Eaton 915A550 Detroit Truetrac Rear Differential (Fits Sterling 10.25/10.5 Axles With 35 Splines) | 1985-2016 Ford F250/F350 Super Duty 4WD

Features:

• Fits Sterling 10.25 and 10.5 rear axles
• Compatible with 35 spline axle shafts
• Works with all gear ratios
• Supports 1.5 inch axle shaft diameter
• Torque biasing limited slip for rear traction
• Uses helical gears for smooth engagement
• No clutches or wearable parts inside
• Operates automatically with no driver input
• Ideal for trucks with larger tires
• Quiet and consistent performance under load
• Heavy duty design for long-term reliability
• Fits 1985–2016 Ford F250 and F350 4WD

Traction You Can Trust Without Sacrificing Comfort

If your Super Duty is still running an open rear differential, you're missing out on one of the most practical upgrades for everyday traction. The Eaton 915A550 Detroit Truetrac is the perfect way to get consistent grip without the harshness or noise of a full locker. It reacts automatically when one wheel starts to slip, smoothly sending torque to the wheel with traction, no buttons, no switches, no driver input required. Whether you're on wet pavement, gravel, or towing through soft ground, it gives you that extra confidence without compromising on-road drivability. The Truetrac is especially useful for trucks with larger wheels and tires, where maintaining consistent traction can make or break a haul or off-road trip. Built tough and designed to last, this limited slip differential gives you all the benefits of improved control while keeping things quiet and smooth under normal conditions. It’s a smart investment that makes your truck more capable without complicating the way it drives.

Helical Gear Limited Slip Built For Sterling Axles

The Eaton 915A550 Detroit Truetrac is a torque-sensing limited slip differential designed for Sterling 10.25 and 10.5 inch axles with 35 spline shafts and a 1.5 inch axle shaft diameter. It uses a helical gear, clutch-free design to provide smooth and automatic torque biasing between the rear wheels when traction loss is detected. This makes it ideal for applications where consistent traction is needed but full locking is too aggressive, especially for daily driving or towing on mixed surfaces. The Truetrac operates quietly and requires no maintenance since there are no friction plates or clutches to wear out. It supports all gear ratios, giving flexibility for trucks that have been re-geared for performance or towing. Suitable for use in rear axle setups, this unit is built with heavy duty materials and proven engineering for long-term durability. It fits 1985–2016 Ford F250 and F350 Super Duty 4WD models equipped with the proper Sterling axle configuration. Eaton’s time-tested design provides a reliable and street-friendly way to increase rear axle performance.

Fits: 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Ford F250/F350 Super Duty 4WD

Notes:

• Only fits Sterling 10.25 and 10.5 rear axles
• Requires 35 spline axle shafts with 1.5 inch diameter
• Compatible with all gear ratios
• Designed specifically for rear axle applications
• Uses helical gear technology for torque biasing
• No clutches or friction plates to wear out
• Operates automatically without driver input
• Ideal for trucks with larger tires or towing setups
• Quiet and smooth engagement under varying conditions
• Built for durability in heavy duty applications
• Proven design with more than 60 years of field use
• Fits 1985–2016 Ford F250 and F350 Super Duty 4WD models