Yukon Gear Grizzly Locker For GM 8.5in & 8.6in / 30 Spline / 2.73+
A Silverado or Sierra 1500, a Tahoe or Suburban, or a 1970s Chevelle, Camaro or Monte Carlo with a GM 10-bolt that lays down one black stripe is the classic sign of an open or worn-out carrier. The YGLGM8.5-3-30 is Yukon's Grizzly Locker for the GM 8.5 inch and 8.6 inch 10-bolt rear axles with 30-spline shafts and gear ratios of 2.73 or numerically higher. It bolts in where the factory carrier was and locks both rear wheels together automatically, with no wiring, air line or switch, so it suits trucks that tow on soft ground and street or strip cars that need both tires hooked.
The factory open carrier sends the same torque to each side, which means the axle can only push as hard as the tire with the least grip. The optional G80 locker helps, but it only engages after a wheel speed difference builds up and it is a known weak point when abused. The Grizzly replaces both with a positive mechanical design: two clutch rings with face teeth hold the 30-spline shafts together under power and on coast, and in a turn the faster outside ring ratchets free and lets that wheel overrun. Yukon specifies 8620 steel internals and a patented root profile on the inner clutch teeth that it rates at up to 350 percent stronger than back-cut lockers, and it is assembled in the USA. In a car with sticky tires or a truck backing a trailer out of a wet field, that means both tires work every time the throttle opens.
Ten cover bolts does not prove an 8.5. The GM 7.5, 7.625, 8.2, 8.5 and 8.6 all have 10-bolt covers, and the 8.2 does not share parts with this locker. Measure the ring gear or read the axle tag, then confirm 30 splines on the shafts. Our GM 8.5 and 8.6 ring and pinion guide walks through the identification and the glovebox RPO codes, including G80. For worn bearings, leaking seals and pinion wear to fix during the same job, read GM 8.5 10-bolt problems and rebuild cost. If you are undecided between a full-time and selectable unit, ELocker vs Grizzly Locker compares them.
The YGLGM8.5-3-30 is listed for GM 8.5 inch and 8.6 inch rears with 30-spline axles and 2.73-and-up gears. That covers the 8.5 in many 1970s and 1980s GM cars and half-ton trucks into the late 1990s, and the 8.6 under 1999-and-later Silverado, Sierra, Tahoe, Yukon and Suburban 1500 models. GM also used other axles in the same vehicles across the years, and some older cars came with 28-spline shafts, so a year and model alone does not settle it. Send us your year, VIN and axle tag if there is any doubt. Your ring gear moves over to the new case, and if you want to regear at the same time, the Yukon 4.88 gear set for the 8.5 and 8.6 fits this carrier. For a clutch-type option on the same axle, see the Eaton Posi for 8.5 30-spline. More carriers are listed in our hard parts category.
The 8.5 and 8.6 use C-clip retained shafts. Remove the cover, drain the oil, pull the cross shaft, push each axle in, take out the C-clips and slide the shafts out far enough to clear; then follow Yukon's instructions for C-clip retention in the Grizzly case. Transfer the ring gear with new bolts and new carrier bearings. The Grizzly case uses the large 1.781 inch bearing journal, so an older 8.5 that came with small-journal bearings needs the HD carrier bearing set (LM102949 cone, LM102911 cup) instead of its original part numbers. The master overhaul kit for 8.5s with an HD posi or locker is built around this kind of carrier, and the Timken 8.5 master overhaul kit covers standard bearing sets. Check backlash and pattern, since a new case can shift the ring gear. If a shaft is grooved at the bearing surface, replace it before it eats the new bearing. Refill with 75W-90 gear oil; the Grizzly has no clutch packs, so friction modifier is not needed. Light clicking in slow turns is normal for an automatic locker.
| Brand | Yukon Gear & Axle |
| Part number | YGLGM8.5-3-30 |
| Fits | Yukon Gear Grizzly Locker For GM 8.5in & 8.6in / 30 Spline / 2.73+ |
| 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. It is only for the 8.5 inch and 8.6 inch 10-bolt with 30-spline shafts. The 8.2, 7.5 and 7.625 look similar from behind but use different carriers.
Yes. The locker accepts 2.73 and numerically higher ratios, so common 3.08, 3.42, 3.73 and 4.10 sets bolt to it. Your ring gear moves from the old case to the Grizzly.
Yes, on an 8.5 or 8.6 with 30-spline shafts the Grizzly replaces the G80 carrier entirely. Keep the vehicle's ABS and wheel speed sensors as they are; the locker itself has no electrical parts.
A GL-5 75W-90 gear oil is the normal choice. The Grizzly is a toothed mechanical locker without clutch plates, so it does not need friction modifier.
Carrier bearings and races, the pinion seal and the cover gasket at minimum. If the pinion bearings are worn or you are regearing, buy a master overhaul kit for your 8.5 or 8.6.
