Horsepower always seems to find the weakest link in your driveline, and then smash it into tiny bits. One of the final stops in the driveline is the rearend itself, so it’s critical to make sure it can take the abuse you’re dishing out. For most racecars, your typical flanged-style rearend housing is fine, but if you’re really putting down big power, a full floater-style housing is a must. In this video, chassis builder Tim McAmis breaks down the difference between the two styles, and why a floater rearend is needed in high-horsepower applications.

In a rearend that uses a flanged axle, the drive flange is a part of the axle shaft itself. The bearings and axle are supporting all of the weight of the car, along with any of the extra forces that are applied on each pass. For most racing applications this is sufficient, but when you really start to apply the power this design is more prone to failure where the flange is attached to the axle.

On a floater rearend, the drive axle actually floats on the spline of the pinion and drive hub inside a spindle. There’s a drive flange on the outside of the axle that rotates the wheel as part of the hub assembly. This design allows the housing, hub, and spindle to take more of the weight or abuse, rather than the axle itself. This is much safer for big power applications and allows the axle to just help move the car forward.

Make sure you watch the entire video as McAmis gives some great insight into what makes a full floater rearend superior for big power.