Crane Axle GM 14-Bolt 40-Spline Spindle & Aluminum Hub Kit
CA01032-KIT
The Crane Axle GM 14-Bolt 40-Spline Spindle & Aluminum Hub Kit combines our heavy-duty 4140 chromoly rear spindles, 6061 billet aluminum wheel hubs, Timken wheel bearings, seals, spindle hardware, and spacers into one matched wheel-end package for serious 40-spline rear axle builds. Rather than adapting factory 14-Bolt wheel-end components, this system is purpose-built around the larger Crane Axle 40-spline spindle and hub configuration.
Designed for rock bouncers, competition crawlers, Ultra4 cars, high-horsepower trail rigs, and custom fabricated axles, the system increases spindle strength and axle shaft capacity while using lightweight aluminum hubs to reduce rotating and unsprung mass. The 3.00" O.D. spindle body can also be machined for smaller axle tube bores, giving builders flexibility when incorporating the system into GM 14-Bolt, Dana, or fabricated axle housings.
Includes:
- (2) Crane Axle 4140 Chromoly 40-Spline Rear Spindles
- (4) 40-Spline Spindle Nuts
- (2) Spindle Nut Retaining Dowels
- (2) Crane Axle GM 14-Bolt 40-Spline 6061 Billet Aluminum Wheel Hubs
- (2) Timken Inner Wheel Bearings & Races
- (2) Timken Outer Wheel Bearings & Races
- (2) Wheel Seals
- (2) Bearing Spacers
- (2) Bearing Retaining Snap Rings
- (2) 40-Spline Spindle Spacers
- Bearing Races Pre-Installed in Aluminum Hubs
Specifications
| Specification | Details |
|---|---|
| Manufacturer | Crane Axle |
| Axle Platform | GM 14-Bolt / Custom Fabricated Rear Axles |
| Wheel-End System | Crane Axle 40-Spline Rear Spindle System |
| Axle Shaft Spline Count | 40-Spline |
| Spindle Material | 4140 Chromoly Steel |
| Spindle Heat Treatment | Heat Treated |
| Spindle Bearing Surfaces | Precision Finish-Ground |
| Spindle Outside Diameter | 3.00" |
| Minimum Machinable Spindle Diameter | 2.00" |
| Spindle Weld Area | Extended Weld Surface |
| Hub Material | 6061 Billet Aluminum |
| Hub Finish | Machined Aluminum |
| Bearing Manufacturer | Timken |
| Bearing Type | Tapered Roller |
| Bearing Races | Included / Pre-Installed in Hubs |
| Wheel Seals | Included |
| Axle Position | Rear / Non-Steering |
| Installation Type | Custom Axle Fabrication / Assembly Required |
| Quantity | Complete Pair / Both Rear Wheel Ends |
| Manufacturing | Spindles & Hubs Machined in the USA |
Fitment
Designed For:
- Crane Axle 40-spline rear wheel-end systems
- GM 14-Bolt custom rear axle builds
- Dana 60, Dana 70, and Dana 80 custom axle builds
- Custom fabricated rear axle housings
- 40-spline axle shaft applications
- Rock bouncers and competition crawlers
- Ultra4 and race vehicles
- High-horsepower trail and off-road builds
Fitment Notes:
- Aluminum hubs are designed specifically for the Crane Axle 40-Spline Rear Spindle System
- Does not fit factory GM 14-Bolt spindles
- Does not fit standard GM 14-Bolt 30-spline spindle systems
- Standard spindle body measures 3.00" O.D.
- Spindle body can be machined to fit axle tube bores as small as 2.00"
- Wheel bearing package is specific to the Crane Axle 40-spline spindle and hub system
- Hub bearing races are included and pre-installed
- Spindles use an extended weld surface for fabricated axle housing installation
- Final axle shaft, differential, brake, housing, and wheel configuration must be verified before assembly
Additional Components Required:
- 40-spline axle shafts
- 40-spline compatible differential or spool
- Brake system
- Wheel studs and applicable wheel hardware
- Gear oil, bearing lubricant, and assembly supplies
FAQ
What is included in this 40-spline wheel-end kit?
This package combines the Crane Axle 40-spline rear spindles, matching 6061 billet aluminum wheel hubs, Timken inner and outer wheel bearings and races, wheel seals, bearing spacers, retaining snap rings, spindle nuts, retaining dowels, and 40-spline spindle spacers for both rear wheel ends.
Will these 40-spline aluminum hubs fit factory GM 14-Bolt spindles?
No. These hubs are specifically engineered to work with the Crane Axle 40-Spline Rear Spindle System. They do not fit factory GM 14-Bolt spindles or standard 30-spline 14-Bolt spindle systems.
Why does the 40-spline system use dedicated spindles?
The Crane Axle spindle is designed around the increased axle shaft capacity and wheel-end loads associated with a 40-spline axle system. The larger spindle design increases wall thickness and provides the clearance required for the matching 40-spline axle components while using an extended weld surface for fabricated axle housings.
Why use aluminum hubs with a heavy-duty 40-spline axle?
The 6061 billet aluminum hubs reduce rotating and unsprung weight compared with heavy factory-style hubs. Removing weight at the wheel end helps reduce the mass the drivetrain has to accelerate and the brakes have to slow while allowing the suspension to react more effectively.
Can the spindles be used with different axle housings?
Yes. The system is intended for custom fabricated rear axle applications, including GM 14-Bolt and custom Dana-based builds. The spindle has a standard 3.00" outside diameter and can be machined down to accommodate axle tube bores as small as 2.00". Final machining and installation must be matched to the housing being used.
Are the wheel bearings standard factory GM 14-Bolt bearings?
No. The Crane Axle 40-spline spindle system uses its own matched Timken bearing package. The included inner and outer tapered roller bearings, races, spacers, seals, and retaining components are specifically selected for the Crane 40-spline spindle and hub configuration.
Are the bearing races already installed in the hubs?
Yes. The matching bearing races are included and pre-installed in the Crane Axle aluminum wheel hubs.
Does this kit include 40-spline axle shafts?
No. Axle shafts are sold separately. Shaft length and configuration must be selected for the housing width, differential or spool, and complete axle assembly being built.
