Bearing, race, seal and shim overhaul kit for rebuilding or re-gearing the early GM 10.5-inch 14-bolt full-float truck axle, 1988 and older.
If your 1988-or-older Chevy or GMC 3/4-ton or 1-ton pickup, Suburban or van has started to howl at highway speed, clunks when you go on and off the throttle, or keeps dripping gear oil off the pinion yoke, the 10.5 inch 14-bolt full-float center section is telling you its bearings are done. This GM14T-A master overhaul kit (part number ZK GM14T-A) is the A-series kit built for those early axles. It puts every bearing, race, seal and shim the center section uses in one box, so the axle goes back together with new parts instead of a mix of new bearings and tired hardware.
The 10.5 inch 14-bolt is a straddle-mounted design: the pinion rides on two tapered roller bearings in the nose of the housing plus a pilot bearing pressed into the case behind the pinion head. That third bearing is why the 14-bolt pinion almost never deflects under load, and it is why this kit carries a pilot bearing that most car-axle kits do not have. The two carrier bearings hold the ring gear, and shims behind them set backlash and carrier preload. Shims under the inner pinion race set pinion depth.
The kit contains carrier bearings and races, inner and outer pinion bearings and races, the pilot bearing, pinion seal, a complete shim kit, pinion nut, crush sleeve, cover gasket, thread locker, and gear marking compound with a brush. Ring gear bolts are not part of the A kit, so reuse good originals or buy new ones before you start.
Separate gear noise from bearing noise first. A note that changes between drive and coast usually means gear contact or pinion bearings; a steady growl that rises with road speed regardless of throttle is more often a hub bearing on this full-float axle. Our whine on acceleration vs deceleration guide and pinion bearing noise guide walk through it. Pull the cover, check the magnet, and paint a few ring gear teeth. If the gear teeth are pitted, bearings alone will not quiet it; plan on a ring and pinion such as this 4.11 14-bolt gear set. The wider picture of what fails in this axle is in our GM 14-bolt problems and rebuild cost guide.
This kit fits the GM 10.5 inch 14-bolt full-floating rear axle built in 1988 and earlier, found under Chevrolet and GMC 3/4-ton and 1-ton trucks, Suburbans and vans. GM changed pinion bearings in 1989 and again around 1998, so the 14-bolt kits are split by year: A for 1988 and older, B for 1989 to 1997, and C for 1998 and up. Swapped axles are common on these trucks, so go by the axle, not the truck. Check the date code stamped on the axle tube or measure the old pinion bearings, or send us the year and VIN and we will confirm. If your axle is 1998 or newer, use the GM14T-C master overhaul kit instead. This kit does not fit the 9.5 inch semi-float 14-bolt or the AAM 11.5 used from 2001. Other kits are under rebuild kits.
Work in the order Yukon publishes: pinion depth, pinion bearing preload, backlash, then carrier bearing preload. Yukon's setup chart for the 14T 10.5 lists 20 to 35 in-lb of pinion bearing preload with new bearings (8 to 11 in-lb on used), 0.006 to 0.011 inch backlash, 120 ft-lb on the ring gear bolts and 135 ft-lb on the carrier caps. Collapsing a crush sleeve on a pinion this size takes serious torque, so have a holding tool ready and creep up on preload; once you overshoot, the sleeve is scrap. Read the marking compound pattern on both sides of the teeth before the cover goes on, see our backlash and pinion depth setup guide. Fill with GL-5 gear oil, 75W-90 or 75W-140 for heavy towing, and add friction modifier only if the carrier is a clutch-type limited slip. While the axle shafts are out, check the hub bearings; the 14-bolt axle bearing and seal kit covers the wheel ends this kit does not.
| Manufacturer part number | ZK GM14T-A |
| Fitment | GM 10.5-inch 14-bolt full-floating rear axle, 1988 and older |
| Includes | Carrier bearings and races, pinion bearings and races, pilot bearing, pinion seal, shim kit, pinion nut, crush sleeve, gasket, thread locker, marking compound and brush |
| Not included | Ring and pinion gears |
| Brand | USA Standard Gear |
| Weight | 7.8 lb |
No. This is the A kit for axles built in 1988 and earlier. GM changed pinion bearings in 1989 and again around 1998, so a 1989 to 1997 axle needs the B-series kit and a 1998-up axle needs the GM14T-C kit. Check the axle date code, since many of these trucks have had axles swapped.
No. The A-series 14-bolt master kit leaves out ring gear bolts. Reuse undamaged originals with thread locker or buy a new set. Yukon's chart lists 120 ft-lb for the 14T ring gear bolts.
Neither. This kit covers the center section bearings, races, pilot bearing, pinion seal, shims, nut, crush sleeve and gasket. Gears are sold separately, and the full-float hub bearings and seals come in a separate 14-bolt axle bearing and seal kit.
You can use them as a starting point, which is how most installers begin, but the kit includes a complete shim set because new bearings rarely land at exactly the old dimensions. Set pinion depth first, then read the pattern before final assembly.
A GL-5 hypoid gear oil, typically 75W-90, with 75W-140 common on trucks that tow. Add friction modifier only for a clutch-type limited slip. Change the oil after break-in because new gears and bearings shed fine metal early.
