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Discussion Starter #1
07 is right - you didn't state front or rear. I was assuming your problem was on the front. However, if you have Quadra Drive II, you have a full floating rear axle which means you have unit bearings on the rear as well. If you have Quadra Trac II on your XK, I believe you have a semi-floating axle which would mean you'd have to pull the axle out to replace the lug. A little more work but nothing too bad.

Not to insult you if we are second-guessing the problem, but a torque wrench is worth every penny. The lugs on the XK are good for 95 foot pounds of torque, give or take 10 pounds. Much more than that and you'll stretch the lug and it will fail. Possibly as one of them already has.
 

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07 is right - you didn't state front or rear. I was assuming your problem was on the front. However, if you have Quadra Drive II, you have a full floating rear axle which means you have unit bearings on the rear as well. If you have Quadra Trac II on your XK, I believe you have a semi-floating axle which would mean you'd have to pull the axle out to replace the lug. A little more work but nothing too bad.

Not to insult you if we are second-guessing the problem, but a torque wrench is worth every penny. The lugs on the XK are good for 95 foot pounds of torque, give or take 10 pounds. Much more than that and you'll stretch the lug and it will fail. Possibly as one of them already has.
I thought both the QD II and the QT II chrysler 8.25 rear axles were semi-floating axles. Im not saying your wrong but where did you find that out from?
 

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Discussion Starter #3 (Edited)
A while back, Ahmed found some factory information regarding the different 4wd systems for the XK. As I was reading through it, I was pleasantly surprised to see the ELSD rear axles are full floating. Snap an axle - wheel stays on! I wouldn't know where to begin to look to find that info, but Ahmed seemed to be very good at finding OEM literature as opposed to blog site reviews and third party specs. I'll look around a little.

edit - Already found something -

This is a thread from Jeepforum.com but XKPearl seems to know his stuff...

http://www.jeepforum.com/forum/showthread.php?t=308219

edit - just realized I'm sort of hijacking this - my apologies...
 

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kmax,

The info you provided on the QD II rear axle being a full floating axle is incorrect. It is a semi-floating axle, just like the chrysler 8.25 axles found in both the QT II and the QT I.
 

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I reread over that thread you posted from the jeepforum.com and a good amount of info that XKPearl wrote was in fact incorrect.
 

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Discussion Starter #6 (Edited)
I remember reading directly from Daimler-Chrysler literature that it was a full floating axle. How did you find out it's not?

The following question/answer was posted on another forum, the answer is by a factory Jeep engineer:


Quote:
Originally Posted by ArloGuthroJeep
What are the technical stats on the rear axle? What kind of suspenion geometry is it set up with?

The 4x4 Commander has a C213R (Corporate 8 1/4). The ring gear diameter is 213mm or about 8 3/8". It is a full floating design which means that the axle shaft doesn't carry the weight of the vehicle - it has a unit bearing at the wheel end. The ELSD version with QuadraDrive II has the torque capacity of a locking differential.

The suspension design is a 5-link which includes 4 control arms and a track bar.


This seems to indicate that not only is the ELSD axle a full-floater, but so is the Corp. 8.25. Tell me what I'm missing...
 

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A while back, Ahmed found some factory information regarding the different 4wd systems for the XK. As I was reading through it, I was pleasantly surprised to see the ELSD rear axles are full floating. Snap an axle - wheel stays on! I wouldn't know where to begin to look to find that info, but Ahmed seemed to be very good at finding OEM literature as opposed to blog site reviews and third party specs. I'll look around a little.

edit - Already found something -

This is a thread from Jeepforum.com but XKPearl seems to know his stuff...

http://www.jeepforum.com/forum/showthread.php?t=308219

edit - just realized I'm sort of hijacking this - my apologies...

I'm not sure where did I put that info you are referring to ! Is it this one?

http://www.jeepcommander.com/forums/showthread.php?t=5709


And we all contributed good info about the 4x4 systems in this poll http://www.jeepcommander.com/forums/showthread.php?t=4908
 

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Discussion Starter #8
Yes, Ahmed - thanks! - one of the times I read this was in jeep5253's post on 5-22-08 @ 3:55pm in your lower link there (ending in 4908). He cites the the same engineer answering the question.
 

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I remember reading directly from Daimler-Chrysler literature that it was a full floating axle. How did you find out it's not?

The following question/answer was posted on another forum, the answer is by a factory Jeep engineer:


Quote:
Originally Posted by ArloGuthroJeep
What are the technical stats on the rear axle? What kind of suspenion geometry is it set up with?

