Reider Racing supplied not only the Precision Gear 3.73 ring-and-pinion for the 8.8, but also a Master Overhaul Kit consisting of all new bearings, seals, a new pinion nut, shims, and setup paint. Reider also now offers setup bearings that slide over the pinion so you don't have press to the bearing on and off if you miss the initial pinion depth setting. | 
This is the Zexel Torsen differential. It's difficult to see the internal worm gears, but they automatically operate to create a torque bias in the direction of the tire with the most traction. The other selling point is this unit's durability. |
This tight view of the stock differential shows how the side and pinion gears just chewed themselves to death. | 
Blankenship reused the stock pinion shim to set up the new gears. Generally, this works pretty well. Because he thought it would work, he didn't test the pinion depth using the setup bearings. |
The shim that establishes pinion depth fits between the pinion gear and the pressed-on pinion bearing (arrow). The setup bearings allow you to check this depth without hassling with pressing the bearing on and off. | 
The best way to press the pinion bearing on the shaft is with a large pipe and a hydraulic press. Don't hammer the bearing in place. |
New bearings also require new races. The best way to install the new races is to use a brass drift punch that won't damage the race. For the front pinion bearing, you can also use the old race to help drive in the new one. | 
With the new pinion bearing in place, don't forget the crush sleeve (arrow). This maintains a given amount of preload on the two pinion bearings to prevent the gear from moving in and out of the ring gear. |
Blankenship also installed new bearings on the new Torsen differential. He used a large socket to help drive on the new bearings. | 
To make sure everything fit before bolting it back into the housing, Blankenship test-fit the new axles, C-clips, and center pillow block to ensure there was room for everything. |
It required several attempts to create the proper backlash established by adjusting the right and left shim packs. | 
You can try to re-use the factory carrier shims, but these are cast pieces that generally break when you hammer them in place. The best solution is to use Reider Racing's adjustable side shim system (part of the Master install kit) that uses a modular shim case adjustable in thickness down to 0.001 inch and installs as one piece rather than a shim stack. |
Blankenship eventually achieved a backlash of 0.009 inch while the spec was between 0.008 and 0.010 inch--perfect. | 
Even when both the pinion depth and backlash are set up the way the book says, ultimately the gear pattern is all that matters. Here you can see the pinion is too deep into the ring gear. This means the pinion had to come out again for a 0.010-inch-thinner pinion shim that moved the pinion out toward the middle of the ring gear. |
After trying a new, thinner pinion shim, Blankenship got it right on the next try. | 
The last step was new axle bearings and seals, and sliding the axles in place and setting the C-clip. Then Blankenship added the cross-pin block, cross-pin, and the small bolt to secure the pin. He bolted on the rear cover, filled the rear with petroleum-based lube for the break-in period, and let Takahashi drive it home with a deeper gear and a much tighter limited slip. Takahashi reports that life is now good. CC |