GM 8.5 10-Bolt Differential Master Overhaul Kit ZK GM8.5

USA Standard Gear ZK GM8.5 is the master overhaul kit for the GM 8.5 inch 10-bolt rear differential, the axle under most rear-drive GM half-tons, G-bodies, Camaros, S-10s and full-size cars from the 1970s forward. It carries everything that wears out in a diff rebuild in one box, so you are not stopping mid-job to chase a pinion nut or a shim pack.

Inside: carrier bearings and races, pinion bearings and races, pinion seal, a complete shim kit, ring gear bolts, pinion nut, crush sleeve where the application uses one, plus oil baffles and slingers where the housing calls for them. Bearings and races are Koyo. Manufacturer part number ZK GM8.5.

On the bench the sequence is the same every time: press the old carrier bearings off, set pinion depth with the shim kit and a depth gauge, install a fresh crush sleeve and torque the pinion nut to spec while checking rotating torque, then shim the carrier for backlash and check your pattern with marking compound before the cover goes on. Because the shims are included as a full pack, you can adjust depth and backlash without ordering a second time.

This is the kit for a differential that is howling on decel, leaking at the pinion seal, or has been run low on gear oil and chewed the carrier bearings. It is a rebuild kit only - it does not include a ring and pinion set, a carrier, or gear oil.