Thrust Block Selection

Fig. 8 Side gear spread measurement. Eaton locking differential:

If cam gear, side gear, and/or shims have been replaced, or if it is necessary to replace thrust block and original dimension cannot be determined, use following procedure during differential case assembly to determine proper thrust block side.
1. Install fully assembled cam and side gears in case along with selected shims.
2. Install differential pinion shaft and secure with lock screw.
3. Wedge large screwdrivers or similar tools between pinion shaft and cam and side gears.
4. Measure distance between cam gear face and side gear face (side gear spread) using suitable gauge, Fig. 8, and record dimension. Ensure that gauge is ``square'' in case and that gauge bears against faces of gears, not gear teeth.
5. Select thrust block of a thickness zero to .006 inch less than dimension measured in step 4. Original thrust block can be reused if it is undamaged and will provide the specified zero to .006 inch clearance. Right side gear can also be reshimmed to obtain specified thrust block clearance, as long as specified .002-.010 inch backlash between side gear and differential pinions is maintained.