[tomynoks]

I have an '06 Commander 4.7L Front differential/transfer case is bad.. can i remove front drive line and axel halves and still drive in 2wd?

Thanks,

Tom Smith

 

[Creek]

Not from what I have read.

 

[Mongo]

The 2WD version of the Commander has a transmission with a different tail section casted into the case of the transmission. Because the end of the transmissions are different between 2WD and 4WD, because one has a XFR case bolt to it and the other has the driveshaft bolted directly to it. Think about it, that also means the 2WD versions driveshaft to the rear is longer to make up for the difference of the XFR case NOT being there.

Usually folks ask this question in reverse, Can I convert a 2WD version of a vehicle to 4WD, and the answer always turns out; you need to replace the entire drivetrain of the vehicle, the final cost will be more than what a used vehicle is worth.

Unfortunately the same is true for you; converting your 4WD to the 2WD version will require an entire replacement of the drivetrain minus the engine and rear axle. More than the cost to fix the Front drivetrain problems.

Can you disconnect the Front Drivetrain and just use the Rear Drivetrain to make it 2WD? Not without a lot of risky, expensive and unreliable modification. It also depends on the 4WD system you have.

The QTI has the simple NV140 XFR case, it has an open differential that will NOT transmit power if the front drive take-off is free-wheeling with no resistance. The vehicle likely will just sit and spin the take-off for the missing front driveshaft. (You'd have to take the XFR case apart and do some major modifications that likely will be unreliable and ultimately fail sometime down the road)

The QTII and QDII have a clutch pack inside them, "MAYBE" you could somehow trick the XFR case to engage the clutch pack and defeat the differential in the XFR case, and thus you'd be able to drive with the front driveshaft disconnected. (The clutch pack only engages normally when you are in 4WD LOW, which isn't practical for day to day driving). But, the clutch pack is designed for a much lower load of just locking two closely matched front/rear loads, NOT to transmit all the power to just one side. My guess, it would be likely to slip and burn up, leaving you stuck on the road and needing a new XFR case sometime down the road.

If you want the vehicle to drive normally and reliably, likely your cheapest option is to just repair the broken components and keep it in the configuration it is now.


***Yes, Jeep Wranglers you could do this easily, they have a totally different 4WD system than the Commander. They normally drive around in RWD only, cause the XFR case is designed to do that. Wranglers also can NOT be shifted into 4WD unless you're on a soft surface that allows the wheels to slip, while Commanders maintain 4WD for all conditions all the time.

 

[tomynoks]

Thanks for the in-depth answer. I did not know my Commander is fulltime 4wd since it has a 4wd lever near the shifter..

 

[tomynoks]

MONGO...SO if my Jeep sounds like it has a bunch of tin scraps bouncing around in it, and no 4wd, do you have an educated guess on what exactly might be wrong? Thanks, I appreciate your help...

 

[Mongo]

Thanks for the in-depth answer. I did not know my Commander is fulltime 4wd since it has a 4wd lever near the shifter..

The Commander only came with 3 different 4WD systems, and all three where Full Time 4WD. There is a lever on the QTII and QDII systems, to electrically shift into 4LOW, that is likely what you are talking about.


Its still full time 4WD, just throwing that lever activates 4LOW and locks the differential in the XFR case, for QDII it will lock the axles as well.

 

[Mongo]

MONGO...SO if my Jeep sounds like it has a bunch of tin scraps bouncing around in it, and no 4wd, do you have an educated guess on what exactly might be wrong? Thanks, I appreciate your help...

No 4WD? Do you mean if you throw the 4LOW shift lever, it will NOT shift into 4LOW and instead you get a "Service 4WD" message?


So you're getting these mechanical noises from what you suspect is from your XFR Case?


Have you drained your XFR case through a strainer to see if there is metal in it?


What little you've told us, the XFR case has mechanically failed. If that is true:


Converting it to RWD only, by removing drive shafts, will NOT work and to get it to work will cost more than just replacing the XFR Case with a new one.


The XFR case is going to need to be replaced.


I would definitely do some troubleshooting and diagnosing and NOT jump to conclusions. The CV shaft or U-joints to the driveshafts going to the XFR case could be bad and making these noises, and you've misidentified them.


If the XFR case is sounding like its grind rocks inside it, and it is the XFR Case making the noise, there will be metal in fluid as you drain it. CV shafts and u-joints can sound like they are grinding rocks as well. Cheaper and easier to replace. (although the rear driveshaft does NOT have serviceable u-joints, you have to replace the entire driveshaft). Even bad wheel bearings, not so uncommon on the Commander could be making these noises.


As well, the "Service 4WD" message can come up for perfectly good XFR case because of bad software loaded from a recall. The latest updated software fixes the erroneous misidentification and disabling of a bad XFR Case that is actually good.

 

[tomynoks]

Good info!!! THANKS!! YES I get the "SERVICE 4WD" message when I try to throw the 4LOW shift lever. YES I need to do more checking to see exactly what's going on...

Thanks again!!

 

[Mongo]

Putting the vehicle up on jackstands, so all 4 wheels are off the ground, and running the wheels in drive at engine idle, would help to look over the drivetrain to find the noise. Be careful obviously, if you got something caught in the turning parts it could be fatal.


Putting a section of broom stick up against parts and putting your ear against the broom stick acts like a stethoscope. It really does work, and when you have noise that you can't track down exactly which part its coming from, you can certainly tell with the broomstick trick. Pressed up against parts that make a little noise, then you press it up against the bad part, you'll hear a real racket being created by the part. Again, outmost caution pressing this up against moving parts.