USA Standard Gear ZGK2004 Master Overhaul Kit for GM 8.5" Rear Differential

The USA Standard Gear ZGK2004 is a comprehensive master overhaul kit designed for GM 8.5-inch rear differentials equipped with 4.56 and higher gear ratios. This complete package includes everything needed for a professional-grade differential rebuild, combining a ring and pinion gear set, installation components, a 30-spline positraction unit, and all necessary bearings and seals.

Kit Includes:

• 4.56 ratio ring and pinion gear set for GM 8.5" rear axle
• Complete pinion installation kit with bearings, shims, and crush sleeve
• 30-spline positraction limited slip differential unit
• Carrier bearings and races
• Axle bearings for both sides
• Pinion seal and axle seals
• Marking compound and brush for proper gear pattern setup

Features and Benefits:

• Complete solution eliminates the need to source individual components
• USA Standard Gear quality ensures precise gear mesh and quiet operation
• Positraction unit provides improved traction for performance and off-road applications
• All bearings and seals included for a leak-free, professional installation
• Designed specifically for GM 8.5" 10-bolt rear axles with 30-spline axle shafts

This master kit is ideal for rebuilding worn differentials, upgrading gear ratios, or adding limited slip functionality to vehicles originally equipped with open differentials. Commonly found in GM trucks, SUVs, and performance cars including Chevrolet, GMC, Oldsmobile, and Pontiac models from the 1970s through early 2000s.