What is a full floating axle and a semi floating axle?

Joe

im not exactly sure what he difference is, but this link http://www.frontrangeoffroadfab.com/floater.htm does an awesome job explaining a full floater set up

turner

The difference is that on a full floating axle, you're wheels and axle shafts are held in with a series of bolts on the hub (center of rim), you can pull the axleshaft without pulling the tire or diff cover off. On a semi-float, the axle shafts and wheels are held in with a c clip on the axleshaft, inside the pumpkin. Also, on a semi-float the weight of the truck rides directly on the axleshaft, on a full-float the weight is on the hub/wheel bearing, causing less stress on the axleshaft. I think I got it all right, correct me if I'm wrong.

1981k20- You got it right...The main advantage of a full float is that the weight of the truck is supported by the hub at the wheel and not the axleshaft. The axleshaft is only used to turn the wheels...not support the weight. Dana 44's are semi floating. Dana 70's are usually full floating. The rear hub is set up similar to a 4x4 front axle hub (the hub has 2 wheel bearings that ride on a hollow spindle which holds the axleshaft).
Full floating axles are alot stronger than semi floating axles.

Thank you.

Not all semi-float axles are c-clip axles.

Full floating axles are alot stronger than semi floating axles.
It's not that simple. FF can carry more weight but the axles ability to resist twisting failles is not what most believe.

So.. is there such thing as a semi floating front axle? Or are front axles always Full floaters?

And how do you tell the difference between any semi float vs. a full floating axle (Front or rear)?

Thanks

So.. is there such thing as a semi floating front axle? Or are front axles always Full floaters?

And how do you tell the difference between any semi float vs. a full floating axle (Front or rear)?

Thanks
All steering axles are full floating I beleive.

A FF will have a large center section sticking out past the wheel in between the lug nuts.

*Most if the information here is correct.
Like Scope said, not all semi floaters are c-cliped. Some are retained at the axle bearing. These are generall prefered over the c-clip design
All things being equal, a full floater is stronger than a semi floater. Some early Jeeps had full float Dana 44s in the rear. These are not stronger than a 35 spline semi floater Dana 60.
On a semi float axle the wheel bolts directly to the flange on the axle shaft.

It's not that simple. FF can carry more weight but the axles ability to resist twisting failles is not what most believe.


And to this add the fact that some axles are available as both semi and full float. The semi float often has a larger diameter shaft and a higher spline count. I say this because as stated above, "All things being equal, a full floater is stronger than a semi floater", all things are often not equal even in the same model axle. I prefer the full float design, but there are a number of guys out there that prefer a semifloat 60 in the rear over a full float. They might also be cheaper as a semifloat, I dunno. At least it was easy to decide on my 14bolt as the semifloat version has a smaller ring gear.

OK so "seeing how things aren't often equal" as you stated.. would you say the full floaters allow for more upgrades that would lead to a superior axle setup?



And to this add the fact that some axles are available as both semi and full float. The semi float often has a larger diameter shaft and a higher spline count. I say this because as stated above, "All things being equal, a full floater is stronger than a semi floater", all things are often not equal even in the same model axle. I prefer the full float design, but there are a number of guys out there that prefer a semifloat 60 in the rear over a full float. They might also be cheaper as a semifloat, I dunno. At least it was easy to decide on my 14bolt as the semifloat version has a smaller ring gear.

Full floating axle - axle transmits torque only bears no weight
To spot one: Look for a small circle of 8 or 10 bolts on the outside of the hub (part sticking out from wheel center, not the lug nuts), that's what's holding the axle in. You can pull the axle without even jacking the vehicle.
Common examples : any one ton dually axle, large commercial trucks
Advantages : If an axle breaks you won't die. Vehicle will still steer, roll, and brake normally.
.................................................. .................................................. ...
"Semi floating" axle - Wheel bearing is pressed onto outer end of axle, axle transmits torque AND bears weight of vehicle. Replacement axles will have the outer bearings and bearing retainers pressed on.
To spot one: end of axle doesn't stick out of wheel center, bolts mentioned above not present. Sometimes a chrome center cap will disguise a semi float rear to be full float. Most 1/2 ton pickup axles are semi-float.
Common examples:Some 14 bolts, Ford 9"
Advantages: Much lighter weight than a full float. Cheaper to manufacture than a full float. If an axle fails, the wheel will usually be retained by the pressed bearing and you'll probably live even though the vehicle will not roll or brake normally.
.................................................. .................................................. ....
C-clip axles Axle transmits torque and bears weight. Each axle is retained by a c-clip in the middle of the diff. Outer bearings are not a part of the axle assembly. Replacement axles come without bearings.
To spot one: Requires closer inspection - looks almost the same as a semi float axle to the casual observer.
Common examples Chevy 10 bolt, Chevy 12-bolt
Advantages: NONE! If an axle breaks there's nothing left holding your wheel on. Drag and Circle track racing santioning bodies will require "c-clip eliminators" in most cases on C-clip axles because of this. (they are axles that have a pressed on bearing and retainer at the end, like a traditional semi-float).

so does that mean that ff's are wider than their sf counterparts?
also what does open or closed knuckle mean?

-kit

OK so "seeing how things aren't often equal" as you stated.. would you say the full floaters allow for more upgrades that would lead to a superior axle setup?

Maybe. In the case of the 60 though, you're limited in how large of a shaft you can use by the spindle ID. Some you can bore larger for 35 spline, some you can't. Either way, it's a pita.

so does that mean that ff's are wider than their sf counterparts?
also what does open or closed knuckle mean?

-kit

The FF's generally are wider than a SF, but not always... the widest part of the SF will be the lug studs... on a FF the splined hub sticks through the wheel way past the lug studs

Open knuckle is what we see on virtually all domestic steer axles these days... Inner & outer "C"s connected by & pivoting on ball joints or kingpins, which hold a locking hub, drive flange, or unit-bearing hub... You can visually see the u-joints and axle yokes between the "C"s.

Closed knuckle is old school, the axle tube end has a hollow 'ball' on it, and the steering knuckle accepts it/seals with a round gasket/flange. The UJ is enclosed/hidden inside.

this is the dana 60 i got sittin in the backyard. ff right?
http://i6.photobucket.com/albums/y232/kitsteez/100_2686.jpg
http://i6.photobucket.com/albums/y232/kitsteez/100_2687.jpg

Yes, that is a full float axle.

Closed knuckle front.

http://4wheeloffroad.com/featuredvehicles/p74213_image_small.jpg

is a dana 60 ff as strong as a dana 70 sf? how would you go about converting an axle from closed to open knuckle?

-kit

so does that mean that ff's are wider than their sf counterparts?
also what does open or closed knuckle mean?

-kit

Not always. You can often put the hubs from a single rear wheel (SRW) full float (FF) on a dually (DRW) FF axle. This allows for some interesting measurements from wheel mount surface to wheel mount surface (WMS). It is possible to make a pretty short FF axle without actually cutting anything. Also keep in mind if you are getting your axles all from the same truck, that while the hub swap in the rear is usually pretty easy, the front axle in a DRW truck is not the same dimension as a SRW truck and will likely require modification also. Front SRW hubs for a Dana 60 are not cheap.

good info on this thread! thanks guys,