Pinion Gear: Service and Repair
Drive PinionPart 1 Of 3:
Part 2 Of 3:
Part 3 Of 3:
Special Tool(s)
Material
Removal
1. Remove the drive pinion flange.
2. Remove the axle shafts.
3. CAUTION: Mark the position of the differential bearing caps, as the arrows may not be visible. Always install the bearing caps in their identical locations and positions.
Remove the differential bearing caps.
1 Remove the bolts.
2 Remove the differential bearing caps.
4. WARNING: Do not allow the differential assembly to fall.
CAUTION: Place a block of wood between the pry bar and the differential housing to protect the machined surface from damage.
Using a pry bar and a block of wood, remove the differential assembly from the differential housing.
5. CAUTION: Separate and identify the bearing shims and bearing cups for location. Both the bearing shims and the bearing cups must be installed in the same position as removed.
Identify the removal locations of the bearing shims and bearing cups.
6. Remove the rear axle drive pinion shaft oil slinger.
7. Using the special tool and a soft-faced hammer, drive the pinion assembly out of the front differential pinion bearing and remove it through the rear of the differential housing.
8. Remove the differential drive pinion collapsible spacer and discard it.
9. Using the special tool and a suitable press, remove the differential pinion bearing.
10. NOTE: Do not remove the differential drive pinion bearing cups from the differential housing unless the cups are damaged.
Using a brass drift, remove the outer differential drive pinion bearing cups.
Installation
1. NOTE: This step and the following step show the preferred method for installing the differential drive pinion bearing cups. An alternate method is shown following these two steps.
Position the special tools and the inner and outer differential drive pinion bearing cups in their respective bores.
1 After placing the inner and outer bearing cups in their bores, place the special tool on the inner bearing cup.
2 Place the special tool on the outer bearing cup.
3 Install the special tool into the replacer tools.
2. Tighten the special tool to seat the differential drive pinion bearing cups into their bores.
3. NOTE: This step and the following step are alternate methods for installing the differential drive pinion bearing cups. Carry out these two steps if differential drive pinion bearing cup installation was not done in the previous steps.
Using the special tools, drive the outer differential drive pinion bearing cup into the differential housing.
4. Using the special tools, drive the inner differential drive pinion bearing cup into the differential housing.
5. CAUTION: Always install new differential pinion bearings when installing new differential drive pinion 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.
6. NOTE: Apply only a light lubricant film on the differential pinion bearings before assembling the tool.
Assemble and position the following in the differential housing.
7. NOTE: This step duplicates final differential pinion bearing preload.
Tighten the special tool to the specification shown.
8. CAUTION: Offset the special tool to obtain an accurate reading.
Rotate the special tool several half-turns to make sure the differential pinion bearings seat correctly and position the special tool as shown.
9. Install the special tool.
1 Position the special tool.
2 Install the differential bearing caps.
3 Install the bolts.
10. CAUTION: Use only flat, clean drive pinion bearing adjustment shims.
CAUTION: Selection of too thick a shim results in a deep tooth contact at final assembly. Do not attempt to force the shim between the Gauge Block and the Gauge Tube. A slight drag indicates correct shim selection.
Use a drive pinion bearing adjustment shim as a gauge for shim selection.
^ After determining the correct shim thickness, remove the special tools.
11. Position the correct thickness drive pinion bearing adjustment shim and the differential pinion bearing on the drive pinion. Using a suitable press and the special tools, press the differential pinion bearing until it seats firmly on the pinion.
12. Place a new differential drive pinion collapsible spacer on the pinion shaft against the pinion stem shoulder.
13. CAUTION: Installation without the correct tool can result in early seal failure.
Install a new rear axle drive pinion seal.
1 Install the front differential pinion bearing.
2 Install the rear axle drive pinion shaft oil slinger.
3 Position the rear axle drive pinion seal on the special tool.
14. CAUTION: If the rear axle drive pinion seal becomes misaligned during installation, remove the seal and install a new seal.
NOTE: Coat the rear axle drive pinion seal lips with grease.
Position the rear axle drive pinion seal in the seal bore, and use the special tool to drive the seal into place.
15. From inside the differential housing, install the drive pinion assembly (drive pinion, shims, bearing and the collapsible spacer) into the carrier bore.
16. Lubricate the pinion flange splines with rear axle lubricant.
17. NOTE: Disregard the index marks if installing a new pinion flange.
Position the pinion flange.
18. Using the special tool, install the pinion flange.
19. Position the new nut.
20. CAUTION: Do not, under any circumstance, loosen the nut to reduce preload. If it is necessary to reduce preload, install a new collapsible spacer and nut.
CAUTION: Remove the special tool while taking preload readings with the Nm (inch-pound) torque wrench.
Use the special tool to hold the pinion flange while tightening the nut.
^ Rotate the pinion occasionally to make sure the differential pinion bearings seat correctly. Take frequent differential pinion bearing preload readings by rotating the pinion with a Nm (inch-pound) torque wrench.
^ For new differential pinion bearings, tighten the nut to specification. Refer to torque specifications for new differential pinion bearings.
^ For used differential pinion bearings, if the preload recorded prior to disassembly is lower than the specification for used bearings, tighten the nut to specification. Refer to torque specifications for used differential pinion bearings.
^ For used differential pinion bearings, if the preload recorded prior to disassembly is higher than the specification for used bearings, tighten the nut to the original reading as recorded.
21. Place the differential assembly in the differential housing.
22. Install the bearing shims in the same location as when removed.
23. Install the bearing caps in their identified locations and tighten the bolts to specification.
24. Rotate the differential case to make sure it turns freely.
25. Using the special tools, measure differential ring gear backlash.
26. CAUTION: Align the index marks.
CAUTION: The driveshaft centering socket yoke fits tightly on the rear axle pinion flange pilot. To make sure that the yoke seats squarely on the flange, tighten the bolts evenly in a cross pattern as shown.
Install the driveshaft.