GM 14 Bolt 10.5 Differential Master Overhaul Kit ZK GM14T-C

The USA Standard ZK GM14T-C is a complete master overhaul kit for the GM 10.5-inch 14-bolt full-floating rear differential, the heavy rear axle under 3/4- and 1-ton Chevrolet and GMC trucks, Suburbans, and full-size vans. It carries everything you replace when the diff comes apart: new carrier bearings and races, pinion bearings and races, a pinion seal, a full shim kit, ring gear bolts, a pinion nut, crush sleeve where the design uses one, and the case gasket, plus threadlocker and a setup brush.

You reach for this kit any time the differential is open, whether you are installing new gears, swapping in a carrier or limited-slip, or chasing a howl or whine that turns out to be worn bearings. A 14-bolt that groans on deceleration, whines under load, or shows play at the pinion flange is telling you the bearings are done. Reusing old bearings after you have disturbed pinion depth or backlash is how a rebuild comes back noisy, so the bearings, races and seal all get replaced as a set.

This kit uses Koyo bearings and races and includes the complete shim pack so you can set pinion depth and carrier preload to spec during assembly. It is an overhaul and install kit, not a ring-and-pinion set, so the gears are not included; pair it with your gear set or reuse existing gears if they are in good shape. GM built the 10.5-inch 14-bolt across several production designs, so confirm your axle matches the -C coverage by year and pinion-bearing design before ordering. Ships from the USA; handling in 1-2 business days.