8.8-inch 5-Lug Rear Axle Kit

The SR Performance 8.8-inch 5-lug axle kit provides a reinforced 31-spline drivetrain solution for 1999-2004 GT, Bullitt, and Mach 1 Mustangs. Designed for heavily modified or forced induction vehicles that may overwhelm factory 28-spline components, these 1541H high manganese steel alloy axles offer superior strength and durability compared to stock shafts. Each pair is induction heat-treated to handle the increased stress of high-performance street and track environments. The comprehensive kit includes both driver and passenger side axles, along with necessary bearings, seals, and studs for a complete rear-end rebuild. Please note that these axles are specifically designed for vehicles that have already upgraded to an 8.8-inch 31-spline limited-slip differential (LSD) or spool. They will not function with standard 28-spline differential units found in most factory-equipped 1979-2004 V8 Mustangs, except for the 2003-2004 SVT Cobra which came stock with 31-spline axles. Installation requires approximately 4 hours and involves significant mechanical work. Given the complexity of the drivetrain service, professional installation or advanced mechanical expertise is required for proper fitment and operation.