The Eaton Detroit Locker 912A556 is a limited-slip differential built for GM 8.5 in. 10-bolt rear axles using C-clip axle retention, including standard and van configurations. It fits 28-spline axle shafts with a 1.2 in. shaft diameter and is compatible with ring gear ratios of 2.73 and up. Applications span 1971-1989 General Motors, Chevrolet, Pontiac, Buick, and Oldsmobile passenger cars, half-ton trucks, and three-quarter-ton trucks. Special carrier bearings are required: axles with a 2.89 in. race O.D. (typically pre-1999) use bearing LM102949 and race LM102911; axles with a 3.06 in. race O.D. (typically 1999-2013) use bearing LM603049 and race LM603012. Call us to confirm proper fit for your axle before ordering.
Features
GM 8.5 in. 10-bolt C-clip axle fitment, standard and van configurations
28-spline axle shaft, 1.2 in. shaft diameter
Limited-slip differential (LSD) for rear axle location
Compatible with ring gear ratios of 2.73 and up
Fits 1971-1989 GM, Chevrolet, Pontiac, Buick, and Oldsmobile passenger cars, half-ton and three-quarter-ton trucks
Special carrier bearings required - see bearing notes for small-bore (pre-1999) and large-bore axles
Tech Specs
- Ring Gear Ratio: 2.73 and up
- Differential Type: Limited Slip (LSD)
- Axle Description: GM 10-bolt C-Clip, GM 10-bolt C-Clip Van
- Axle Location: Rear
- Ring Gear Size: 8.5 in.
- Gear Spline Tooth Count: 28
- Axle Shaft Diameter: 1.2 in.
- Vehicle Make: General Motors, Chevrolet, Pontiac, Buick, Oldsmobile
- Vehicle Type: Passenger Car, Half-Ton Truck, Three Quarter-Ton Truck
- Model Year Range: 1971-1989 (start years: 1971, 1972, 1978)
- Vehicle Usage: Work Truck / Towing (on- and off-road), Light Trail / Sand Sports, Street and Muscle, Restoration, Drag Racing, Circle Track
- Bearing Note (small bore, race O.D. 2.89 in., typically pre-1999): Bearing LM102949, Race LM102911
- Bearing Note (large bore, race O.D. 3.06 in., typically 1999-2013): Bearing LM603049, Race LM603012
