Richmond Gear 78-7628-1 Mini Spool GM 7.625 Differential 28 Spline

The Richmond Gear 78-7628-1 is a high-performance mini spool designed for GM 7.625-inch (7.6-inch) rear differentials with 28-spline axles. This differential locking component replaces the spider gears and side gears in an open carrier, permanently locking both axles together to deliver equal power to both rear wheels for maximum traction in racing and off-road applications.

Key Features:

• CNC-machined from 4140 alloy steel forgings for superior strength and durability
• Heat-treated to aircraft standards for maximum reliability under extreme conditions
• Direct replacement for GM 7.625-inch (7.6-inch) differential applications with 28-spline axles
• Significantly easier installation than full spools—no bearing or gear setup required
• Works with existing open differential carriers (not compatible with limited-slip differentials)
• Backed by Richmond Gear's 1-year or 50,000-mile warranty
• Cross-references to Motive Gear MS7.5-28

Performance Benefits:

Mini spools eliminate wheel spin differentiation, ensuring 100% power transfer to both drive wheels at all times. This makes the 78-7628-1 an excellent choice for drag racing, dirt track racing, and dedicated competition vehicles where maximum traction is critical. Unlike welded differentials, this precision-engineered mini spool provides reliable, consistent performance without the risk of weld failure.

Installation Notes:

Installation involves removing the differential cover, draining fluid, and replacing the factory spider gears, side gears, and cross pin with the mini spool assembly. This straightforward process can typically be completed without specialized differential setup tools, making it a cost-effective alternative to full spools or limited-slip differentials.

Important Application Information:

This mini spool is recommended for racing and off-road use only. Because both wheels are permanently locked together, tire chirping will occur during cornering, and the vehicle's turning radius may be compromised. Not recommended for daily street use or vehicles operated in wet or snowy conditions.