Yukon Gear Master Overhaul Kit For GM 88 and Older 14T Diff
Square-body Chevy and GMC 3/4-ton and 1-ton trucks, Suburbans and vans from 1988 and earlier ride on the 10.5-inch 14-bolt full-float rear, and after decades of towing most of them are due. If yours howls on the highway, growls under a trailer, or has gear oil slung across the cover and pinion yoke, the Yukon YK GM14T-A puts every bearing and seal for the center section in one box, with Timken bearings and races.
Yukon's technical note says this kit does not come with ring gear bolts, so check yours before teardown and have new ones on hand if the threads or heads are damaged.
Because the 14-bolt is a full floater, the axle tubes and hub bearings carry the weight of the truck and the center section only has to turn the wheels. On an old truck, that center section has usually seen hard towing, thin or water-contaminated oil, and a leaking pinion seal at some point. Worn pinion bearings let the pinion walk forward and back under load, which moves the gear pattern and starts the howl. The early axles also lean heavily on the pilot bearing at the nose of the pinion, and a dry or pitted pilot bearing is a common find on teardown. Swapping every bearing at once and resetting the pattern with the supplied shims is what gets the axle quiet and keeps the ring and pinion alive.
Our GM 14-bolt rear axle problems guide covers the common failures and what a rebuild costs. Before you open the cover, rule out the hub bearings: a full-float hub that is loose or rough will make noise that sounds like the diff. With the rear raised, check yoke play by hand; any vertical movement means the pinion bearings are done. If you are only leaking at the axle ends, the 14-bolt axle bearing and seal kit is the part you need, not this one.
Yukon lists the YK GM14T-A for 1988-and-down GM 10.5-inch 14-bolt truck axles. Yukon splits the 14-bolt into three kits by year group because the bearings changed, so a truck built in 1989 or later needs a different kit; for 1998-up axles that is the YK GM14T-C. Do not confuse the 10.5 full-float with the smaller 14-bolt semi-float rear used under half-ton trucks; that axle takes different parts entirely. Heavy-duty trucks around the late-1980s body change can carry an axle from either side of the 1988 cutoff, so check the axle build date or send us the year and VIN. If you would rather have a Koyo-bearing kit, we also carry the ZK GM14T-A for the same axles.
| Brand | Yukon Gear & Axle |
| Part number | YK GM14T-A |
| Fits | Yukon Gear Master Overhaul Kit For GM 88 and Older 14T Diff |
| Type | Differential Overhaul Kits |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. Yukon builds separate 14-bolt kits by year group because the bearings changed. This A kit is for 1988-and-down axles. 1998-up axles take the YK GM14T-C, and the years in between have their own kit.
No. Yukon notes this kit does not come with ring gear bolts. Inspect your original bolts, and order new ones if the threads or heads are damaged. Use thread locker on them either way.
No. The half-ton 14-bolt is a smaller semi-float axle with different bearings. This kit is for the 10.5-inch full-float 14-bolt under 3/4-ton and 1-ton trucks, Suburbans and vans.
Revolution Gear's chart lists 20-35 in-lb pinion preload on new bearings and .006-.010 in. backlash for the GM 10.5, with 120 ft-lb on ring gear bolts and 135 ft-lb on bearing caps. Follow the kit instructions if they differ.
Not necessarily. Leaks at the wheel ends are hub seal leaks, fixed with the 14-bolt axle bearing and seal kit. This master kit covers the center section: carrier and pinion bearings, pilot bearing and pinion seal.
If you have gone to bigger tires or added a heavy camper, yes. The setup work is the same, so installing new gears with this kit saves paying for the labor twice.