Crane Axle Magnum Knuckle Kit
CA01038
The Crane Magnum Knuckle System is engineered as the cornerstone of elite custom steering axles, proven worldwide in Ultra4 racing, professional rock bouncing, and hardcore rock crawling. Built to deliver maximum lateral strength and steering performance without excess weight, this modular knuckle system is designed for custom 14-Bolt, Dana 60, Dana 80, and fabricated axle housings running 40- to 47-inch tires and high-horsepower drivetrains.
Designed with professional builders and trail serviceability in mind, the Magnum Knuckle allows you to install or service RCV Big Bell CV axle shafts without removing the boot—eliminating one of the biggest maintenance headaches in off-road motorsports. Featuring top and bottom greaseable tapered roller bearings for precise kingpin preload, a 2.5-Ton Rockwell spindle bolt pattern, and support for up to 46 degrees of steering, it provides a bulletproof foundation for hardcore competition and trail builds.
Includes:
- (2) Magnum Knuckles
- (2) Inner C's
- (2) High Steer Arms
- (2) Upper Tapered Roller Bearings
- (2) Lower Tapered Roller Bearings
- (2) Upper/Lower Bearing Pins
- (2) Kingpin Caps
- Complete Hardware Kit
Made in USA
Specifications
| Specification | Details |
|---|---|
| Manufacturer | Crane Axle |
| Product Type | High-Steer Knuckle & Inner C System |
| Spindle Bolt Pattern | 2.5-Ton Rockwell |
| Kingpin Bearing Type | Dual Tapered Roller Bearings (Top & Bottom, Greaseable) |
| Inner C Bore Availability | 3.50" – 4.00" Diameter |
| Axle Shaft Compatibility | RCV Big Bell CVs (No boot removal required), RCV 40-Spline Inners, Forged 1550 U-Joints, 2.0" Axle Shafts |
| Hub / Bearing Compatibility | 2.5-Ton Rockwell Spindles & Hubs, 05+ Ford Super Duty Unit Bearings (via Crane Adapters) |
| Max Steering Angle | Up to 46° (with preferred Crane & RCV configuration) |
| Country of Origin | Made in USA |
Fitment
Designed for custom-built steering front axles in Rock Crawlers, Rock Bouncers, Ultra4 Race Cars, and Hardcore Trail Rigs running 40–47" tires.
| Application Type | Compatible Axle Housings | Compatible Spindle / Hub Setup |
|---|---|---|
| Custom Steer Axle Build | Dana 60, Dana 80, GM 14-Bolt, & Fabricated Housings (3.50"–4.00" Tube OD) | 05+ Ford Super Duty Unit Bearings (w/ Crane Adapter) |
| Custom Steer Axle Build | Dana 60, Dana 80, GM 14-Bolt, & Fabricated Housings (3.50"–4.00" Tube OD) | 2.5-Ton Rockwell Spindles & Hubs |
| Custom Steer Axle Build | Crane Axle Housings & Custom Off-Road Chassis Builds | Crane Axle Unit Bearing Adapters |
Fitment Notes
- Inner C's are available in 3.50" through 4.00" bore sizes to match your specific axle tube outside diameter. Always verify tube OD before ordering.
- Works seamlessly with all Crane Axle brake kits configured for either 2.5-Ton Rockwell or 05+ Ford Super Duty hub patterns.
- RCV Big Bell CV stub shafts pass directly through the knuckle opening without requiring CV boot removal or stretching.
FAQ
1. Why is the ability to fit RCV Big Bell shafts without removing the boot such an advantage?
On traditional aftermarket knuckles, installing or servicing an RCV CV axle shaft requires removing or stretching the protective neoprene boot, which risks tearing the boot and contaminating the CV joint with dirt and moisture. The Crane Magnum Knuckle features an enlarged opening that lets the entire RCV Big Bell assembly pass through intact, slashing maintenance and trail repair times.
2. What hub and spindle combinations can I run on the Magnum Knuckle?
The knuckles are machined with a standard 2.5-Ton Rockwell spindle bolt pattern. This allows you to bolt on factory or aftermarket 2.5-Ton Rockwell spindles and hubs, or use Crane Axle Unit Bearing Adapters to run modern 2005+ Ford Super Duty unit bearings for a maintenance-free, ultra-strong hub setup.
3. How do dual tapered roller bearings compare to standard kingpin bushings?
Factory Dana 60 kingpin setups use plastic spring-loaded upper bushings that deflect and wear rapidly under heavy off-road shock loads. The Magnum Knuckle uses top and bottom greaseable tapered roller bearings that allow you to set precise kingpin preload, eliminate steering slop, and withstand massive vertical and lateral loads from 40- to 47-inch tires. Plus, replacement bearings are readily available at standard auto parts stores.
4. How do I select the correct Inner C size for my axle housing?
The included Inner C's are bored to fit over the outside diameter (OD) of your axle tubes. Standard sizes range from 3.50" to 4.00". You should measure the exact outside diameter of your axle housing tubes before ordering to ensure a tight, weld-ready interference fit.
5. What is required to achieve the full 46 degrees of steering angle?
Achieving 46° of steering requires pairing the Magnum Knuckles with RCV Big Bell CV axle shafts, compatible steering stops, and proper steering linkage/hydraulic cylinder stroke. Traditional U-joint axle shafts will bind at lower angles, whereas the RCV CV design accommodates extreme articulation without binding.
