Semi-Float vs. Full-Float Axle

Semi-Float:

The most common type of rear axle is a semi-floating axle. They can be easily identified by checking pictures below. In some applications, the Air Locker that is selected will be determined by which axle is used in the vehicle. This is most common in 80 series Toyota LCs, Ford ¾ ton vans and GM ½ ton or ¾ ton pickups.

The semi-float design has the weight of the vehicle riding on the axle shaft. The axle shaft is support by wheel bearings and all of the vehicle load rides on the shaft and the wheel bearing. The axle shaft is retained by c-clips inside the differential or a bearing retainer at the flange side of the shaft (shown below).

C-Clips:

Full Float:

The full-float design has the vehicle weight riding on a wheel hub and bearing system. The axle shaft doesn’t bear any of the vehicle weight. This is considered a far more heavy duty system than a semi-float system.

The axle shaft is usually retained by a ring of bolts that connects the axle shaft to the wheel hub. In some situations, generally aftermarket, a drive flange is used to connect the axle to the wheel hub and a simple cap is used to seal it (see last picture below.)