Detroit Truetrac - Ford 8in 28-Spline

The Detroit Truetrac for Ford 8-inch 28-spline differentials is a helical gear limited-slip unit engineered for drivers who demand improved traction without the harshness of a locking differential. This performance differential is ideal for trucks, SUVs, and performance vehicles running Ford 8-inch rear axles where factory open or soft-locking units compromise corner exit grip and load transfer control. Whether you're launching hard from a standstill, carving through tight track sections, or simply want more predictable power delivery off-road, the Truetrac fills the gap between sloppy open differentials and aggressive lockers that can break traction in tight turns.

Detroit's helical gear design uses a series of angled teeth that automatically bias torque toward the wheel with better grip, then seamlessly transitions back to open behavior as needed. The 28-spline input shaft mates directly with Ford 8-inch housing internals without modification, and the unit operates with minimal noise compared to locker alternatives—crucial for street and highway use. The helical geometry means smoother power transitions during load changes and reduced driveline shock, translating to longer component life and more predictable vehicle behavior in mixed-use scenarios, from spirited road driving to light off-road work or track days.

Installation requires complete differential disassembly and carrier bearing set-up, so professional shop installation is strongly recommended unless you possess dedicated gear-cutting tools and experience. This differential is compatible with all Ford 8-inch applications using 28-spline internals—including Fairmont, Ranchero, and various full-size truck platforms from the 1970s through early 1990s. The compact 9.45 × 9 × 15-inch design and 16.7-pound weight integrate seamlessly into existing housings, making it an excellent upgrade path for classic muscle, street rods, and modern performance builds seeking improved drivability without extreme aggression.