Crane Axle 40 Spline Rear Spindle and Hub Assembly (Pair)
CA01032-KIT
Engineered for extreme abuse in rock bouncing and competition crawling, the Crane Axle 40-Spline Rear Spindle and Hub Assembly is the ultimate wheel end solution for custom 14-bolt and Dana 60/70/80 builds. This complete kit integrates precision-machined 4140 chromoly spindles with lightweight 6061 billet aluminum wheel hubs and premium Timken bearings, giving you a massive 40-spline capacity without unnecessary unsprung weight. By increasing the spindle wall thickness, this assembly dramatically improves resistance to bending and twisting under heavy torque and shock loads.
Designed specifically for custom fabricated axle housings, this pair of spindles features a heavy-duty extended weld surface for enhanced housing strength and can be machined down for compatibility with smaller axle tube bores. The included premium Timken bearing set, complete with wheel seals and heavy-duty spacers, maintains precise preload and lubrication to ensure long-term durability under aggressive traction. Replacing failure-prone factory setups, this ecosystem provides builders with everything required to assemble a competition-proven 40-spline rear end.
Specifications
| Kit Spline Count | 40-Spline |
| Spindle Material | 4140 Chromoly Steel (Heat Treated & Precision Finish-Ground) |
| Wheel Hub Material | 6061 Billet Aluminum |
| Bearings | Timken Inner & Outer Bearings with Races |
| Spindle Outer Diameter | 3.00" (Machinable down to 2.00" for custom tube bores) |
| Included Components | (2) Spindles, (2) Hubs, (4) Bearings/Races, (4) Spindle Nuts, (2) Wheel Seals, (2) Bearing Spacers, Retaining Hardware |
Fitment
| Make / Application | Axle Application |
| GM 14-Bolt Custom Builds | Rear Axle Spindle System |
| Dana 60 / 70 / 80 Custom Builds | Rear Axle Spindle System |
| Custom Off-Road Fabrications | Rear Axle Spindle System |
Fitment Notes: Designed strictly for custom fabricated rear axle applications and 40-spline axle shaft systems. The included aluminum hubs are exclusively engineered for the Crane Axle 40-Spline Spindles and will not fit factory OE spindles. Spindle O.D. may be machined for smaller axle tube bore sizes.
FAQ
1. Can I use these aluminum hubs on my factory 14-bolt spindles?
No. These billet aluminum hubs are exclusively engineered as part of the Crane Axle 40 Spline Spindle System and will not fit factory OE spindles or other aftermarket variations.
2. Why upgrade to a 40-spline wheel end over standard factory shafts?
Moving to a 40-spline system allows for much larger diameter axle shafts that can handle significantly higher torque loads and extreme shock forces found in rock bouncing and competitive crawling. This assembly provides the structural foundation necessary to support those larger shafts.
3. What is the advantage of running aluminum hubs in this setup?
6061 Billet Aluminum hubs greatly reduce unsprung and rotational mass at each corner. This translates to quicker acceleration, easier braking, and reduced overall stress on the drivetrain while retaining extreme strength against severe shock loads.
4. Can these spindles be used on axle tubes smaller than 3.00 inches?
Yes. The 4140 chromoly spindles feature a standard 3.00" outer diameter body, but the heavy-duty extended weld surface design allows them to be safely machined down by your fabricator to fit custom axle tube bores as small as 2.00".
5. Do the included bearings require any special preload setup?
Because larger 40-spline shafts place additional stress on wheel bearings, precise preload control is critical. This kit includes heavy-duty bearing spacers, genuine Timken bearings, and specific retaining hardware designed to help maintain proper bearing preload and prevent failure under extreme shock loading.