Pinion Gear: Service and Repair

Drive Pinion











Special Tool(s)





Material
Removal
1. Remove the differential case.





2. Index-mark the driveshaft at the axle flange.





3. Remove and discard the bolts.





4. CAUTION: After removal of the pinion nut, discard it. A new nut must be used for installation.

Using the special tool, remove the pinion nut.





5. Index-mark the drive pinion flange and the pinion shaft.





6. Using the special tool, remove the pinion flange.





7. Force up on the metal flange of the rear axle drive pinion seal. Install gripping pliers to the seal flange and strike with a hammer until the rear axle drive pinion seal is removed.
Remove the oil slinger and the outer pinion bearing.





8. Install the special tool and, with a soft-faced hammer, drive the pinion out of the front bearing cone and remove it through the rear of the housing.





9. NOTE: Remove the collapsible spacer and discard it.

Use the special tool to remove the pinion bearing.





10. NOTE: Do not remove the pinion bearing cups from the carrier casting unless the cups are damaged.

NOTE: Tap alternately on opposite sides of the cups to prevent them from cocking in the bore.

Use a suitable brass drift to remove the differential bearing cups.

Installation
Using 205-098





1. Install the inner and outer bearing cups.
1 After placing the inner and outer bearing cups in their bores, place the special tool on the inner pinion bearing cup.
2 Place the special tool on the outer pinion bearing cup.
3 Install the special tool into the replacer tools.





2. Tighten the special tool to install the pinion bearing cups into their bores.

Using 205-DO55 and 205-153





3. Drive the outer pinion bearing cup into the axle housing, using the special tools.





4. Drive the inner pinion bearing cup into the axle housing, using the special tools.

Setting pinion depth





5. CAUTION: Whenever the cups are replaced, the differential pinion bearings must also be replaced.

Make sure the cups are properly seated in their bores.
If a feeler gauge of the specification shown in the illustration can be inserted between a cup and the bottom of its bore at any point around the cup, the cup is not properly seated.








6. NOTE: Apply only a light oil film on the pinion bearings before assembling the tool.

Assemble and position the special tools.





7. NOTE: This step duplicates final pinion bearing preload.

Tighten the Handle to achieve the specified rotational torque.





8. NOTE: The special tool must be offset to obtain an accurate reading.

Rotate the special tool several half-turns to ensure proper seating of the pinion bearings and position the special tool.





9. Install the special tool.
1 Position the special tool.
2 Install the differential side bearing caps.
3 Install the differential side bearing cap bolts.





10. NOTE: Drive pinion bearing adjustment shims must be flat and clean.

NOTE: A slight drag should be felt for correct shim selection. Do not attempt to force the pinion shim between the Gauge Block and the Gauge Tube. This will minimize selection of a pinion shim thicker than required, which results in a deep tooth contact in the final assembly of integral rear axle assemblies.

Use a drive pinion bearing adjustment shim as a gauge for shim selection.
After the correct shim thickness has been determined, remove the Gauge Tube.





11. CAUTION: Check the splines on the pinion stem to be sure they are free of burrs. If burrs are evident, remove them by using a fine crocus cloth, working in a rotational motion. Wipe the pinion clean.

NOTE: The same differential pinion bearing used in the following procedure must be used in the final assembly of the axle.

NOTE: Make sure the press load is not applied to the bearing cage.

Place the selected shim(s) on the pinion and press the bearing until it is firmly seated on the shaft using the special tools.





12. Place a new collapsible spacer on the pinion shaft against the pinion stem shoulder.








13. CAUTION: Installation without the correct tool can result in early seal failure. If the rear axle drive pinion seal becomes cocked during installation, remove it and install a new one.

NOTE: Coat the lips of the rear axle drive pinion seal with premium long-life grease.

Install a new rear axle drive pinion seal.
1 Install the outer pinion bearing roller.
2 Install the rear axle drive pinion shaft oil slinger in the rear axle housing.
3 Install the rear axle drive pinion seal on the special tool and install the seal.





14. Install the drive pinion in the drive pinion carrier bore from inside the rear axle housing. Seat the drive pinion with a plastic hammer.
15. Lubricate the pinion flange splines with clean synthetic rear axle lubricant.





16. NOTE: Disregard the scribe marks if a new pinion flange is being installed.

Align the pinion flange with the drive pinion shaft.





17. CAUTION: The special tool must be used due to tight spline fit.

With the drive pinion in place in the axle housing, install the pinion flange using the Companion Flange Replacer.





18. Position the new pinion nut.





19. CAUTION: Under no circumstances is the pinion nut to be backed off to reduce preload. If reduced preload is required, a new collapsible spacer and pinion nut must be installed.

Use the special tool to hold the pinion flange while tightening the pinion nut.
^ Refer to the torque specification for new pinion bearings.
^ Tighten the pinion nut until the desired rotational torque is reached.








20. NOTE: Align index marks.

Install new bolts and tighten as shown.
21. Install the differential case.