Built for GM 8.5" and 8.6" rear axle builds, this 30-spline Grizzly Locker is a serious upgrade for trucks and rigs that need real traction under load. Whether you're working with a 10-bolt truck axle, LS swap car, or trail rig running larger tires, this locker delivers true mechanical lockupsending 100% of available torque to both axle shafts when it matters.

The upgraded tooth profile and larger internal engagement teeth increase strength and reduce the risk of failure compared to traditional designs. Built with 8620 internals and assembled in the USA, this locker is right at home in GM truck axles being pushed hardwhether thats a street-driven 10-bolt, prerunner, or a dedicated off-road build.

Includes:

• (1) GM 8.5" and 8.6" Locking differential (30-spline)
• Fully assembled internal gear set

Specifications

• Fits GM 8.5" and 8.6" differentials
• 30 spline axle compatibility
• Gear Ratio Compatibility: 2.73 and numerically higher
• Automatic mechanical locking differential
• 100% torque transfer to both wheels under load
• 8620 steel internal components
• Patented gear design for increased strength and durability
• Larger internal teeth to resist shock load and breakage
• Assembled in the USA
• Differential Cover Bolts: 10

Fitment

• Compatible with gear ratios 2.73 and up only
• Not compatible with lower (numerically higher) carrier breaks outside specified range

Tech Insight

Mechanical lockers like the Grizzly provide maximum traction by locking both axle shafts together under power. This ensures both tires receive equal torque, making it ideal for off-road and high-load applications where traction loss is common.

Unlike selectable lockers, automatic lockers engage and disengage based on load and wheel speed differences. Proper installation and setup are critical to ensure smooth operation, reduced noise, and long-term durability under aggressive driving conditions.