Them GC Chattering noises isn't always the VC

[malmgren72]

I have taken my GC into my dealer 3 times now for the chattering problem when turning. Both previous times they had replaced the steering-something-or-other, and the last time told me that I needed to change my fluids in all my boxes. So I did, and the problem still existed. After reading this forum and talking with others, I had asssumed that the VC was at fault.

I drove into my dealer yesterday, explained the problem, and right before I finished my "whine" the dealer lady asked me "So, you think it's the VC, huh? " I said, "sure, that's what I've been told by others and my own research." So I was hoping that they were going to replace the VC and I'd be done with it. The gal told me that Chrysler makes them (the dealers) basically jump through hoops in trying to diagnose the problem before actually replacing the VC. She said that since I have had this problem for about a year and come in 3 times now, that they would probably just replace the VC and get it over with.

I called today to get a status on my GC and got some very interesting news. First, it was not the VC, it turned out to be the rear-diff that was causing the chattering noises while turning. It was explained to me that there are some gears in there that were causing the problems. The gal also told me that they DID remove the VC and then drove my GC for a bit and the noise STILL existed, and that's when they narrowed it down to the rear-diff and took it apart and found the problem.

So... They can't (chrysler says) replace the gears very easily (politics or some shite), so they are just going to replace the entire thing.. YAY!! Another thing, is that the gal checked the VC and she told me that she is aware of problems with them, but mine happened to have a certain modification to it that did not show signs of wear. She said that Chrysler probably put it in right before I bought it - August 2000.

Anyway, just thought I'd share my VC story with you all, since you've got me all worked up thinking that I'd need a new VC and even thought about getting a new TC 242, etc...

And yes, this is all under warranty.... 71K miles, with 4K left on the extended warranty. I do believe that it has paid for itself now, with this being the largest expense, along with a radiatior/water pump replacement a few months ago.

[jeeperphil]

how the !@#$ did they drive it without the vc!?!

[gtmud]

Damn good question. That just doesn't sound right, but if they are going to replace the entire rear-end under warrenty, than your in there. I will luagh my ass off if the sound is still there after all that. That gears and stuff you mentioned, unless your rear-end is a limited slip, there is not too much back there but a ring/pinion, and a set of spider gears, oh and bearings too. But I find it hard to believe, that if there was something wrong you wouldn't havve noticed it. By the way, to remove the VC requires removing and opening upthe T-case.

[xj31]

If you are driving a WJ,you don't have a viscous coupler.I think you are confused or misinformed.I'm not trying to put you down by saying that.In 99,when they came out with the WJ,they also came out with the 247 t-case.The 249 had the vc.Any ways,the 247 uses a progressive coupler.It works a little differently than the viscous.The vc is a sealed unit.Its welded shut.It basically has a fluid inside that gets very thick when it heats up.it gets heated up by the clutches inside it slipping.The progressive coupler is not sealed.it has clutches in it but it uses the t-case fluid and it actually has a pump,called a gerotor that actually produces hydraulic pressure to apply the clutches to lock the coupler.The 247 uses a different type of hydraulic fluid.When it first came out,they used atf and after a while they would shudder like a vc or even worse sometimes.Also if your jeep has quadra-drive,it has what they call vari-lock axles.Basically that means each axle has the same type of set up as the 247 t-case.Clutches and a gerotor pump in each axle.In those its very important to put the additive in the oil or it will shudder on turns.Sometimes they go bad and you have to replace it.It sounds like thats what happened.its sometimes hard to tell if its the t-case or one of the axles causing the problem.In my experience,the rear axle is the most common problem.

[malmgren72]

Originally Posted by gtmud

Damn good question. That just doesn't sound right, but if they are going to replace the entire rear-end under warrenty, than your in there. I will luagh my ass off if the sound is still there after all that. That gears and stuff you mentioned, unless your rear-end is a limited slip, there is not too much back there but a ring/pinion, and a set of spider gears, oh and bearings too. But I find it hard to believe, that if there was something wrong you wouldn't havve noticed it. By the way, to remove the VC requires removing and opening upthe T-case.

