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post #1 of 4 (permalink) Old 12-05-2017, 08:26 AM Thread Starter
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Good Morning and a Question on a 2008 XK Inspection

Hi everyone!

Nothing quite like starting off with a potentially dumb post, but here goes.

I had my eye on a 2008 XK with Quadra-Trac II. I insisted the salesman get the mud and muck washed off the bottom and then bring it up on a lift so I could check for issues. Stuff like excessive rust, driveline play, leaks and stuff like that. Anyway, while I was checking the rear differential pinion for slop, I rotated the rear driveshaft by hand and to my surprise, it moved and so did the wheels. I assume the tech put it on park before raising it up, so I was a little confused. After looking it up, it appears Quadra-Trac II has the NV245, which functions as an open differential that can electronically lock up a clutch in case of slippage. Further, both the front and rear differentials are open and use brake distribution to behave like LSDs. I think this explains why I was able to freely rotate the rear driveshaft in park, granted with some effort.

That, or I'm capable of producing 500hp with my arms. I'm thinking of buying this one, but the OCD side of me won't let go of the possibility that I damaged something. Can anyone weigh in and set my mind at ease? Thanks!
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post #2 of 4 (permalink) Old 12-05-2017, 09:48 AM
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I'm fairly new to Commanders myself, so I could be wrong here but if it was in park I don't feel like the driveshaft and both rear wheels should be spinning. If that were the case it would still roll around while parked. Did they spun freely or just a few degrees?

All I have ever owned up until this point have been solid axle jeeps. So maybe something is happening here that I am unaware of, but the only time my wheels ever spun freely while lifted were when the trans/t-case were in neutral or the front end when it was in 2wd.
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post #3 of 4 (permalink) Old 12-05-2017, 10:10 AM Thread Starter
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If 4WD - system: QT-II
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My understanding is that the transfer case being a center open differential (the viscous clutch isn't electrified/on) allows the rear driveshaft to spin. Since it's after the transmission, where the parking pawl is, I think that's normal? I was under the impression that the parking pawl only locked up the front end.
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post #4 of 4 (permalink) Old 12-05-2017, 10:20 AM
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Quote:
Originally Posted by mphilleo View Post
Hi everyone!

Nothing quite like starting off with a potentially dumb post, but here goes.

I had my eye on a 2008 XK with Quadra-Trac II. I insisted the salesman get the mud and muck washed off the bottom and then bring it up on a lift so I could check for issues. Stuff like excessive rust, driveline play, leaks and stuff like that. Anyway, while I was checking the rear differential pinion for slop, I rotated the rear driveshaft by hand and to my surprise, it moved and so did the wheels. I assume the tech put it on park before raising it up, so I was a little confused. After looking it up, it appears Quadra-Trac II has the NV245, which functions as an open differential that can electronically lock up a clutch in case of slippage. Further, both the front and rear differentials are open and use brake distribution to behave like LSDs. I think this explains why I was able to freely rotate the rear driveshaft in park, granted with some effort.

That, or I'm capable of producing 500hp with my arms. I'm thinking of buying this one, but the OCD side of me won't let go of the possibility that I damaged something. Can anyone weigh in and set my mind at ease? Thanks!
@mphilleo ;

Welcome to the forum;

Please click on the following links and read them in their entirety;

REQUIRED READING!!! Mandatory New Member Profile questions that MUST be answered.

REQUIRED READING!!! New Member Introduction post & other important new member info.

Thanks and again, welcome.

I hope everything works out and you pull the trigger on the Commander you are looking at - I posted some things to look for in your other thread - good luck!!!

Big Blue; Forum Moderator.


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Last edited by Big Blue; 12-05-2017 at 12:06 PM.
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