Complete Koyo bearing, race, seal and shim overhaul kit for rebuilding or re-gearing the GM 10.5-inch 14-bolt full-floating rear differential.
The GM 10.5 in. 14-bolt full-floater is the rear axle under 3/4- and 1-ton Chevrolet and GMC trucks, Suburbans and Express and Savana vans, and it is famous for living through anything except neglect. When one starts to howl on the highway or leak at the pinion after years of towing, the bearings are usually what is worn out. The USA Standard Gear ZK GM14T-C is the master overhaul kit for the 1998-and-newer version of that axle, with new Koyo bearings and races plus the seal, shims and small parts to set the gears up again. USA Standard Gear is a Yukon Gear & Axle line, and this kit is new.
Because the 14-bolt is a full-floating axle, the truck's weight rides on hub bearings on the axle tubes, and the center section only carries torque. That torque is still huge. The 14-bolt pinion is supported by three bearings: the two tapered bearings on the pinion shaft and a small pilot bearing at the nose of the pinion, inside the carrier housing. The carrier rides on two side bearings. Wear in any of them lets the pinion walk away from the ring gear under load, and the contact pattern moves to the edge of the teeth. The kit contents published for the ZK GM14T-C are carrier bearings and races, pinion bearings and races, the pilot bearing, a pinion seal, a complete shim kit, a pinion nut, a crush sleeve, thread locker, marking compound with a brush, and the cover gasket.
Rule out the wheel ends first: with the rear raised, rock each tire top to bottom and spin it by hand. Hub bearing wear on a full-floater makes a grinding noise that changes in turns, while center-section noise follows load. Drain and inspect the oil, then pull the cover and check backlash with a dial indicator against the factory pattern. If the hubs are the problem instead, the 14-bolt wheel bearing and seal kit is the part you need.
The ZK GM14T-C is listed for 1998-and-up GM 10.5 in. 14-bolt truck axles. GM made running changes to the 14-bolt over the years, and earlier axles take different bearings: the ZK GM14T-A kit covers 1988-and-older axles. Two look-alikes catch buyers out. GM also built a 9.5 in. semi-float 14-bolt for lighter trucks, and most 2001-and-later 2500HD and 3500 pickups use the American Axle 11.5, which also has a 14-bolt cover and takes the AAM 11.5 overhaul kit instead. Measure the ring gear or read the axle code, or send us the year and VIN and we will confirm. A Timken version, the Yukon YK GM14T-C, fits the same axle. Note that ring gear bolts are not in the published contents for this kit, so plan to reuse good bolts or buy new ones.
| Type | Differential master overhaul and bearing install kit |
| Fitment | GM 10.5-inch 14-bolt full-floating rear axle, Chevrolet/GMC 2500 and 3500 |
| Bearings | Koyo carrier and pinion bearings and races |
| Includes | Carrier and pinion bearings and races, pinion seal, complete shim kit, ring gear bolts, pinion nut, crush sleeve, case gasket, threadlocker |
| Manufacturer part number | ZK GM14T-C |
| Use | Rebuilding, re-gearing or resealing the 14-bolt differential |
| Not included | Ring and pinion gears; kit is bearings, seals and hardware only |
| Brand | USA Standard Gear |
Yes. The pilot bearing is in the published contents along with the carrier and pinion bearings and races, pinion seal, shims, pinion nut, crush sleeve, thread locker, marking compound and gasket.
They are not in the manufacturer's published contents for this kit. Reuse undamaged bolts with thread locker, or order new ones.
Most 2001-and-later GM 2500HD and 3500 pickups use the American Axle 11.5, which needs a different kit. Vans and some other models kept the 10.5 14-bolt. Check the ring gear size or axle code, or send us your VIN.
Koyo carrier and pinion bearings and races. The Yukon YK GM14T-C is the Timken-bearing version for the same axle.
Not unless you are changing ratio or the teeth are damaged. Good original gears can be set back to their old pattern using this kit.
