Corporate and Eaton

Fig. 13 Side bearing shim selection chart. Models w/7-1/2 inch ring gear:

Fig. 14 Measuring side bearing clearance w/feeler gauge:

MODELS W/7-1/2 INCH RING GEAR
On these models, side bearing preload should be set before pinion is installed. If pinion is installed, remove ring gear.
1. Ensure that bearing bores in housing and bearing caps are clean and free from burrs.
2. Measure production shims or service spacer and shim packs removed during disassembly to determine approximate thickness of shims needed for installation. Do not reuse cast iron production shims as they may break during installation. If service spacers and shims were previously installed, they can be reused.
3. In addition to .170 inch service spacers for each side, refer to chart, Fig. 13, and select service shim thickness required based on measurements made in step 2.
4. Place outer races over side bearings, mount differential assembly in housing and insert service spacer between each bearing race and housing with chamfered edge against housing.
5. Install left bearing cap to retain case assembly and tighten bolts hand tight so that case can be moved while checking adjustments. A bearing cap bolt can be installed in lower right bearing cap hole to prevent case from dropping while performing shim adjustments.
6. Select one or two shims totaling thickness calculated in step 3 and insert shims between right bearing cap and service spacer.
7. Insert progressively larger feeler gauges between shim and service spacer until noticeable increase in drag can be felt, pushing gauge down until it contacts housing bore to obtain proper reading, Fig. 14. Rotate case while inserting gauges to ensure even readings.
8. The gauge used just before additional drag is felt is correct thickness to obtain ``zero preload.'' By starting with a thin gauge a sense of feel can be obtained for the original light drag caused by the weight of the case, allowing the drag caused by the beginning of preload to be recognized. It will be necessary to work case in and out and to the left in order to insert feeler gauges. Insert feeler gauges as shown in Fig. 14, to ensure accurate measurement.
9. When the proper gauge thickness has been determined to obtain zero preload, remove bearing cap, case assembly service spacers and shim pack.
10. Select 2 service shims of approximate equal thickness whose total thickness is equal to the thickness of the shims installed in step 6 plus the thickness of the feeler gauge used to obtain zero preload.
11. Shims selected during this procedure allow differential assembly to be installed at zero preload, the equivalent of a ``slip-fit'' in case, during backlash adjustment. Final preload is not added until backlash has been adjusted.

Fig. 15 Side bearing preload adjustment. Models w/8-1/2 & 8-7/8 inch ring gear:

MODELS W/8-1/2 & 8-7/8 INCH RING GEAR
This procedure is performed after pinion assembly has been installed, and requires use of gauging tool J-22779 or equivalent. If gauging tool is not available, side bearing shim thicknesses can be determined by using procedure for 7-1/2 inch ring gears.
1. Ensure that bearing bores and caps are clean and free of burrs.
2. Lightly lubricate differential case bearings, install outer races on proper bearings, install differential in housing and support to prevent falling.
3. Install retaining strap J-22779-6 over left bearing cap, secure strap with cap bolts and evenly tighten bolts to obtain snug fit.
4. With ring gear tight against pinion (zero to .001 inch backlash), insert gauging tool J-22779 between left bearing race and housing, Fig. 15.
5. While oscillating tool, turn adjusting nut clockwise to force ring gear toward pinion until noticeable drag on tool can be felt, then tighten lock bolt on side of tool.
6. Insert a .170 inch service spacer between right bearing cap and housing, then select and install service shim that will easily slip between spacer and housing. Do not reuse cast iron production shims as they may crack during installation. If service spacers and shims were previously installed, they can be reused.
7. Insert progressively thicker feeler gauges between housing and service shim until slight drag can be felt when inserting gauge. Thickness of feeler gauge used to produce slight drag will be dimension C used in Fig. 15, to determine shim thickness.
8. Remove service spacer and shim, and gauge tool, without disturbing adjustment of tool.
9. Measure thickness of gauging tool at a minimum of 3 positions, average measurements and record average.
10. Add thicknesses of service spacer (A), shim (B) and feeler gauge (C), Fig. 15, and record sum.
11. Apply dimensions obtained in steps 9 and 10 calculation shown in Fig. 15, to determine proper left and right shim thicknesses.
12. Install shim selected for left side first, then wedge right shim between bearing race and service spacer. Position shims so that chamfer is toward outside. If chamfer in right shim is not sufficient to allow installation without damaging spacer, grind or file chamfer prior to installation. If difficulty is encountered installing right shim, partially remove case, insert shim, slide shim and case into position, then seat shim using soft-faced hammer while rotating differential case.
13. Install bearing caps and torque bolts to specifications, then check and adjust backlash as needed.