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what's a free-floating axle

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#1 ·
what\'s a free-floating axle

I've heard the term a couple of times but I don't know what it is. Anyone?

Blake
93 YJ/4.0L/33x12.50s/3" Rough Country suspension/1.25" shackles
 
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#2 ·
Re: what\'s a free-floating axle

One that has reached an advanced stage of enlightenment...

Just kidding. The term is full floating. There are 2 types of axles generally: Full floaters and semi-floaters.

Semi-floaters are the most common and are not as strong. In a semi-floater, there is a bearing at the end of the axlehousing that the axleshaft rides on. The wheel then bolts to the end of the axleshaft, and the axleshaft itself supports the weight of the vehicle at its end. So if you break an axleshaft, the wheel can fall off...depending where it breaks. Stock CJ, TY, YJ, XJ, and ZJ axles are all semi-floating. Ford 8.8s, amc 20s, dana 35, 44s...they all come stock as semi-floating.

A full floater has bearings at the end of the axlehousing that support a hub. THe wheel rides on the hub. So the axlehousing supports the weight...and the housing, since it is larger and heavier, is stronger than an axleshaft. THe axleshaft comes out and bolts to the end of the hub (look at a 1 ton truck or larger...inside the studs that hold the wheels on, there is a smaller ring of bolts, generally 8 or more, that bolt the axleshaft to the hub). So the axleshaft's only job is to transfer power to the wheel. It doesn't support any weight. And if an axleshaft breaks, the wheel is still fully supported by its hub and the axlehousing, so the wheel won't fall off. It's a much heavier duty setup. Another advantage is that if you need to pull the carrier, with a full floater, you don't need to take the brakes apart...you simply unbolt the axleshafts and slide them out a bit. If you need to replace an axleshaft, you can replace it without replacing all the studs/etc. that are on the end of a semi-floating axleshaft.

I Jeep, therefore I am.
 
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#3 ·
Re: what\'s a free-floating axle

When I said Hub, I didn't mean locking hub...I just meant a assembly with a bearing inside that the wheel rides on...although in some instances, you can retrofit a locking hub to the rear axle.

You can buy full-floating conversion kits for a lot of axles now...they mount a bearing on the end of the axletubes, and the wheel rides on that bearing...and then the shaft only transmits power (once again, if you break a shaft, the wheel doesn't fall off). The problem here, though, is that the axle tube (axle housing) on say an AMC 20 isn't nearly as strong as on a GM 14 bolt full-floater...and now we're transferring all the weight to the tubes, not the shaft...and since they're weak...well, you can see the problem.

I Jeep, therefore I am.
 
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#4 ·
Re: what\'s a free-floating axle

Farmjeep gave a great description. A good visual is if you can compare the 1 piece axle kits (stock diagram may help but 1 piece axle diagram would be better) to the Warn Full Floater kit for AMC 20s. After looking at the differences it made it pretty clear to me. I may have the terms wrong here but basicly the Warn kits adds a spindle to the amc 20 that supports the wheel and the axle shaft only has to work to spin the wheel. Simply put in a semi-floater the axle shaft must support the wheel and transfer the power to spin the wheel (maybe not exactly like that but general idea). While the full float has the axle shaft whose only job is to spin so essesntially it has to do less work. I don't know if this would be a real advantage or not but I would think that the full floater would have bigger bearings in comparision to a semi-float. Hope this helps some and didn't confuse you more,
David
 
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