Drive Pinion Rear
DRIVE PINION REAR REMOVAL / INSTALLATIONRemoval Note
1. Remove the differential case.
2. Install a Nm (inch-pound) torque wrench on the pinion nut and record the torque required to maintain rotation of the pinion through several revolutions.
3. Remove the rear pinion seal.
4. Install ST 205-460 or equivalent and, with a soft-faced hammer, drive the pinion assembly out of the front bearing cone and remove the drive pinion through the rear of the housing.
5. Remove the rear axle drive pinion shaft oil slinger.
6. Remove the outer pinion bearing.
7. Remove the drive pinion collapsible spacer and discard it.
8. Use Bearing Pulling Attachment ST 205-D064 or equivalent to remove the inner pinion bearing.
Note:
^ Do not remove the pinion bearing cups from the carrier casting unless the cups are damaged.
9. Remove the outer differential bearing cup with a hammer and brass drift.
10. Remove the inner differential bearing cup with a hammer and brass drift.
Installation Note
1. Position Pinion Bearing Cup Replacer ST 49 UN01035 and the inner and outer bearing cups in their respective bores.
(1) After placing the inner and outer bearing cups in their bores, place ST 49 UN01 035 (inner) on the inner pinion bearing cup.
(2) Place ST 49 UN01 035 (outer) on the outer pinion bearing cup.
(3) Install ST 49 UN01 035.
2. Tighten ST 49 UN01 035 to seat the pinion bearing cups into their bores.
Note:
^ Steps 3 and 4 are an alternate method of performing Steps 1 and 2.
3. Drive the outer pinion bearing cup into the axle housing using Driver Handle ST 49 F027 003 and Pinion Bearing Cup Replacer ST 49 UN01 035.
4. Drive the inner pinion bearing cup into the axle housing using Driver Handle ST 49 F027 003 and Pinion Bearing Cup Replacer ST 49 UN01 035.
Caution:
^ Whenever the cups are replaced, the pinion bearings must also be replaced.
Note:
^ If a feeler gauge can be inserted between a cup and the bottom of its bore at any point around the cup, the cup is not properly seated.
5. Make sure the cups are properly seated in their bores.
6. Install the original oil slinger and rear bearing onto Middle Pinion ST 49 8531 565.
7. Install Collar B ST 49 UN27 004 and O-ring to Middle Pinion ST 49 8531 565 and install them into the rear axle casing.
8. Install Collar A ST 49 UN27 003, yoke and washer.
9. Tighten the nut on Middle Pinion ST 49 8531 565 making sure the yoke can be turned by hand.
10. Tighten the nut on Middle Pinion ST 49 8531 565 making sure the yoke can be turned by hand.
11. If 7.5 inch differential, install Gauge Block (Front) 205-129 onto Middle Pinion ST 49 8531 565.
12. If 8.8 inch differential. install Gauge Block (Front) ST 49 UN27 001 and Gauge Block (Rear) ST 49 UN27 002 onto Middle Pinion ST 49 8531 565.
13. Place ST assembly on a surface plate and set the dial indicator to zero.
14. Place Gauge Set ST 49 0727 570 on top of Gauge Block (Front) ST 49 UN27 001.
15. Place the pointer of the dial indicator so that it contacts where the side bearing is installed in the housing. Measure the lowest position on the left and right sides of the casing.
16. Add the right and left side measurements and divide by two to get the thickness dimension.
Specification: 0 mm {0 inch}
17. If not within specification, adjust the pinion height by selecting a shim which will bring the reading within specification.
Note:
^ If the drive pinion is marked with a plus (+) reading, this amount must be added to the thickness dimension.
If the drive pinion is marked with a minus (-) reading, this amount must be added to the thickness dimension.
The rear bearing must be the exact same as the one used in the previous steps.
18. Measure the oil slinger/selective shim with a micrometer to verify the oil slinger/selective shim thickness.
19. Use a press and Pinion Bearing Cone Replacer ST 49 UN01 036 to press the pinion bearing until it is firmly seated on the pinion and pinion shim.
20. Place a new drive pinion collapsible spacer on the pinion shaft against the pinion stem shoulder.
21. From inside the rear axle housing, install the drive pinion assembly (drive pinion, shims, inner pinion bearing, and drive pinion collapsible spacer) into the rear axle housing bore.
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.
22. Install a new rear axle drive pinion seal.
(1) Install the outer pinion bearing.
(2) Install the rear axle drive pinion shaft oil slinger in the rear axle housing.
(3) Install the rear axle drive pinion seal on Pinion Seal Replacer ST 49 UN01 031.
Note:
^ Coat the lips of the seal with appropriate grease.
23. Place Pinion Seal Replacer ST 49 M005 796 in the rear axle drive pinion seal bore, and drive the rear axle drive pinion seal into place.
24. Lubricate the rear companion flange splines with lubricant.
Note:
^ Disregard the scribe marks if a new rear companion flange is being installed.
25. Align the rear companion flange with the drive pinion shaft.
26. Install the rear companion flange using ST 205-002 or equivalent.
27. Position the new pinion nut.
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.
28. Use Coupling Holder ST 205-126 to hold the companion flange while tightening the pinion nut.
Note:
^ If the original recorded preload is lower than specifications, tighten to the appropriate specifications for used bearings. If the preload is higher than specification, tighten the nut to the original reading as recorded.
Pinion bearing preload (new pinion bearings)
Tightening torque 1.8 - 3.3 Nm {18.4 - 34 kgf-cm, 16 - 29 inch lbs.}
Pinion bearing preload (used pinion bearings)
Tightening torque 0.9 - 1.5 Nm {9.1 - 15.3 kgf-cm, 8 - 14 inch lbs.}
^ If additional adjustment are necessary, see SPECIFICATIONS.
29. Install the differential case in the rear axle housing.