Fixing Chevrolet C10 Rearend - Bulletproof 12-Bolt

The pinion seal is then pressed into the housing…

…followed by the yoke. The pinion nut is torque to spec (20-25 in/lb), compressing the crush sleeve, thereby setting the bearing preload.

The backlash can now be checked using a fixed position dial indicator. Three separate positions on the gear are checked with a minimum of 0.011-inch “slop” deemed acceptable.

Next, the gear tooth contact pattern is checked. Gear marking compound is applied to both the ring and pinion gear and the resulting pattern is compared to the manufacturer’s specs. To correct the pattern, a general rule of thumb is that if the pattern is heavy at the toe (top), subtract shims. If it’s heavy at the heel (bottom), add shims. At this point, it may be necessary to remove or add shims or reset the pinion to achieve the proper backlash and gear contact pattern.

Currie’s guys are well versed so it was only necessary to make one small adjustment before we were installing the Ford backing plates and new axles.

The axle retaining plate hardware is torqued to 45 lb-ft, accessible via holes on the axle flange.

The rearend cover attaches via twelve fasteners (hence the name). Before fastening the cover, each hole is given a quick cleanup via a hand tap.

Each fastener is then tightened to 25 lb-ft.

And there you have it! A 12-bolt rearend that will give any 9-inch Ford a run for its money!