Detroit Locker 913A561 Truetrac Limited Slip Differential Ford Spline - 8.8 31

The Detroit Locker 913A561 Truetrac is a helical-gear style limited slip differential designed for Ford 8.8-inch axles with 31-spline axle shafts. This maintenance-free differential carrier provides automatic traction control without driver intervention, delivering superior performance for street, off-road, and performance applications.

Key Features:

• Helical gear design with parallel-axis planetary gears for smooth, quiet operation
• Operates as a standard open differential under normal driving conditions
• Automatically transfers up to 3.5 times more torque to the wheel with better traction
• No wearable parts, clutches, or friction modifiers required
• Forged and heat-treated case construction for maximum durability
• Compatible with all gear ratios for Ford 8.8-inch applications
• 10-bolt differential cover pattern
• Works in forward and reverse with smooth, automatic engagement

How It Works:

When a wheel loses traction, the helical-shaped gears create separation forces that redirect torque to the high-traction wheel. The gears mesh with increasing force until wheel spin is reduced or stopped, then automatically return to normal operation when traction is restored. Unlike clutch-type limited slips, the Truetrac requires no break-in period and maintains consistent performance throughout its service life.

Maintenance:

Requires only regular differential fluid changes using petroleum-based GL-5 80W90 gear oil. Do not use synthetic oils or friction modifiers, as they can reduce differential bias and overall performance.