No your 4WD should still work. When the VC is going bad however your wheels will bind up when driving on pavement but in the mud, you'd never know if the VC was shot or not.

 

to answer the question in the thread title, drive in a few slow tight radius figure 8's and check for wheel hop or binding. try it in forward and reverse.

 

You'll need to drive until the transfercase heats up also. A stone cold start and then a couple figure 8s will prove nothing. If the VC is bad, after about 15 to 20 minutes of driving, you'll need to make a three or four point turn to make a full steering lock turn into a parking spot. The inside tire will chirp as it skips on the pavement like your fully locked up front.


Hunter

 

Mine is bad intermittantly...sometimes it will bind up when tight turning after driving for 30 minutes, other times i can drive for 5 hours straight and do figure 8's and no binding whatsoever. Im sure mine is on the way out, but it sure is taking its sweet time and actually seems like it has gotten better since i bought this thing last year.

 

Still Looking for the problem.

Thanks for all the inputs. I can definitely say it isn't the Viscous Coupler that is going bad. There is absolutely no binding between the rear drive shaft and the front driveshaft.

My next thought would be to look at the front differential. After that, I'm stumped.

 

So what did it turn out to be?

 

From the O.P.s symptoms I would look first at the front cv's. I had a similar issue and noise with mine. If you are having the same issues burrito check there first.

 

@xj93 I replaced my CV axle and the noise is gone. I'll likely switch to u-joints in the future so the boots don't get torn in the trail. Thanks for the advice!

 

I would imagine this dude has moved on..

Incase anyone searches for this and finds this thread, Ive read the VC can fail unlocked also. Ive personally never seen this or know for a fact that its true, but Ive read it.

 

On other VC based AWD systems the teeth on the VC are usually made of a softer metal so when the VC fails (locked) the teeth rip apart and you get 2wd to save wear on more expensive parts.

I've never heard of a 249 VC failing unlocked.

 

Yes like stated previous, do figure 8's when the tcase is warm. Youll be able to notice right away if the VC is bad, but your 4wd should still work. If it doesnt, you have other problems. The VC is SHOT in my 5.9 but the AWD is still beast in the snow.

 

It's more like part time now than AWD since it's locked up.

 

Its a full-time tcase

 

Yea I understand but when the VC locks up it constantly sends power to the front like in part time. That's why driving it like that on pavement messes up the front end and tires over time. It is actually better off road thought, like you said.

 

Oh yeah I just meant the 4wd was still beast after it went bad

 

I purchased a 1997 Grand Cherokee. When I purchased the vehicle it had 3 twenty's on the front and driver side, on the rear passenger side it had the stock "spare" tire (it looked like a donut compared to the twenties). When trying to get into 4 wheel drive nothing worked (btw I had the 249 case-QuadraTrac) not even in 4 LO. I tried adjusting the linkage and still only had 2wd. I was worried about the front axle being bad, but decided to tackle one issue at a time. I found a 242 transfer case (SelecTrac) in a junk yard and put it in. So far every thing is working as it should. I have 2wd, 4wd, and neutral.

I think the biggest thing most people do not know is that with the 249 transfer case- they have to keep ALL four tires within 1/4 inch roll out of each other.

And I would say that the Viscous Coupler can go completly bad to the point where it won't even be 4wd anymore.

Anyone want to purchase some twenties for their Jeep and make it a true Mall Crawler? I have all four wheels and tires now?

 

Actually Minndave even 1/4" is too much difference. As little as 3/32" difference adds up over the course of a few miles the rotational difference really compounds itself. Continued driving of that much difference adds a huge amount of stress to the VC and cuts the life expectancy down on the VC. A lot of people with AWD forget one important factor, as your p.o. did. The spare. It must match and be rotated in to keep it at the same depth to avoid issues.

 

Chrysler actually did a recall for np249 equipped vehicles that shipped with donuts.

Mismatched tires is the killer, just buying 2 tires at a time is enough to kill it. I got 185k out of mine because we kept good tread on the tires. Then I went wheeling without a matching spare, bad plan.

 

A recall for donuts? What was the repair? A bigger donut? I have the factory spare in mine still, I know it's a 16" but I couldn't tell you what it is beyond that right now.

 

The swapped donuts for full size spares.

 

If you don't rotate your full size spare in then it's going to be a larger circumference than the rest.

 

Then I still have just a donut, not that it matters I am running on 30's now and will be picking up number 5 here in a week. Need to get some straps to hold it down in the back and I'll be all good.

 

If you grab the longer bolt thing from a ZJ or XJ with a full size spare you can fit up to a 33 in the stock location.

 

Oh, thanks for the tip man. Hitting up the local pick and pull Monday so I'll keep a look out for one.

 

And that is why I like these forums!!!!! The knowledge I have gained from here is HUGE!! It was cheaper for me to switch to the 242 transfer case so that is what I did. Now I can run in two wheel drive and choose when I run in four wheel drive. As a side note: "donut" sized spare tires should only be used on two drive vehicles period!!! On four wheel drive vehicles the choice is to either fix the full size tire that went flat or buy another full size tire. Many new cars are not even coming with spares nowadays. I say carry a can of fix-a-flat and hope for the best.

Just for laughs: I had a cousin that I needed a ride from (100 miles). On the way out of the big city he stopped at the gas station and filled up the tank and then threw me the keys. The way he stated to me that I was driving made me suspicious so I asked why I was driving. You'll find out was his answer- turns out he had hit a curb months prior and had bent the front passenger wheel. The car couldn't get over 45mph!!! I inquired if the car came with a spare and he said yes but why? I pulled over to a car wash, put the spare on the rear (front wheel drive car) then put the tire that was on the rear on the front. We were able to cruise the freeway at 70 easy peazzy. He stated that if he would have known that he would have done that months prior!!!:laugh: