Drive Pinion
Drive PinionPart 1 Of 3:
Part 2 Of 3:
Part 3 Of 3:
Special Tool(s)
1. Remove the axle assembly.
2. Remove the differential housing cover and drain the lubricant from the rear axle.
^ Clean the gasket material from the differential housing cover and the differential housing.
3. NOTE: An inspection can find the cause of the concern and determine the resolution.
Carry out the following before disassembly.
^ Remove all the lubricant from the internal parts of the conventional differential assembly or Trac-Lok differential assembly. Visually inspect the parts for wear and damage.
^ Rotate the differential assembly to check for any roughness, indicating damaged bearings or gears.
^ Check the differential ring gear and pinion teeth for signs of scoring, abnormal wear, nicks or chips.
^ Use a magnet to search for hidden heavy metal particles indicating component damage.
4. CAUTION: The differential ring gear and pinion must be clean and dry to obtain an accurate reading.
NOTE: Measure the differential ring gear and pinion backlash at three equally spaced points around the ring gear.
Using the special fools, measure the differential ring gear and pinion backlash.
^ The backlash specification cannot vary more than 0.05 mm (0.002 inch) between points checked. A larger variation of backlash indicates gear or case runout concerns.
5. Remove the axle shafts.
6. CAUTION: Note the position of the mating letters stamped vertically and horizontally on the bearing caps and the differential housing before removing the bearing caps.
Remove the bolts and the bearing caps.
7. CAUTION: Do not spread the differential housing more than specified.
Using the special tools, spread the differential housing to specifications, linen remove the Dial Indicator Gauge with Holding Fixture.
8. CAUTION: It will be necessary to use large pry bars to remove the differential assembly from the differential housing. Do not damage the differential ring gear when carrying out this step.
CAUTION: Mark or tag the differential bearing cups, indicating from which side they were removed.
Remove the differential assembly with the bearing cups.
^ Remove the special tool after removing the differential assembly.
^ Inspect the differential bearing cups for deep scores, galling, and spelling.
9. CAUTION: Mark or tag the outboard spacers indicating from which side they were removed.
Remove the outboard spacers.
^ Inspect the spacers for nicks, bending, or grooved conditions.
10. CAUTION: Index-mark the pinion flange to the pinion shaft prior to removal.
Using a suitable tool to prevent the flange from turning, remove the pinion lock nut and washer.
11. Using the special tool, remove the pinion flange.
12. NOTE: There are drive pinion preload shims on the spline end of the pinion. These shims can stick to the pinion, the pinion bearing or they can fall out of the differential housing. Collect and keep the shims for reassembly.
Using a soft faced hammer and the special tool, tap the pinion out of the pinion bearing cup and remove it through the rear of the differential housing.
13. Using the special tools, remove and discard the pinion seal.
14. CAUTION: Do not nick the differential housing bore.
Using the special tools, remove the outer pinion bearing cup.
15. Using the special tools, remove the inner pinion bearing cup.
16. Using the special tools, remove the inner pinion bearing.
17. NOTE: Discard the drive pinion position shim if bent or nicked. If discarding the shim, measure and record the shim thickness.
Remove the oil slinger, if equipped, and the drive pinion position shim.
18. CAUTION: Do not disassemble the Trac-Lok differential assembly or the Truetrac differential assembly. Discard the entire assembly if worn or damaged.
Carry out the following after disassembling the axle:
^ Thoroughly clean all parts.
^ Inspect all parts for damage and wear.
^ Clean the inside of the differential case before assembly. For Truetrac differentials, submerge the entire differential assembly in a suitable solvent to wash away contaminates from within the housing.
19. NOTE: Differential bearings shims are available in thicknesses of 0.762, 0.787, 0.813, 0.838, 0.864, 0.889, and 0.914mm (0.030, 0.031, 0.032, 0.033, 0.034, 0.035, and 0.036 inch).
NOTE: If damaged, install new differential bearing shims.
NOTE: Install new differential bearings and cups if removing the bearings from the differential case.
Using the special tools, remove the differential bearings.
^ Tag the selective outboard spacers to identify the side from which they were removed. If the differential bearings are removed, add the bearing shims to the spacers for the appropriate side.
20. NOTE: Use a vise with brass jaws or wood blocks.
Place the differential case in a vise.
21. CAUTION: Do not damage the anti-lock speed sensor ring when removing the differential ring gear. If removing the anti-lock speed sensor ring, discard it and install a new one.
NOTE: Always use new bolts upon reassembly.
Remove the ring gear bolts. Leave four bolts loosely assembled, 90 degrees apart.
22. Tap each bolt head alternately with a rawhide or plastic hammer to loosen the differential ring gear. Remove and discard the bolts. Remove the differential ring gear.
