Axle configurations

[seabell]

I was reading the Bushrider '79 Cherokee review referred to by Panther, when I came across these terms yet again, and the time has come when I ask myself "Charlie, what are these people really talking about?"
Would someone kindly explain to this unenlightened Jeeper what is meant by "full floating" and "semi-floating" when referring to axles?

[bigfodee]

full-floating - weight of vehicle rests on bearings

semi-floating - axleshafts bear some weight

....thats all i got :D

[Panther]

Charlie,
I hope you liked the article, I thought they were pretty cool.

AFA as you question, it's pretty simple.

Have you removed your front and/or rear axle shafts?

If you notice the front outer axles shaft run through the spindle which holds the bearings the outer splines attach to the hub. That's a "full-floating" bearing set up.
The full-floating rear axles do the same thing. The purpose of this is to have both an inner and outer bearing hold the weight of the vehicle This is more advantegous for towing or carrying heavy loads.

The semi-float design is what you have in the rear 44s in your cherokees.
The shaft has a flange at the end with 6 bolt pattern studs. It has one bearing per shaft in the axle tube.

You can tell the different between the 2 a couple of ways.
Most (if not all) factory full floaters are 8 lug and you can see a hub like the front axle coming out of the rim.
A semi-floater will usually just be flat here the rim mounts. Most factory FFs don't have "manual" hubs however, like you can get in the front axle.
But in theory if you were to add rear manual hubs and had em in the front also, it would be a great anti-theif devise. Have all the hubs open and he's dumb enough to steal he's probably not smart enough to fingure that one out smile.gif
Lee

[seabell]

Ah, I'm beginning to understand.
Except that my full-floaters on my front axle(s) are six lug, I understand your explanation. I had somehow formulated the belief that these terms referred to the method of suspension attachment!
And yes, Lee, I did enjoy the article and the others mentioned in the thread. Thank you!

[seabell]

So, is there such a thing as a "non-floating" axle?

[scotty]

some axles are have the bearings pressed into the axle tubes instead of onto the shafts,and are retained by C clips,rather than 4 bolts that hold a plate thats mounted behind the pressed on bearing to the flange of the housing,like on a rear 44.

dont really know if that explanation made sense,but im pretty sure the answer to your question is "no". i believe the above examle is still a type of semi floating sahft,just alttle different method of retaiing the shafts.

im also not quite sure that to call the "sealed bearig hub assembly" in the xj/tj/yj etc. even tho it does not have a spindle,i believe it is still a full floater,cause it does have inner and outer bearings,the the center of the hub assebmly is what is supporting the weight. the stub must be present to keep the assembly pressed together, but it is not supporting any weight.

no configuration that i can think of could be considered non-floating

further questions? smile.gif

[seabell]

Thanks, Scotty.
I decided to do a quick Google to clarify Panther's explanation in my mind.
Found this:

http://www.dynatrac.com/axle_designs.html

...and this one is in Russian, but has good illustrations of the principles involved:

http://www.jeep.auto.ru/axles/float/

It appears that the terms semi- and full-floating really refer to the axle SHAFTS, yes?

[Panther]

Hey I was pretty close with my desciption (after reading the dynatrac article).

I was speaking mostly in terms on principle with the comparison with front axles and rear full floaters. The spindles, bearings and hub assemblies are different (or larger) than the front requiring the 8 lug pattern for the rims to fit around the rear hub.

I think the "floating" wold descibe both the shaft AND bearing set ups.

BUt like scotty said, I'm not sure home the C-clip axles are considered with their bearing set up.
Lee

[Sycho15]

Well- yes and no. You can't put full-floating axle-shafts into a semi-floating axle housing and have a full-floater.

Think of it this way-
With a semi-floating axle your wheel actually bolts to the end of the axle-shaft. The shaft is flanged and the wheel bolts to this flange- that is why there is no hub sticking out through the center of the rim. If your axle-shaft brakes, it can slide right out of the housing, along with the rim and tire

With a Full-floating axle, the shaft ends in the hub, to which the wheel bolts. If the shaft breaks the hub still keeps the wheel on.

Now for your homework assignment, LOL. Go to the junkyard and find 5 full-floating axles and 5 semi-floating axles. The full-floating axles will have a giant cylinder sticking out through the center-hole of the rim. That's the hub.

And... you can convert semi-floating axle housings to full-floating axle housings and then use full-floating axle shafts (shafts with splines on both ends, instead of a flange on the outer end). However- it's not simple or easy to do.