Semi floating looks like a car or F150 rear end hub, when you take a hub cap off. Full floating has a extension of the axles housing that sticks thru the center of the wheel approx 6 inches and has about 8 cap screws that hold the axle shaft in place. Hope this helps a bit. Bob:-)
>I beleive the 61 is just a light duty (for a F250) version
>of the 60 built as a semi floating. It doesn't have the full
>floating hub sticking out thru the rear wheel does it?
I have two 3.07 Dana's - one from a '77 F250 and the other from a '79 F250 - both are unquestionably full-floaters.
Semi-floating axles are identifiable by a "flat" axle flange inboard of the wheel lugs. Looks like a big car axle except with 8 lugs, and the wheel bearing is typically a straight roller bearing that rides directly on the axle shaft (axle shaft is inner race).
Full-floaters allow axle shaft removal without removing the diff cover or wheel, and use two tapered roller bearings per wheel. Advantage of a full-floating axle is should an axle shaft fail, that wheel will still hold up the vehicle.