Ford 8.8 Simple Swap Kit – 31 Spline (Rear Axle)

Ford 8.8 Rear Axle Simple Swap — 31 Spline

Basic swap kit with plates, perches, U-bolts, and shock brackets

This kit provides the essential hardware to mount a 31-spline Ford 8.8 rear axle. It includes 3/8" A50 steel U-bolt plates with three spring-pin locations, matching spring perches, four 5/8" U-bolts (10" × 3-1/4"), and a pair of shock brackets. Components are matched so you can set center-pin position and pinion angle without sourcing parts individually.

Typical donor axles are found in Ford Explorers, F-150 trucks, and Broncos—verify tube diameter (3.25"), spring spacing, and axle width before welding. Use the three pin holes to fine-tune wheelbase, and select U-bolt length based on spring pack height and plate stack. After installation, torque U-bolts in a cross pattern and re-torque after initial miles or trail use.

Key Features

• Part Number: R1138
• For 31-spline Ford 8.8 rear axle swaps
• Plates: 3/8" A50 steel with three spring-pin positions
• Perches: matched to plates; for 3.25" axle tubes
• U-bolts: 10" length × 5/8" dia × 3-1/4" width, with 1/4" washers and nuts
• Includes pair of shock brackets

Kit Includes

• (2) Leaf spring plates, 3/8" A50 steel (three pin positions)
• (2) Spring perches (three pin positions; 3.25" tube)
• (2) Shock brackets
• (4) U-bolts, 10" × 5/8" × 3-1/4", with 1/4" laser-cut washers and nuts

Note

Confirm axle width, spring spacing, and tube diameter before welding. Choose U-bolt length that provides full thread engagement past the nut; trim excess after torque.