Front Drive Axle
Fig. 4 Pinion depth variance numbers:
DRIVE PINION INSTALLATION & DEPTH ADJUSTMENT
The standard pinion depth setting is 2.250 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 the standard setting.
Fig. 5 Pinion depth variance chart:
3. Refer to the chart to determine the 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. Using driver handle J-7079-02 and installer J-25101, install pinion front cup in axle housing bore.
5. Install selected shim in rear bearing bore of housing. Ensure shim is centered in cup bore. If shim is chamfered, chamfer must face housing bore, not towards drive pinion head.
6. Using tools called for in step 4, install rear bearing cup in housing bore.
7. Install oil slinger on pinion gear. Ensure slinger is seated against pinion head before proceeding to step 8.
8. Using bearing installer sleeve J-5590, install rear bearing on drive pinion, then install pinion gear in axle housing.
9. Install pinion front bearing, yoke, washer and old pinion nut. Tighten pinion nut enough to remove endplay and provide 10---15 inch lbs. of drag torque when pinion is rotated. Do not install pinion seal, dust cap or new pinion nut at this time.
10. Assemble gauge arbor tool J-5223-4 and discs J-5223-26, 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. Remove standard plunger from gauge block tool J-5223-20 and install plunger tool J-5223-27.
12. Compress plunger, then tighten gauge block thumbscrews securely. Install gauge block tool in such a way that plunger is directly under arbor tool installed in step 10. Ensure flat surface on anvil side of block is seated on end face of pinion. To avoid false readings, do not allow anvil to contact pinion gear at any point.
13. Assemble bolt J-5223-29 and clamp J-5223-24, then using axle housing cover bolt, mount tools on axle housing cover flange.
14. Extend clamp bolt until pressed against gauge block. Align gauge block pointer with center of gauge arbor, then tighten clamp bolt until it is pressed against block with enough force to prevent block from moving.
15. Loosen gauge block thumbscrews and release plunger. When plunger contacts arbor tool, tighten thumbscrews to lock plunger in position. Do not disturb plunger setting. Remove bolt and clamp from axle housing.
16. 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 2.250 inch, the installed shim thickness is correct and no further adjustment is required.
17. Remove bearing cap bolts and caps, then the arbor tool assembly.
18. Remove pinion nut, pinion gear, rear bearing cup and depth shim from axle housing.
19. Measure thickness of depth shim removed in previous step, then add this measurement to measurement obtained in step 16. 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 2.250 inch, plus or minus depth variance.
20. Install proper thickness shim in housing bearing cup bore, then the rear bearing cup.
21. Install pinion bearing preload shims on pinion shaft, then install pinion gear, front bearing, oil slinger, yoke, washers and old pinion nut. Torque pinion nut to 260 ft-lbs.
22. Using suitable inch lbs. torque wrench, measure pinion rotational torque. The rotating torque should be 20---40 inch lbs. with new bearings or 10---20 inch lbs. with used bearings. Add preload as necessary to bring preload within specifications.
23. Remove pinion nut, washer and yoke, then using tool J-25104, install pinion oil seal.
24. Install yoke, washer and new pinion nut. Torque pinion nut to 210 ft-lbs.
Fig. 6 Measuring side gear-to-case clearance:
DIFFERENTIAL INSTALLATION & ADJUSTMENT
1. Install thrust washers on side gears, then install side gears in case.
2. Install thrust washers on pinion gears, then install pinion gears in case.
3. Install thrust block, then the pinion mate shaft lock pin in case. Position case on end.
4. Tap case lightly on flat surface to settle gears in position, then measure side gear-to-case clearance using two equal thickness feeler gauges inserted simultaneously between side gear and case. Clearance should be 0.000---0.006 inch. If clearance exceeds specifications, replace differential case.
5. Install ring gear on case, then start two bolts 180 degrees apart and tighten bolts evenly to seat gear. Install remaining bolts and torque to 55 ft-lbs.
6. Using driver handle J-7079-02 and installer J-22175, install differential bearings.
7. Install differential bearing cups onto bearings, then install differential in axle housing. Install bearing caps and bolts and tighten securely, but not to specifications.
8. While holding ring gear in contact with pinion gear, pry differential bearing caps towards center of case, then insert feeler gauges of various thicknesses between each bearing cup and axle housing until proper ring gear backlash of 0.001---0.002 is established. Feeler gauges must be installed at both ends of differential at same time to obtain an accurate measurement.
9. Assemble shim pack to provide ring gear backlash as established in step 8, then insert shim packs between bearing cups and housing. Check ring gear backlash with feeler gauges. If satisfactory, remove, tag and set shims aside. If not satisfactory, adjust shims as necessary to bring backlash within specifications.
10. Remove differential case, then add an additional 0.015 inch shim to shim pack to be installed on drive tooth side of ring gear.
11. Remove differential bearings, then install shim packs on appropriate sides of differential case and install bearings.
Fig. 1 Spreader tool installation:
12. Install spreader tool, J-24385-01, adapters, J-24161 and dial indicator set, J-8001. Zero indicator and ensure indicator stylus contacts one side of housing opening.
13. While observing micrometer, spread housing with tool. Do not spread housing more than 0.020 inch or distortion could result.
14. Lubricate axle bearing with gear lube, then install bearing cups on bearings.
15. Install differential assembly in housing. Use suitable rawhide mallet to seat bearings. Ensure ring and pinion gear teeth mesh properly.
16. Remove spreader tool, then install bearing caps. Ensure reference marks made during disassembly are aligned. Apply sealing compound to bearing cap bolts and install. Torque bolts to 40 ft-lbs.
17. Measure ring gear backlash at two points with dial indicator. Backlash should be 0.005---0.010. If backlash is not within specifications, add or subtract shims from differential bearing shim packs as necessary until correct backlash is obtained. Changing position of a 0.005 inch shim from one side to the other will change amount of backlash 0.003 inch.
18. Measure ring gear run-out. If run-out exceeds 0.006 inch, case may be distorted or dirt may be trapped between ring gear to case flange. Check and correct as necessary.
19. Install front axle assembly. Refer to "Front End & Steering Section" for procedure.
20. Install gear housing cover using new gasket or RTV sealer. Torque bolts to 20 ft-lbs.
21. Fill axle with 2.5 pints of SAE 75---90 gear lubricant.
22. Road test vehicle.