Dumb axle question

[Farm boy]

So i have a really dumb question: what is the diff between full float, half float and such axles?

[zieg85]

First of all there are no such "dumb" questions...  A full float rear axle has the hubs sticking out where the drum has the bearings and that carries the load.  The axles are bolted to the hub and just transfer the torque where the semi float is just like the car axles where the bearings ride on the axles and carry the load.  There may be a better easier explanation but that is basically the difference.  GM opted to change to the lighter semi-float when they lightened up the trucks in 1981 and I believe only paired the full floater rears with 1 ton or 8600 GVW 3/4 ton trucks with 454 engines and diesels.  I may be off a year or two but that seems to be what I have seen.

[zieg85]

So i have a really dumb question: what is the diff between full float, half float and such axles?

The following is copied from Axle-Wikipedia

Full-floating vs semi-floating
Full-floating

The full-floating design is typically used in most 3/4 and 1-ton light trucks, medium duty trucks and heavy-duty trucks, as well as most agricultural applications, such as large tractors and combines. There are a few exceptions, such as many Land-Rover vehicles. A full-floating axle can be identified by a protruding hub to which the axle shaft flange is bolted. These axles can carry more weight than a semi-floating or non-floating axle assembly because the hubs have two bearings riding on a fixed spindle. The axle shafts themselves do not carry any weight; they serve only to transmit torque from the differential to the wheels. Full-floating axle shafts are retained by the aforementioned flange bolted to the hub, while the hub and bearings are retained on the spindle by a large nut.
Semi-floating

The semi-floating design carry the weight of the vehicle on the axle shaft itself; there is a single bearing at the end of the axle housing that carries the load from the axle and that the axle rotates through. With a semi-floating axle, the axles themselves serve as the inner bearing race and are retained by c-clips that are in the differential carrier. This design is found under most 1/2 ton and lighter trucks and SUV's.

[Irish_Alley]

also if you brake the axle shafts your tires wont fall off with full floaters