Ford 9in 28/31 Spline

The Ford 9in 28/31 Spline by POWERTRAX is a precision-engineered differential carrier designed for high-performance rear axle builds and heavy-duty off-road applications. This component serves as the backbone of any serious Ford 9-inch differential upgrade, enabling mechanics and enthusiasts to unlock significantly improved traction and power delivery across varied terrain. Whether you're building a drag strip competitor, a rock-crawling rig, or a street-strip hybrid, this spline configuration offers the versatility needed to match modern drivetrain demands.

The 28/31 spline designation defines the carrier's gear and side gear tooth profile, a critical specification that determines compatibility with aftermarket locker units, clutch packs, and performance differentials. POWERTRAX engineered this carrier to handle increased torque loads while maintaining precise gear mesh geometry and minimal backlash, essential characteristics for engine swaps and forced-induction applications. The compact 6.1 x 3 x 10-inch footprint and 4.45-pound weight ensure straightforward installation without requiring extensive frame modifications, while the forged construction resists the shock loads common in launch and traction-limited scenarios.

Technicians and builders working with vintage muscle cars, modern restorations, and dedicated race platforms benefit most from this carrier, particularly when pairing it with limited-slip units or spool differentials for consistent power delivery. Installation requires axle removal and carrier replacement within the third-member housing; proper torque specifications and assembly lubrication are critical to long-term reliability. Verify your existing Ford 9-inch housing matches this 28/31 spline specification before purchase, as incompatible gear ratios or carrier types will result in assembly failure and potential drivetrain damage.