GM 8.5in Rear Master Installation Kit

The GM 8.5in Rear Master Installation Kit is a comprehensive differential rebuild solution engineered for GM 10-bolt rear axles. Designed for mechanics and enthusiasts performing differential maintenance, upgrades, or locker installations, this master kit eliminates the guesswork of sourcing individual components. Whether you're refreshing worn bearings, installing a Detroit Locker for locking performance, or replacing seals after axle service, this kit provides every critical component needed for a professional-grade installation on the 8.5-inch GM platform.

This master installation kit from Detroit Locker-Tractech includes precision-matched bearings, crush sleeve, gaskets, OEM-spec hardware, seals, and shim stock—all engineered to restore proper differential geometry and preload. The crush sleeve ensures correct pinion bearing preload, while the gasket set maintains watertight seals against contamination. High-quality shims allow fine-tuning of backlash and gear mesh to factory tolerances, critical for eliminating noise, premature wear, and ensuring locker engagement reliability. Thread locker is included to prevent fastener vibration loosening during aggressive driving or off-road use.

Ideal for DIY builders, shops, and mechanics working on 10-bolt GM differentials found in S10 trucks, Astro vans, and performance street builds, the GM 8.5in Rear Master Installation Kit streamlines installation by consolidating scattered OEM and upgrade components into one package. Its compact 11.2 x 1.9 x 11.5-inch footprint stores easily in a toolbox. Installation requires standard differential work knowledge and basic measuring tools; proper pinion depth and backlash setup using the included shims ensures quiet operation and maximum component life. Compatible with stock and aftermarket lockers on GM 10-bolt platforms.