washers have already been replaced, replace side gears.
7. Rotate side gears until pinion shaft bores are aligned with case shaft bore. Install thrust block. Align thrust block bore with case pinion shaft bore.
8. Install differential pinion shaft. Ensure lockpin bores in pinion shaft and case are aligned, then install lockpin.
9. Position differential bearing cups over differential bearings, then place differential case in axle housing.
10. Install 0.142 inch shims on either side of case between bearing cups and axle housing, then install the bearing caps and bolts. Finger tighten bolts.
11. Mount suitable dial indicator to axle housing with stylus contacting ring gear mounting surface.
12. Using a suitable pry tool inserted between shims and housing, pry case assembly to one side and zero dial indicator. Pry case assembly to the opposite side and note dial indicator reading. Do not attempt to read or zero indicator while prying case assembly. The dial indicator reading is the amount necessary to provide differential case zero preload and zero endplay. Repeat procedure to insure accuracy.
13. Install equal thickness shims on either end of case as necessary to adjust endplay. When bearing endplay is eliminated, a slight bearing drag will be noted.
14. Install bearing caps and bolts. Torque bolts to 57 ft-lbs.
15. Mount suitable dial indicator to axle housing with stylus contacting ring gear mounting surface, then rotate case and check ring gear mounting surface for runout. If runout exceeds 0.002 inch, replace differential case.
16. Remove bearing cap bolts, caps and differential assembly. Retain endplay shims for reassembly.
17. Install ring gear on case assembly. Install mounting bolts and tighten alternately and evenly to seat ring gear. Torque bolts to 52 ft-lbs.
18. Install differential assembly, previously selected bearing endplay shims, bearing caps and bearing cap bolts. Torque cap bolts to 57 ft-lbs.
19. Mount dial indicator J-8001 to axle housing with stylus contacting a drive side ring gear tooth at a right angle to tooth. Move ring gear forward and backwards while noting backlash registered on dial indicator. The backlash should be 0.005---0.009 inch with 0.008 inch desired.
20. If backlash is not within specifications, proceed as follows:
a. To increase backlash, install a thinner shim at ring gear side of case and increase shim a like amount at other side of case. Do not change total thickness of the shims.
b. To decrease backlash, install a thicker shim at ring gear side of case and decrease the shim a like amount at other side of case. Do not change total thickness of the shims.
21. Remove differential assembly, then reinstall with shims determined above plus 0.004 inch shim added to each side to preload differential. Tipping the bearing cups slightly will ease entry of cups into bores. Keep differential assembly square in the housing and push it in as far as possible. Tap outer edge of bearing cups with rawhide mallet until differential assembly is seated in axle housing.
22. Install bearing caps, aligning reference marks made during disassembly, then the cap bolts. Torque cap bolts to 57 ft-lbs. Recheck backlash and correct as necessary.
23. Install axle housing cover, then the propeller shaft, rear wheels, brake drums, hubs, axle shafts, oil seals and endplay shims as outlined in "Rear Axle, Propeller Shaft & Brakes" section.
24. Fill axle housing with three pints gear lubricant, then lower vehicle and road test.