Lock Right Differential GM 8.5 78-88 28 Spline

The Lock Right Differential GM 8.5 78-88 28 Spline is a premium locking differential designed for GM vehicles equipped with 8.5-inch rear axles from 1978 through 1988. Built by POWERTRAX, a trusted manufacturer of performance drivetrain components, this locker is engineered for drivers who demand improved traction and handling in off-road, street, and motorsport applications. Whether you're tackling challenging terrain, launching hard off the line, or simply seeking better cornering grip, this differential upgrade replaces the factory open differential with a mechanical locking system that forces both rear wheels to turn at the same speed when engaged.

Constructed from durable steel and engineered for the 28-spline GM 8.5 axle platform, the Lock Right Differential employs a spring-loaded locking mechanism that automatically engages during acceleration or when traction is demanded, then unlocks smoothly during turns for conventional steering feel. The 28-spline configuration ensures proper fitment and load distribution across the differential's internal gears, while the steel construction provides long-term durability under high-stress conditions. This design eliminates wheel spin and torque bias issues inherent in open differentials, delivering consistent power delivery to both rear wheels and maximizing grip in challenging driving scenarios.

Ideal for classic muscle car enthusiasts, off-road adventurers, and performance-minded drivers with second-generation Chevrolet and GMC trucks or Camaro platforms, this locker is a bolt-in replacement for OEM differentials in 1978–1988 GM vehicles running 8.5-inch rear axles. Installation requires removing the factory differential carrier and replacing it with this assembly—a task best suited for experienced technicians or professional shops familiar with rear axle service. The compact footprint (6.2 x 3.1 x 9.7 inches) and 6.97-pound weight ensure direct compatibility without frame or suspension modifications.