Differential Case Bearing Preload And Gear Backlash

Fig 1: Adjuster Locks & Bolts

Courtesy of CHRYSLER GROUP, LLC

Backlash is adjusted by moving the adjusters in and out or both. By moving the adjusters the case/ring gear will move closer or further away from the pinion. In most cases this adjustment can be used to achieve the correct gear tooth pattern and set the case bearing preload.

1. Remove adjuster lock bolts (3) and adjuster locks (2).
2. Loosen  the differential bearing caps (4).
3. Slide differential case toward the pinion gear until the gears make contact/zero backlash. If zero backlash cannot be obtained, turn the pinion side adjuster until zero backlash is obtained.
   Fig 2: Turning Bearing Adjusters

   Courtesy of CHRYSLER GROUP, LLC
4. Holding the differential case (2) toward the pinion gear, turn bearing adjusters with Adjuster Wrench (special tool #8883A, Wrench, Differential Adjusting) (1) until adjuster makes contact with the differential bearings/cups.
5. Back off the ring gear side adjuster 4 holes, to obtain initial ring gear backlash.
6. Install ring gear side adjuster lock and bolt. Do not tighten  adjuster lock bolt at this time.
7. Tighten pinion gear side adjuster firmly against the differential case bearing cup.
8. Rotate the pinion several times to seat the deferential bearings.
9. Loosen pinion gear side adjuster until it is no longer in contact with the bearing cup, then tighten it until it makes contact.
10. Tighten pinion gear side adjuster an additional:
    • New Bearings:  6 Adjuster Holes
    • Original Bearings:  4 Adjuster Holes
11. Install pinion gear side adjuster lock and bolt.
12. Tighten bearing cap bolts to 281 N.m (207 ft. lbs.).
13. Tighten adjuster lock bolts to 25 N.m (18 ft. lbs.).
    Fig 3: Measuring Ring Gear Backlash

    Courtesy of CHRYSLER GROUP, LLC
14. Measure ring gear backlash with a Dial Indicator (special tool #C-3339A, Set, Dial Indicator) (1) and Pilot Stud (special tool #L-4438, Dial Indicator Post) at eight points around the drive side of the ring gear (2). The backlash should be 0.08-0.25 mm (0.003-0.010 in) with a preferred backlash of 0.13-0.18 mm (0.005-0.007 in).