New Center Section FS LW 650 Ratio 31 Spline

The PEM Center Section FS LW 650 Ratio 31 Spline is a lightweight assembled differential case engineered for Ford 9-inch applications requiring high-performance driveline durability. This steel spool differential combines a 6.50 gear ratio with 31-spline architecture, delivering the mechanical advantage needed for off-road recovery, towing operations, and high-torque driving scenarios where factory differentials fall short. The lightweight construction reduces unsprung weight while maintaining the strength demands of serious four-wheel-drive and off-road platforms.

The 6.50 ratio is engineered for maximum low-end torque multiplication, making it ideal for vehicles operating in deep terrain, rocky climbs, or situations requiring controlled high-torque power delivery. The 31-spline configuration ensures compatibility with modern Ford 9-inch axle shafts and provides superior load distribution compared to smaller spline counts. Steel spool construction locks both wheels together for absolute traction—eliminating differential slip when either wheel loses grip. The assembled unit arrives ready for installation, reducing fabrication time and labor costs on the build or rebuild.

This differential is purpose-built for operators, recovery teams, and serious enthusiasts running Ford 9-inch axles on custom off-road platforms, expedition vehicles, and high-demand work rigs. The lightweight design suits weight-conscious builds where unsprung mass impacts handling and suspension compliance. Steel spool differentials are standard in extreme environments where traction trumps on-road steering finesse, making this configuration ideal for locked-diff platforms prioritizing durability and predictable power delivery over street manners.