Yukon Gear Grizzly Locker For GM 10.5in 14 Bolt Truck w/ 30 Spline Axles
The full-floating GM 14-bolt is the axle people pull out of old Chevy and GMC 3/4 and 1-ton trucks, Suburbans and Express or Savana vans for big-tire builds, but with an open carrier it still spins one tire as soon as a wheel lifts. The Yukon Grizzly Locker YGLGM14T-30 is a mechanical automatic locker for the GM 10.5 inch 14-bolt truck rear with 30-spline axles. It gives both rear tires full power under load and unlocks the outside wheel in turns, without air lines or wiring.
This is not a complete carrier. The Grizzly replaces the spider gears, cross shaft and side gears inside your factory open case. Two spring-loaded couplers with clutch teeth stay meshed so both axles turn together; when one wheel needs to run faster in a turn, its coupler ratchets over and lets it overrun, then re-engages. Yukon uses 8620 internals, and its patented tooth design has a larger radius at the base of the inner clutch teeth, which Yukon rates at up to 350 percent stronger than back-cut designs and better at resisting shock-load breakage. Because it lives inside the case you already have, Yukon does not split this part by gear ratio.
Count the cover bolts and look at the pinion: the 10.5 has a 14-bolt cover and a pinion support, while the AAM 11.5 found under many 2001-and-up HD pickups looks close but takes a different locker. Our 14-bolt vs AAM 11.5 guide shows the tells, and the 14-bolt problems guide covers bearing wear to fix during the job. Then open the cover and confirm you have a factory open case with a cross shaft and four-gear spider set; the Grizzly does not go into a posi or factory locker case. If you are torn between a locker and a clutch posi, read our ELocker vs Grizzly guide.
Yukon's chart lists this part for the GM 10.5 inch 14-bolt truck rear with 30-spline axles across all four 14-bolt generations it tracks ('88-and-older, '84-'85 only, '89-'98 and '99-and-up). That includes 1973-1988 C/K and R/V 20 and 30 pickups and Suburbans, 1988-2000 C/K 2500 and 3500, 1991-2002 C3500HD, 1999-2004 Silverado and Sierra 2500, 2500 HD pickups, 2500 Suburban and Yukon XL 2500, 1996-2015 Express and Savana 2500 and 3500, G20/G30 vans, P30 chassis and the 2002-2006 Avalanche 2500. GM put both the 14-bolt and the AAM 11.5 under HD trucks in later years, so match the cover and spline count or send us your year and VIN before ordering. For the AAM axle, the Grizzly for the 11.5 is the right part. A complete carrier option for the same 14-bolt is the Detroit Locker 225S10, and the Dura Grip 4.10-down posi is the smoother street choice. More parts are in our hard parts category.
Pull the hub flange bolts and slide out the full-float axle shafts, then remove the carrier. With the case on the bench, remove the cross shaft retainer and the shaft, roll out the spider gears and take out the side gears. Yukon is clear on one point: the Grizzly does NOT use the factory thrust washers, and leaving them in makes the unit act wrong and can damage it. Assemble the locker per the Yukon instructions, reinstall the carrier with new bearings if they are worn, and set backlash to the Yukon chart range of .006-.011 inch. The Yukon 14-bolt minor install kit covers carrier bearings and shims, and a set of 4340 chromoly 30-spline axles makes sense if you are adding big tires. A locker uses plain GL-5 gear oil; it has no clutches that need friction modifier. Expect some ratcheting noise and a push in tight turns on pavement, which is normal for an automatic locker.
| Brand | Yukon Gear & Axle |
| Part number | YGLGM14T-30 |
| Fits | Yukon Gear Grizzly Locker For GM 10.5in 14 Bolt Truck w/ 30 Spline Axles |
| Type | Differentials |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. The Grizzly installs into your factory open 14-bolt case and replaces the spider gears, side gears and cross shaft. You keep your case, ring gear and bearings.
No. Yukon says the Grizzly does not use them, and leaving them in will make the locker act improperly and can damage it.
No. Because it goes inside the open case you already have, the locker works with whatever ratio that case carries.
No. This part is for the full-float GM 10.5 inch 14-bolt with 30-spline axles. The AAM 11.5 and the 9.5 need different lockers.
A standard GL-5 gear oil in the viscosity your axle calls for. There are no clutch plates, so limited slip friction modifier is not needed.
It unlocks in turns, so the truck still turns normally, but you will hear some clicking and feel a slight push in tight turns. Easy throttle in corners keeps it smooth.
