Axle Tech: What Do Axle Splines Do?
You hear from your buddies “in the know” who say you need at least a 33-splined axle to drive those 35-inch-tall tires. What are they talking about? Wouldn’t more splines mean less metal to hold against the torque the axle sees? We’ll be taking a quick look into axle splines and what they really translate into.
Axle splines are designed to mesh with the side spider gears and transfer the torque motion of the differential to the axle. The idea of having a spline on the axle seems contradictory considering the massive amount of torque some of the axles can see. The reality is that the splines actually are part of what makes your axle take the torque. If you look at the axle under a microscope, you’ll see that it’s not a perfect mesh.
The splines actually contact at very small portions of the splines on both the axle and the side gear. When you increase the spline count you increase the number of places that the splines make contact and increase the strength of that axle. However, is it also important to have your axle made of strong metal. Spline count won’t matter if the metal twists around and ends up looking like a piece of licorice.