23. If necessary, remove the anti-lock speed sensor ring with a soft-faced hammer. Discard the anti-lock sensor ring.
24. Using a small drift, drive out the differential pinion shaft lock pin.
25. Using a drift, remove the differential pinion shaft.
26. To remove the differential side gears and the differential pinion gears, rotate the differential side gears. The differential pinion gears will turn to the opening in the differential case.
27. Remove the differential pinion gears and the differential pinion thrust washers behind the differential pinion gears.
28. Lift out the differential side gears and the differential side gear thrust washers.
Assembly
1. NOTE: For Truetrac and Trac-Lok differential assemblies, proceed to Step 7.
NOTE: Use a vice with brass jaws or wood blocks.
Place the differential he a vise.
2. Lubricate and assembly troth differential side gears and differential side gear thrust washers. Lubricate and assemble the differential pinion gears and the differential pinion gear thrust washers.
3. Install the differential side gears and washers in the differential case. Hold the side gears in place while installing the differential pinion gears in the differential case.
4. NOTE: Use a drift to align the pinion gear holes with the pinion shaft holes.
Rotate the differential side gears to align the differential pinion gears with the holes in the differential case for the differential pinion shaft.
5. Assemble the differential pinion shaft. Use a soft faced hammer to tap on the differential pinion shaft to remove the drift.
6. Align the lock pin hole in the differential case with the differential pinion shaft lock pin hole. Insert the lock pin and peen the metal of the differential case over the differential pinion shaft lock pin in two places, 180 degrees apart to lock it in place.
7. NOTE: Align the tab on the anti-lock speed sensor ring with the slot in the differential case.
NOTE: Apply Threadlock and Sealer to the new bolts.
Start two bolts through the differential case flange, the anti-lock sensor ring, and into the differential ring gear to make sure the differential ring gear and differential case align.
8. Press the anti-lock speed sensor on the differential case. The differential case flange acts as a pilot for the anti-lock speed sensor ring.
9. NOTE: Apply Threadlock and Sealer to the new bolt threads.
Draw up the new ring gear bolts alternately and evenly to specifications.
10. Install the outboard spacers in the side from which they were removed.
11. NOTE: Remove all nicks, burrs, dirt, etc. from the differential case hubs, to allow the special tools to rotate freely.
Place the special tools of the differential case hubs and position the assembly into the differential housing.
12. NOTE: The rear axle uses a combination of differential bearing shims and selective outboard spacers to control differential case end play. The old outboard spacers provide a good starting point when setting end play. However, if additional shimming is necessary, beyond what the hardened differential bearing shims can provide, select and install different thickness outboard spacers.
Mount the special tools as shown. Locate the tip of the Clutch Housing Gauge on a flat surface of one of the bolts.
13. NOTE: Repeat this and the following step until the same readings appear on the indicator each time. This is the total differential bearing shim thickness necessary, less preload. The final calculation occurs later during assembly.
Force the differential case as far as possible toward the indicator. With force applied, set the indicator at 0.
14. Force the differential case as far as it will go in the opposite direction. Record the total differential case end play reading.
15. After making sure the reading is repeatable, remove the special tools and the differential from the differential housing. Do not remove the Master Bearings from the differential case at this time.
16. Position the special tools and the inner and outer pinion bearing cups in their respective housing bores.
1 After placing the inner outer bearing cups in their bores, place the special tool (inner) on the inner pinion bearing cup.
2 Place the special tool (outer) on the outer pinion bearing cup.
3 Install the special tool.
17. Tighten the special tool to seat the pinion bearing cups into their bores.
18. CAUTION: Always install new pinion bearings when installing new bearing cups.
NOTE: If the feeler gauge can fit between a cup and the bottom of its bore at any point around the cup, remove and reseat the cup.
Check that the cups have seated correctly in their bores.
19. CAUTION: If any of the gauge surfaces have nicks in them, remove the high spots with a medium India oilstone to prevent erroneous readings.
NOTE: Apply a light oil film on the pinion bearings before assembling the tools.
Assemble and position the following in the differential housing.
1 Position the special tool.
2 Position the special tool.
3 Position the inner pinion bearing.
4 Position the special tool.
5 Position the special tool.
6 Position the outer pinion bearing.
7 Thread on the special tool.
20. NOTE: This step simulates pinion bearing preload.
Using a Nm (inch-pound) torque wrench, tighten the Handle to specification.
21. NOTE: Offset the Gauge Block to obtain an accurate reading.
Rotate the Gauge Block several half turns to make sure the pinion bearings are correctly seated and position the Gauge Block.
22. Install the special tool.
1 Position the special tool.
2 Install the bearing caps.
3 Install the four bolts.
23. NOTE: The service tools designed for a nominal pinion with 0 etch.
NOTE: Use a feeler gauge or clean, flat drive position shims as a measuring device.
NOTE: Do not attempt to force the feeler gauge or shims between the Gauge Block and the Gauge Tube. A slight drag indicates a correct selection.
