The Crane Axle Rear Super Duty Unit Bearing Cups are designed to simplify custom rear axle fabrication by adapting 2005+ Ford Super Duty unit bearings into fabricated rear axle housings. These weld-on cups eliminate the need for traditional rear spindles, wheel bearing packing, spindle nuts, and oil-lubricated wheel bearings, creating a cleaner and more serviceable wheel-end solution for off-road and competition applications.

Built for high-load environments such as rock crawling, Ultra4 racing, and custom buggy fabrication, this system supports large spline axle shafts while reducing many of the common maintenance and failure issues associated with traditional spindle-based rear axle setups. By using sealed unit bearings, builders can eliminate gear oil contamination concerns and avoid spindle damage caused by broken axle shafts or wheel-end deformation.

Includes:

• (2) Rear Unit Bearing Cups
• Mounting Hardware

Specifications

• Fits 2005+ Ford Super Duty unit bearings
• Weld-on rear axle cup design
• Pre-bored 3.250" inner diameter
• Can be machined to fit axle housings up to 4.00" outside diameter
• Designed for custom fabricated rear axle housings
• Compatible with large spline axle shaft applications
• Eliminates traditional rear spindle assemblies
• Made in the USA

Fitment

Fitment Notes:

• Designed for 2005+ Ford Super Duty unit bearings
• Intended for fabricated rear axle housings
• Compatible with large spline axle shaft builds
• Supports custom off-road and race axle applications
• Optional Wilwood rear brake kits available

Optional Add-Ons:

• Crane Axle Rear Unit Bearing Wilwood Lightweight Brake Kit
• Crane Axle Rear 05+ Super Duty Unit Bearing Wilwood 6 Piston Brake Kit

Tech Insight

Traditional rear spindle systems require wheel bearing preload adjustment, grease maintenance, and exposure to gear oil contamination during service. In extreme off-road environments, bent spindles and broken axle shafts can also complicate repairs and damage wheel-end components.

Using sealed Super Duty unit bearings simplifies the rear wheel-end assembly by eliminating spindle nuts and traditional wheel bearing service procedures. The compact sealed-bearing design improves maintenance accessibility while supporting larger axle shafts and high-load off-road use. This setup is especially popular in fabricated rear housings where simplicity, strength, and fast serviceability are priorities.