Differential Bearing Preload & Ring Gear Backlash
- With pinion depth set and pinion installed, place differential case and ring gear assembly with bearings and races into differential housing assembly.
- Install a .265" (6.73 mm) preload shim on left (ring gear side) side of differential case. Install left bearing cap, and tighten retaining bolts finger tight.CAUTION: Ensure bearing caps are installed in original location. Arrow or triangle area between bolt holes on bearing cap must point away from ring gear (toward axle shaft end of housing).
- Apply pressure on left (ring gear) side of differential case to ensure bearing is fully seated in bearing race. Select largest preload shim which will fit with on right (pinion) side. Preload shim should fit with a slight drag.
- Install preload shim on right (pinion) side of differential case. Install right bearing cap. Arrow or triangle area between bolt holes on bearing cap must point away from ring gear (toward axle shaft end of housing). Install and tighten all bearing cap bolts to specification. See TORQUE SPECIFICATIONS .
- Ensure differential case rotates smoothly. Using dial indicator, hold pinion and measure ring gear backlash. See Fig 1 . Ring gear backlash may be adjusted if not within .008-.015" (.20-.38 mm).
- If no ring gear backlash exists, remove .020" (.51 mm) from left (ring gear) side and add to right (pinion) side. If ring gear backlash is not within specification, note direction that differential case must be moved for backlash adjustment. See Fig 2 .
- Ring gear backlash can be changed by increasing thickness of one preload shim and decreasing thickness on the other preload shim the same amount. Changing preload shim thickness will change ring gear backlash a designated amount. See BACKLASH-TO-SHIM THICKNESS CONVERSION
.BACKLASH-TO-SHIM THICKNESS CONVERSION
Required Change In Backlash In. (mm) Change In Shim Thickness In. (mm) .001 (.03) .002 (.05) .002 (.05) .002 (.05) .003 (.08) .004 (.10) .004 (.10) .006 (.15) .005 (.13) .006 (.15) .006 (.15) .008 (.20) .007 (.18) .010 (.25) .008 (.20) .010 (.25) .009 (.23) .012 (.30) .010 (.25) .014 (.35) .011 (.28) .014 (.35) .012 (.30) .016 (.41) .013 (.33) .018 (.46) .014 (.35) .018 (.46) .015 (.38) .020 (.51) - Install proper preload shim. Tighten bearing cap bolts to specification. Rotate ring gear assembly several times. Recheck and correct ring gear backlash as necessary.
- Once correct ring gear backlash is obtained, remove bearing caps and preload shims. Increase both left and right preload shim thickness .006" (.15 mm), and reinstall to obtain correct bearing preload. Install bearing caps and tighten bolts to specification. See TORQUE SPECIFICATIONS .
- Using White marking compound, check gear tooth contact pattern. See GEAR TOOTH CONTACT PATTERNS article in GENERAL INFORMATION.