The 4x4 Commander has a C213R (Corporate 8 1/4). The ring gear diameter is 213mm or about 8 3/8". It is a full floating design which means that the axle shaft doesn't carry the weight of the vehicle - it has a unit bearing at the wheel end. The ELSD version with QuadraDrive II has the torque capacity of a locking differential.

The suspension design is a 5-link which includes 4 control arms and a track bar.


This seems to indicate that not only is the ELSD axle a full-floater, but so is the Corp. 8.25. Tell me what I'm missing...
Im not sure where that individual got that information on the rear axles being a full floating axle but he is definately incorrect. Do you guys actually know the difference between the two axles. If you did you would definately know that we dont have full floating axles in any of the XK's.

A semi-floating axles consists of an axleshaft on each side that is splined on the inner end where it mates to the differential and has a wheel flange where the wheel studs mount at the other end. This assembly typically mates to the end of the axlehousing using some type of flange arrangement. The axleshaft also rides on a large roller or ball bearing out at the end of the axlehousing. The axleshaft in a semi-floating assembly serves two purposes. First, it attaches to the wheel and is used to support the weight of the vehicle and its cargo. Second, the axleshaft must transmit the rotational torque from the differential out to the wheel.

A full-floating axle uses an axleshaft on each side that is simply splined at both ends or splined on the inner end and has a drive flange on the outer end. The shaft mates to the differential in the same way as a semi-floater. However, the outer end of the shaft differs. Here, the splined end of the shaft slides into a locking hub or an internal splined steel drive plate that bolts to a hub cap, similar to what is found on a front axle. In some cases, the drive flange may be part of the shaft itself. In either case, the axleshaft is allowed to float in the system. For a full-floater system, the axleshaft only serves to transmit the rotational torque from the differential out to the wheel. It does not carry the weight of the vehicle like a semi-floater does. On a full floater, a spindle is attached to the outer end of the axlehousing. The hub's cap is attached to this spindle and rides on tapered roller bearings. It is this assembly that carries the vehicle weight.
 

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Discussion Starter #10 (Edited)
I take it you've removed the rear rotor and you see an axle flange instead of a unit bearing? I have not removed the rear rotor so I can not say from experience. But I have known the difference in the two axle types for a little more than 24 years. My Commander is still too new - I haven't taken much of it apart yet, so I've been relying on information from others, including those I thought were qualified Jeep engineers. That Q & A session was (as I recall) from an online exchange between forum members and someone at least pretending to be a factory engineer.
 

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Yes, Ahmed - thanks! - one of the times I read this was in jeep5253's post on 5-22-08 @ 3:55pm in your lower link there (ending in 4908). He cites the the same engineer answering the question.
Im actually suprised that jeep5253 posted that information. I figured out of all people, he would know the difference between a semi-floating and full-floating axle.

On a full floating axle you can actually change out a broken axle shaft without even taking the tires off. Go out and look at your Commander and explain to me how you would go abouts doing that. Ummmm you cant since its a semi-floating axle.
 

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I take it you've removed the rear rotor and you see an axle flange instead of a unit bearing? I have not removed the rear rotor so I can not say from experience.
Sure have!
 

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We totally hi-jacked this thread. But since the OP hasnt been back since his first post I guess it doesnt matter.
 

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Discussion Starter #14
Either way, there are wheel lugs on the back axle. And sometimes those lugs break. As soon as we answer the full/semi floater question, we'll delve back into the mystery of the broken lug.

Promise.
 

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Either way, there are wheel lugs on the back axle. And sometimes those lugs break. As soon as we answer the full/semi floater question, we'll delve back into the mystery of the broken lug.

Promise.
Im pretty sure I answered the full/semi-floater question. lol

I just called the dealer and they too say its a semi-floating axle.
 

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Discussion Starter #16 (Edited)
Item #8 is a unit bearing. This is kinda fun, I still don't know who's right :)

edit - if my engineer can be wrong, so can your dealer, no?

 

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I realize that dealers arnt always correct, however this time both myself and the dealer is correct.:bowdown:
 

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This picture shows what the end of a full-floating axle looks like. The outer circle is obviously the lug nuts. The inner circle is the drive flange. If you unbolt those 8 bolts you can actually remove the axle shaft without having to take the tire off of the vehicle. This makes it very easy to swap out an axle shaft.

On the Commander you need to remove the wheel/tire, brake caliper, rotor and then unbolt the wheel hub/breaing from the axle to remove an axle shaft.

 

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Discussion Starter #20
Exactly! By your own, and the accepted definition, the axle in the commander only transfers torque, it does not carry weight. The unit bearing carries the weight. Therefore, it is a fully floating axle. It's almost worth flying to New York so you can buy me a beer :)
 
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