I didn't ask too many questions about HOW they removed it. I thought it was a pretty simple process of removing the driveline and the VC just slides out (with a little elbow grease, I imagine.) The noise and chattering has gone away, so if they just lied to me and replaced something else... I really don't care... that problem is fixed. The point of my post was to inform people, that the VC is not the only thing that can make the chattering noises while turning. I had believed this whole time that THAT was the problem, and it turned out it was something else. And yes, all they did was replace the gears in the rear-diff. I did ask afterwards what it would have costed without the ext-warr and she told me about 2 grand, so I'm thinking it wasn't that simple.

xj31- You may be right, but they sounded pretty sure that it had a VC in it. I even spoke to them on the phone and they mentioned it again that they removed it and test drove it. And yes, it is a quadra-drive. I wish I had thought about the rear-end being the problem a year ago when this problem started. Do you think the problem will re-occur or have they fixed it with updated parts ?

[xj31]

ok,a couple of things.Your jeep really doesnt have a vc.like I said,it's a progressive coupler.I know this for a fact because I have replaced them many times.Not as many as viscous couplers,but I have replaced them.I have worked on Jeeps for more than 17 years at 3 different Jeep dealers.Next,just because they tell you something and they sound sure,that doesn't make it true.I have listened to many service advisors B.S. customers over the years.Sometimes it's because they either don't know themselves or they think the customer won't know the difference.The part about them driving the jeep without it is kind of impossible to do.It won't move.it is pretty simple to remove,the t-case does not have to be taken out.All you need to do is pull the rear driveshaft and take off the rear retainer and there are a couple of snap rings and a bearing.It's a 15 minute job for a tech who knows what they are doing.maybe they tried a new coupler and when that wasn't it they might have put the old one back.I'm just guessing.As for the rear differential fixing it,I completely agree.The quadra drive unit is pretty expensive,I think the part alone is about $900 so 2 grand doesn't really sound out of line.That's for the internal part of the diff.It is sort of like a posi unit but instead of springs it has a pump that builds pressure and thats what applies the clutches.It comes complete.As for avoiding a repeat,just make sure that you keep the fluid changed regularly and make sure that it always has the right additive in the fluid.There is a special friction modifier and if you don't use it,it will chatter.By the way I realize you posted to inform people about something and I believe you brought up an excellent point.Especially since jeeps stopped using viscous couplers after 1998 and I know people with newer jeeps will have the same problem as you,come to this forum and possibly mis-diagnose their problem.

[Myrtle Beach]

malmgren, xj31 is correct- your vehichle doesn't have a VC. I would maybe find a Dealer that knows what they are talking about next time. Since they keep saying thats what they replaced and the WJ definately doesn't have one they are lying to you. I would go to www.wjjeeps.com and print out the information on your t-case and take it to the dealer and ask them how they replaced something your vehichle doesn't have.

[gtmud]

Question for xj31, I am working on a 94 gc full time 4x4 w/ 5.2ltr. I was going over the vehicle changing the fluids, I have read your posts and it brings up a question, in this gc's diffs, it looks like just the standard open diff front and rear, the ratio is 3.73's dana 30 frnt, and suspect chrystler rear. How can I tell if it is truely just an open diff. The ID tags are still on the diffs. Is there a certian letter/number indicating what type of diff. Also, is it safe to run Mobile One synthetic in the T-case?

[xj31]

gtmud,I don't see why mobil one would be a problem.as for the axle it should be a dana 35 in the rear of a 94.without opening it up,the easiest way to see if its an open diff is to jack up both rear wheels off the ground and try to turn one.if it turns one way and the other side goes the other way its not a trac lock(or its a worn out one)a trac lock usually has a small tag that says to use limited slip diff lube