Complete bearing and seal set for a GM 8.5 inch 10-bolt rear: Koyo carrier and pinion bearings, shims, crush sleeve, pinion seal and nut.
Owners searching for a GM 8.5 rebuild kit usually have one of three problems: a rear end that sings at 50 mph, a pinion seal that keeps leaking onto the driveshaft, or a set of new gears waiting to go in. The Motive Gear R10REMK covers all three for an 8.5 inch 10-bolt that runs an Auburn, Eaton or Grip posi. It uses Koyo tapered bearings and includes the full set of shims, seal, nut, sleeve and setup supplies, so one box gets the axle from teardown to final pattern check.
Every wear point that sets gear position lives in this kit. The pinion sits on a head bearing next to the gear and a tail bearing behind the yoke, and the crush sleeve between them sets how tightly they are loaded. The pinion depth shim sits under the head bearing race and decides how deep the pinion teeth sit in the ring gear. Out at the carrier, the two side bearings and their shims locate the ring gear left to right, which sets backlash. Motive Gear's application note for the R10REMK says it is for the GM 8.5 10-bolt with an Auburn Posi, Eaton or Grip unit, so the carrier bearings are the sizes those carriers use.
Note when the noise happens. A whine that changes between drive and coast points at the pinion side; a steady growl that follows speed points at carrier bearings or even wheel bearings. Our whine on acceleration vs deceleration diagnosis guide lays out the road test. With the axle on stands, rock the yoke to feel for play and pull the cover to look at the bearings and the gear contact pattern. If the gears themselves are chipped or badly worn, plan on gears too; our GM 8.5 and 8.6 ring and pinion buyers guide explains the options.
Motive Gear lists this kit for GM 8.5 10-bolt axles in front and rear positions, across roughly 1970 to 1999 GM cars, trucks and vans. That includes Chevrolet Camaro, Caprice, Chevelle, Monte Carlo, Nova and El Camino, C10 and K10, C1500 and K1500, Blazer, Suburban and Tahoe, GMC C/K 1500, Caballero and Yukon, plus Buick, Cadillac, Oldsmobile and Pontiac rear-drive models. The part that decides fitment is the carrier: it is listed for an 8.5 with an Auburn, Eaton or Grip posi installed. A factory open or GM posi carrier takes the standard kit, and the 8.2 and 7.5 10-bolts take different bearings altogether. Count cover bolts, check the cover outline and ring gear diameter, or send us year and VIN to match it. More kits are on our rebuild kits page. If you would rather run Timken bearings, see the R10REMKT Timken version.
Installing new gears with this kit? A GM 8.5 3.73 ring and pinion is a common match, and new gears need a gentle break-in for the first few hundred miles.
| Fits | GM 8.5 inch 10-bolt differential (1970-1999 GM applications) |
| Part number | Motive Gear R10REMK |
| Bearings | Koyo tapered carrier and pinion bearings |
| Includes | Carrier and pinion bearings, carrier and pinion shims, crush sleeve, pinion seal, pinion nut, ring gear bolts, thread locker, marking compound and brush, cover gasket or RTV |
| Condition | New |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Motive Gear lists it for the GM 8.5 10-bolt with an Auburn Posi, Eaton or Grip unit. If your axle still has the factory carrier, the standard GM 8.5 master kit is the correct choice. Check the carrier for a maker tag or casting mark before ordering.
Both carry the same application and contents list for the 8.5 with an aftermarket posi. The R10REMK uses Koyo tapered bearings and the R10REMKT uses Timken tapered bearings. Pick whichever brand you prefer; the setup procedure is the same.
Not always. If the gears show an even wear pattern with no chips or pitting, you can reuse them with new bearings, but you must set them back up to the same depth and backlash. Badly worn or noisy gears should be replaced at the same time, since you will have everything apart anyway.
Plan on a bearing puller or press for the pinion and carrier bearings, race drivers, a dial indicator with magnetic base, an inch-pound torque wrench for pinion preload, a pinion yoke holder and a large breaker bar. The marking compound and brush come in the kit.
Fill until oil reaches the bottom edge of the fill plug hole with the axle level, using 75W-90 gear oil; capacity varies by housing and year, so go by the plug rather than a fixed number. With an Auburn, Eaton or Grip posi, add the friction modifier the posi maker recommends.
