All those powerslides and autocrossing escapades finally took their toll on Mark Takahashi's '97 Mustang Cobra. Mark likes to drive exuberantly, and it didn't help the bone-stock 8.8-inch rear when he bolted on the entire Hotchkis chassis catalog for his SN-95 Mustang. While the Ford 8.8-inch rear axle assembly is plenty durable, Mark managed to chew enough of the spider and side gears that the chips ended up in between the ring and pinion and caused even more carnage. Ultimately, it was time for not only a new set of gears but a new limited slip as well. He called the guys at Reider Racing in Taylor, Michigan, with a request for a set of 3.73 gears. They recommended a set of cogs from Precision Gear, along with a Zexel Torsen T-2 gear-style limited-slip unit to replace the stock unit. The advantage to the Torsen is that it not only automatically biases torque to the wheel that can apply the most power, but it does so absolutely seamlessly and is constantly adjusting this torque bias depending upon traction at each rear wheel. Plus, the gear-style unit will last virtually the life of the vehicle, something that clutch- and cone-type limited slips have difficulty achieving. Mark took his ailing Mustang to our pal Dave Blankenship who owns Pro Tech in Van Nuys, California. Dave did the swap in an afternoon. Once the conversion was complete, the hardest part for Mark was keeping his foot out of it for about 500 miles while he carefully broke in the new gears and the Torsen limited slip. He has reported that the car is much more stable in the corners now because he can plant all the power coming off the corners. We're already laying bets on how long the clutch will last now that the rearend is new! CC Parts ListComponentPart Number3.73 gear setF88/373Master Install KitF88/MOKITSolid pinion shimF9SSKSTorsen T-2 limited slipF88/2T28Torsen T-2 road race styleF88/2THB Ford 8.8 SpecsPinion bearing preload, new brgs.16 to 29 in-lbPinion bearing preload, old brgs.8 to 14 in-lbRing gear bolt torque80 lb-ftMain cap bolt torque80 lb-ft 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.Reider Racing supplied not only the Precision Gear 3.73 ring-and-pinion for the 8.8, but a 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 is the Zexel Torsen differential. It's difficult to see the internal worm gears, but This tight view of the stock differential shows how the side and pinion gears just chewed themselves to death.This tight view of the stock differential shows how the side and pinion gears just chewed 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.Blankenship reused the stock pinion shim to set up the new gears. Generally, this works pr 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 shim that establishes pinion depth fits between the pinion gear and the pressed-on pin 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.The best way to press the pinion bearing on the shaft is with a large pipe and a hydraulic 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.New bearings also require new races. The best way to install the new races is to use a bra 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.With the new pinion bearing in place, don't forget the crush sleeve (arrow). This maintain Blankenship also installed new bearings on the new Torsen differential. He used a large socket to help drive on the new bearings.Blankenship also installed new bearings on the new Torsen differential. He used a large so 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.To make sure everything fit before bolting it back into the housing, Blankenship test-fit It required several attempts to create the proper backlash established by adjusting the right and left shim packs.It required several attempts to create the proper backlash established by adjusting the ri 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.You can try to re-use the factory carrier shims, but these are cast pieces that generally Blankenship eventually achieved a backlash of 0.009 inch while the spec was between 0.008 and 0.010 inch--perfect.Blankenship eventually achieved a backlash of 0.009 inch while the spec was between 0.008 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.Even when both the pinion depth and backlash are set up the way the book says, ultimately 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. CCThe last step was new axle bearings and seals, and sliding the axles in place and setting SOURCES Precision Gear Reider Racing Enterprises Taylor MI www.reiderracing.com Pro Tech Van Nuys CA Zexel Torsen Inc. Rochester NY www.torsen.com Enjoyed this Post? 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