Differential Overhaul
Both standard and TRAC-LOK differential assemblies are used in rear mounted drive axles. Ring gear and side bearing service procedures are identical for both type assemblies. However, on the TRAC-LOK limited slip differential, only the ring gear and bearings can be serviced separately. The differential case and internal component should be serviced as an assembly and should not be disassembled.
Fig. 1 Differential exploded view. Model 44:
Fig. 2 Differential exploded view. Model 60:
STANDARD DIFFERENTIAL
Exc. Model 70
1. Support differential case and remove and discard ring gear bolts.
2. Remove ring gear from case, tapping with soft faced hammer.Do not pry gear from case as mounting surfaces will be damaged.
3. Drive out pin securing differential pinion shaft, then remove shaft.
4. Rotate side gear to roll differential pinions from case, and remove pinions and thrust washers, noting installation position for assembly.
5. Remove side gears and thrust washers from case, noting installation position.
6. Inspect components as outlined in cleaning and inspection, keeping all components in order, and replace as needed.
7. Remove side bearings from case using suitable puller, and note the following:
a. Ensure that puller bears against bearing inner race to prevent damage to rollers and cage.
b. Remove shims from behind each bearing and retain for assembly.
c. Keep bearings, races and shims for each side of case together to ensure proper assembly.
8. Coat all components with specified lubricant prior to assembly. Components that are to be reused should be installed in original position to ensure proper operation.
9. Install side gears along with thrust washers in respective sides of case.
10. Install thrust washers on differential pinions using grease to adhere washers.
11. Position pinion assemblies in case 180° apart, then roll pinions into alignment with pinion shaft bores, ensuring that thrust washers are in place.
12. Insert pinion shaft, aligning lock pin hole with hole in case, then secure shaft with new lock pin.
13. Support differential case, install ring gear and new ring gear bolts, then seat ring gear on case with suitable mallet.
14. Evenly torque ring gear bolts to 45---60 ft-lbs, for model 44 axle or 110---115 ft-lbs, for model 60 axle in crossing pattern.
15. Press specified master gauge bearings or selected side bearings onto case, then place races over respective side bearings, if used.
16. On model 44 axle, install spreader tool and dial indicator on axle housing and spread case 0.015 inch as outlined during disassembly, then remove dial indicator.Do not spread housing more than 0.020 inch as housing will be damaged. Leave spreader tool installed only long enough to perform necessary service to prevent permanent distortion.
17. On all models, mount differential in housing, install bearing caps, and tighten cap bolts hand tight and remove spreader if installed.
Fig. 6 Side bearing clearance check:
18. Mount suitable dial indicator on housing with plunger bearing against back of ring gear.
19. Pry differential case as far away from indicator as possible, inserting suitable lever between bearing race and housing.
20. Ensure that indicator plunger is still in contact with gear, then zero indicator.
21. Pry differential toward indicator, as far as possible, then record dial indicator reading.Repeat steps 19 - 21 until same reading is obtained each time. Recorded reading indicates shim thickness necessary to take up clearance between side bearings and housing. Shim pack thickness to be placed on bearing hubs between side bearings and case will be determined during "Final Assembly and Adjustment."
22. Remove dial indicator, bearing caps and differential assembly from housing, keeping side bearing races in proper position for assembly.
Fig. 7 Differential case exploded view. Model 70:
MODEL 70
1. Support differential case and remove and discard ring gear bolts.
2. Remove ring gear from case, tapping with soft faced hammer.Do not pry gear from case as mating surfaces will be damaged.
3. Scribe matching marks between differential case halves, remove studs and separate differential case.
4. Remove pinion spider, pinions and thrust washers, and side gears and thrust washers from case halves, noting installation position for assembly.
5. Inspect components as outlined in "Cleaning and Inspection," keeping all components in order, and replace as needed.
6. Remove side bearings from case using suitable puller and note the following:
a. Ensure that puller bears against bearing inner race to prevent damage to rollers and cage.
b. Remove shims from behind each bearing and retain for assembly.
c. Keep bearings, races and shims for each side of case together to ensure proper assembly.
7. Coat all components with specified lubricant prior to assembly. Components that are to be reused should be installed in original position to ensure proper operation.
8. Install side gears along with thrust washers in respective sides of case.
9. Mount differential pinions and thrust washers on spider, then install assembly in flanged side of case, ensuring that spider is fully seated.
10. Align matching marks and join case halves, holding side gear into case cover as it is positioned over flanged side and pinion assembly.
11. Install case mounting studs and evenly torque studs to 65 - 70 ft-lbs.
12. Position ring gear on case pilot, install new ring gear bolts hand tight, then seat ring gear on case using suitable mallet.
13. Evenly torque ring gear bolts to 100---110 ft-lbs, in crossing pattern.
14. Press specified master gauge bearings or selected side bearings onto differential case, then place races over respective side bearings, if used.
15. Mount differential in housing, install bearing caps and tighten cap bolts hand tight.
Fig. 6 Side bearing clearance check:
16. Mount suitable dial indicator on housing with plunger bearing against back of ring gear.
17. Pry differential as far away from indicator as possible, inserting suitable lever between bearing race and housing.
18. Ensure that indicator plunger is still in contact with gear, then zero indicator.
19. Pry differential toward indicator, as far as possible, then record dial indicator reading. Repeat steps 17 - 19 until same reading is obtained each time. Recorded reading indicates shim thickness necessary to take up clearance between side bearings and housing. Shim pack thickness to be placed on bearing hubs between side bearings and case will be determined during "Final Assembly and Adjustment."
20. Remove dial indicator, bearing caps and differential assembly from housing, keeping side bearing races in proper position for assembly.