BigRed93xj

Ok so I know its an all time four wheel drive. However the last couple days of driveing it I've had issues making sharp turns like into parking spots. When I have the wheel turned (not like all the way) the wheels will chirp and bounce. Like when I was in my old Cherokee in four wheel drive making a sharp turn on the street. I had a Grand previously and never had this problem.... Whats the deal, is something broken or is this usual for the all time four wheel drive Grand Cherokees?

ol"blue

It shouldn't do that. They say there's a problem with the coupler in the t-case when that happens.

Eva

How long have you had your GC? It may be your viscous coupler in your transfer case. It typically is worse when hot, on hard, dry pavement and making tight turns. The viscous coupler allows the transfer case on be AWD, without being in true 4wd unless your tires slip. When the VC goes bad (or heats up too much), it changes it from closer to a limited slip case to a serious 4wd, which, as you know, is not conducive to driving on hard, dry pavement.

You may be able to get some additional time on it with a transfer case oil change, and using a product like Lucas semi-synthetic ATF. (Double check your specs, so you put correct fluid into your case.)

I priced the VC for my 94 GC, and it looked like $400-800 for the VC only. The replacement looks pretty straightforward, but does require R&R of the transfer case. Some people have converted to a standard style part time 4WD transfer case, but I like the quadratrac for what it is. I'm personally more concerned about doing engine conversions and suspension lifts than converting the transfer case. However, some people on the forum are serious fans of the TC conversion. Again, you could possibly buy time with transfer case fluid change. I tend to start with basics, after 10 years of fleet shop ownership.

BigRed93xj

dang thats bad news. I dont know if this would contribute to that problem, but when I bought the car a couple days ago the PO had three 32x11.50 tires on and one 31x10.50 on the passenger rear side. I know thats a horrible thing to do so I already switched the tires out, but could that have caused this problem?

Eva

It wouldn't have caused the problem, but would make it more pronounced.

whowey

This certainly would contribute to the failure of the VC inside of the NP 249. The case works by detecting different wheel speeds. Different sized tires have different wheel speeds at the same MPH. With the VC being forced to work all the time, because of different wheel speeds it will wear out very quickly.

And no magic fluid is going to do anything to reverse it. Its time to either replace the VC, if you want to keep the AWD or start looking for a 242 or 231 and swap it.

BigRed93xj

isnt the np242 the better option of the two? I think Im going to swap the 242 in so I can be in two wheel drive. Total gas saver.

Chech this link out about the np249 to np242 swap:
http://www.kevinsoffroad.com/techart...-242_swap.html

oh yea and I guess I should ask the question how safe is my zj to drive? Can I still wheel with it?

whowey

Between the two AWD cases???

It certainly has more options to it. But it much harder to find in a ZJ.

The 249 is eaiser to find, but you can't switch it out of AWD mode. So if you replace the VC with a new one, you are basically resetting the timer on the problem.

The 231 doesn't have a full-time option, but it is much easier to find. It also has a great deal of aftermarket support. Which if you want to go nuts with a project is a big bonus.

BigRed93xj

the full time option is kinda pointless in my opinion... so np 231 it is. I have to get the np231 out of a grand cherokee with a v8 right. Or does it matter... Can I just grab any np231 from a cherokee?

93gc40

Have you checked the axel U-joints or cv's? Could well be the VC but your symptoms fit binding axle joints also. As for the 231 this was never available in the Grands, you will have to get it from a Wrangler or XJ. The 231 is stronger than the 242. 242 tc are more common in I6 ZJ than the AWD 247/249 TC's. The AWD TC's are more common in V8 ZJ's than I6 ZJ's. the difficult part of the 231 swap into a ZJ is Tranny output/231 TC input splines don't match, you will have to mod either the TC or Tranny. Course the 247/249 to 242 TC swap have this same issue. So be prepared for this. 231 vs 242 comes down to how you use the 4wd. If you live somewhere with weather conditions warrant STREET AWD, the 242 has big advantage, the the 231 can only be used in 4wd, on the road, in the worst conditions, ice and snow. Where the 242 can be run in 4FT in a rain storm.

BigRed93xj

Does the np242 have the full time 4wd and part time 4wd right?

lliamsdad

Your are correct

Eva

BigRed,

Whowey is correct that no magic fluid is going to fix a VC. That being said,

1) You need to complete your diagnostic work;
2) Good, fresh fluid with normal viscosities and friction additives instead of used, dirty, overworked fluid may slow the progressive wear, and give you time to complete diagnostics and confirm it *is* your VC, and not the u-joints or other components as someone else suggested; and
3) It's easy for everyone to make a diagnosis online, or at least, to say they know what it is. You're the one putting out the money and doing the work. Listen to what everyone says, and do the diagnostic work before you start replacing the TC and tearing your Cherokee apart, only to find it was something completely different. Unless, of course, you have unlimited resources and want to just replace parts.

BigRed93xj

yes very true, believe me I havent started ripping into my jeep yet. The wheel bounce or whatever you want to call it has gone away for the time being with me doing nothing to fix it. I'll eventually do a tranny flush and down the road switch in a NP 242.

Deveau

i wasnt so lucky my mechanic told me my transfer case was done and it was far too gone for the magic fluid lol. we shall see hes putting in a new one for me on monday well new to me i should say