Measure between the Gauge Block and the Gauge Tube. Record the measurement.
24. CAUTION: Follow the drive pinion bearing preload shim and drive pinion position shim assembly as directed or unit failure can result.
Install the correct thickness drive pinion position shim, and the oil slinger, if so equipped, on the pinion.
25. NOTE: Always use the same new inner pinion bearing installed when taking the measurement for drive pinion position shim selection.
Using the special tools and a suitable press, install the inner pinion bearing.
26. NOTE: Use the thickness of the old drive pinion bearing preload shims as a starting point for setting pinion bearing preload.
Inspect the drive pinion bearing preload shims for damage. Discard them if necessary. New shims are available in the thickness shown in the following chart.
Available Drive Pinion Bearing Preload Shims
27. Assemble the drive pinion preload shims onto the pinion and install the pinion into the differential housing.
28. NOTE: Do not install the pinion oil seal at this time.
Using the special tool, install the pinion flange.
29. Install the old washer and pinion locknut.
30. Using a Nm (inch-pound) torque wrench, rotate the pinion. The torque must read as specified.
^ To increase the bearing preload, remove drive pinion bearing preload shims. To decrease the preload, add pinion bearing preload shims.
31. With the drive pinion bearings at the correct preload as determined in this procedure, remove and discard the pinion locknut and washer.
32. Using the special tool, remove the pinion flange.
33. Coat the pinion seal rubber lips with the specified fill lubricant.
34. Using a suitable driver, install the differential pinion oil seal.
35. Coat the inner splines of the pinion flange with lubricant.
36. Using the special tool, install the pinion flange.
37. CAUTION: Always use a new washer add locknut.
Install the new washer and locknut. Torque to specification.
38. Install the outboard spacers in the side from which they were removed.
39. Place the differential assembly with the special tools in the differential housing.
40. Install the special tools. Locate the tip of the Clutch Housing Gauge on the flat surface of one of the bolts.
41. NOTE: Repeat this and the following step until the same readings appear on the indicator each time. This is the differential bearing shim thickness necessary between the differential case and the differential bearing on the differential ring gear side of the differential case.
Force the differential case and ring gear away from the drive pinion. With force applied, set the indicator to 0.
42. Force the differential ring gear into mesh with the pinion to obtain an indicator reading. Record this measurement.
43. Remove the differential case and the special tools from the differential housing.
44. Remove the Master Bearings from the differential case.
45. Place a shim of the thickness determined by the end play between the differential case and the ring gear/pinion on the ring gear side of the differential case. If additional shimming is necessary, beyond what the hardened differential bearing shim can provide, select and install a different thickness outboard spacer.
46. Using the special tool, install the differential bearing on the differential ring gear side of the differential case.
47. Determine the correct shim thickness and place the shim on the differential case hub on the drive pinion side.
^ To determine the correct shim thickness, first subtract the thickness of the ring gear side differential case hub shim from the total differential case end play reading recorded earlier. Then, add 0.25mm (0.010 inch) to this amount. This result is the correct thickness of shim to place on the pinion side differential hub. If additional shimming is necessary, beyond what the hardened differential bearing shim can provide, select and install a different thickness outboard spacer.
48. Using the special tools, install the differential bearing.
1 Place the special tool on the differential bearing to protect it during the installation of the opposite bearing.
2 Using the special tool, drive the differential bearing onto the hub.
49. Assemble the differential bearing cups to the differential bearings.
50. CAUTION: Do not spread the differential housing more than specified.
CAUTION: Avoid nicking the ring gear teeth and the anti-lock speed sensor ring during assembly.
Using the special tools, spread the differential housing to specifications.
1 Use a rawhide hammer to seat the differential in the differential housing.
2 Remove the special tools.
51. CAUTION: Match the mating letters as noted during disassembly.
Install the bearing caps, aligning the letters with those on the differential housing. Tighten the bolts to specifications.
52. Confirm the total preload.
^ Using a Nm (inch-pound) torque wrench, check the torque to rotate the pinion. The reading must be higher than the initial reading taken without the differential case installed by the amount shown.
53. Carry out the Tooth Contact Pattern Check to verify the final pinion position is correct.
54. Install the axle shafts.
55. CAUTION: Clean both flat surfaces (differential housing and differential cover) with a suitable solvent to remove all traces of oil film.
CAUTION: Install the differential cover within 15 minutes of applying the silicone or it will be necessary to remove and reapply new sealant.
Apply a continuous bead of sealant of the specified thickness to the differential housing cover.
56. Place two bolts into the differential housing cover at the 8 o'clock and 2 o'clock positions. Install the differential housing cover on the differential housing.
57. Install the remaining bolts. Tighten the bolts alternately and evenly.
^ Allow a one hour cure time before filling the axle with the correct amount of specified lubricant.
58. Install the axle assembly.