Differential Bearing Preload
- Apply thin coating of axle lubricant to bearing bores. Place bearing cups over side bearings and place differential case in housing. If ring and pinion gear set have timing marks, be sure to align timing marks during installation of differential case.
- Install a 0.200" gauge disc spacer on ring gear side (left side) of case between bearing cup and case. Install a 0.300" gauge disc spacer on pinion gear side (right side) of case between bearing and case. Install bearing caps in original positions and tighten bolts to 30 INCH lbs.
- Install adjuster rod (T78P-4136-AB) into ring gear side (left side) of axle tube and retain in position with existing brake backing plate bolts and nuts. Tighten adjuster rod nut to 40 INCH lbs. to move differential case to right side of housing. Rotate differential case several times to seat bearings and recheck adjuster rod nut torque (maintain 40 INCH lbs.).
- Using a feeler gauge, select thickest blade that will enter between gauge disc and carrier bore on ring gear side of case. Feeler gauge should fit with slight drag. Remove and record feeler gauge thickness. Add 0.500" to recorded feeler gauge thickness. See Fig 1.
- Release adjuster rod enough to remove 0.300" spacer disc. Remove right bearing cap and spacer disc. Install bearing preload spacer (T78P-4136-B2) between bearing cup and carrier bore. Reinstall bearing cap and tighten to 30 INCH lbs. Rock ring gear back and forth while tightening adjuster rod until zero backlash is obtained. Using a feeler gauge, repeat step 4. Add 0.200" to feeler gauge thickness.
- Left shim thickness is total recorded reading MINUS 0.008". Right shim thickness is total feeler gauge thickness recorded in step 4 and step 5 PLUS 0.200" subtracted from total recorded reading PLUS 0.016".NOTE: Side bearing shims are available in various thicknesses. If shim size required is not listed, round DOWN to nearest size available.
- Remove adjuster tool from axle housing. Remove bearing caps, disc spacer and preload spacer from carrier housing. Install carrier spreader and dial indicator. Spread carrier housing 0.016" (measured at top of housing). Remove dial indicator. Install left shim, push differential case and bearing cap to left and install right shim (tapping with plastic hammer if required). Release spreader and remove from housing.NOTE: Do not exceed differential case spread of 0.016".