Yukon Gear Master Overhaul Kit For 2014+ GM 9.5in 12 Bolt Differential
GM's 2014-and-later half-ton trucks and full-size SUVs moved to a new 9.5 in. rear axle with a 12-bolt cover, and it is not the same axle as the 1997-2013 version even though the ring gear size matches on paper. When one of these rear ends starts howling at highway speed, growls when you pull a trailer, or leaves gear oil around the pinion, the lasting repair is fresh bearings, races and seals set up to spec. The Yukon Gear & Axle YK GM9.5-12B master overhaul kit is the new parts set for doing that on the 2014-up 9.5 in. 12-bolt.
A hypoid rear axle lives or dies by bearing preload. The pinion turns on two tapered roller bearings held in tension by a crush sleeve and nut, and the carrier spins on two side bearings whose position is fixed by shims. Together they hold the ring and pinion at the exact depth and backlash where the tooth contact pattern is centered. When the rollers and races pit or wear, preload drops, the gears shift out of their pattern and the axle gets loud, and the longer it runs that way the more it damages the gear teeth. Yukon builds this kit around Timken carrier and pinion bearings with matching races. Along with the bearings it includes the pinion seal, a complete shim kit, ring gear bolts, a new pinion nut and crush sleeve, thread locker, gear marking compound with a brush, and a cover gasket, so a setup does not stall waiting on a small part.
Put the rear axle on stands, unbolt the driveshaft and turn the pinion by hand. Grit, notches or rough spots point at the pinion bearings, and any end play means preload is already gone. Pull the cover, drain the oil and paint a few ring gear teeth with marking compound to read the contact pattern. If the teeth are clean with no pitting or chips, this overhaul kit is the repair; damaged teeth mean you need new gears as well, and Yukon's 2014-up GM 9.5 12-bolt gear set pairs with this kit. Rule out tire noise and a dry wheel bearing at the axle ends first, since both can sound like a failing differential.
This kit is listed for 2014-and-later GM 9.5 in. rear axles with the 12-bolt cover. It does not fit the 1979-1997 semi-float 9.5, which needs the YK GM9.5-A overhaul kit instead. GM also used a 9.76 in. rear axle in 2014-up trucks, mostly with the 6.2L V8, and the two look similar from under the truck. The axle size is cast into the top of the housing web on the passenger side near the pinion, so read that casting before ordering, or send us the year, engine and VIN and we will confirm. You can compare every differential and transmission rebuild kit we stock on our rebuild kits page.
Mark the original pinion depth shim and measure the old pattern before tearing down, so you have a baseline. Press the new races fully home, set pinion bearing preload by tightening the nut against the new crush sleeve in small steps, and never back the nut off once the sleeve has crushed; start over with a new sleeve if you overshoot. Use the supplied shims to set carrier preload and backlash, then confirm with marking compound before torquing the ring gear bolts with thread locker. If you are fighting crush sleeve preload or setting up new gears, the Yukon pinion install kit for the 2015-up 9.5 12-bolt is handy to have. Refill with the gear oil grade and quantity in your owner's manual, and add friction modifier only if your differential type calls for it. If you want more traction while the carrier is out anyway, the Eaton Detroit Truetrac for GM 1500 9.5 axles is an option; match its spline count and ratio range to your axle first.
| Brand | Yukon Gear & Axle |
| Part number | YK GM9.5-12B |
| Fits | Yukon Gear Master Overhaul Kit For 2014+ GM 9.5in 12 Bolt Differential |
| Type | Differential Overhaul Kits |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. This kit is for the 2014-and-later 9.5 in. axle with the 12-bolt cover. Earlier 9.5 axles use different parts, so order the kit listed for your axle's year range.
Both were used in 2014-up applications, with the 9.76 mostly paired with the 6.2L engine. The size is cast into the top of the housing web on the passenger side near the pinion. Read that casting or send us your VIN before ordering.
Yes. Along with the Timken carrier and pinion bearings and races, it includes the pinion seal, shims, ring gear bolts, a new pinion nut and crush sleeve, thread locker, marking compound and a gasket.
Yes, if the teeth are free of pitting, chips and heavy wear. Set the original pinion depth as your starting point and confirm the contact pattern with the included marking compound.
Plan on a bearing puller and press, a dial indicator for backlash, an inch-pound torque wrench for pinion preload and a way to hold the yoke while you tighten the nut against the crush sleeve.
