I have a 97 ZJ, 4.O, with part the time, full time and low 4WD. The other day I put it 4WD full time on a snow covered road. When I accelerated and turned I was getting a chattering noise from the front end. I did not put it in 4WD part time to see if it still chattered, I just assumed it would. I did not leave it engaged for long for fear of further damage.

So, is my 4WD shot? I have had the Jeep for a little over a year. I used the 4WD when I got to make sure it worked and I used one time in the snow last winter. So in my ownership it has seen minimal use and no problems at all when used. Is it as simple as a flush and fluid change? I guess that's the first and cheapest step in diagnosing it. Any specifc kind of fluids you guys recomend? It does have high mileage....224,00.

I had a similar problem in a 97 Mountaineer, but that was AWD, and I'm assuming a different setup. There was a chain or something in the transfer case and I guess it kept slipping which cause the chattering noise. Multiple fluid changes never fixed that one...just kept driving it as it was.

Thanks for any suggestions.

The first thing I would check is the front U-joints. I just changed mine out on my 96. All chatter went away. There a pain in the butt to change out. But if you getting chatter in the front end that is most likely the problem.

Also check the front U-joint in the front drive shaft. The geese may have dried up.

The front axle joints are CV joints, and like U joints they chatter up a storm when they fail.
So check there first for torn boots and grit and crap in them instead of grease.

I didn't think of that. Mine had U-joints. Were cv joints something they changed to for that model year?

CV's were typically found on the ZJs that have the NP249 and U-joints on the ZJs with the NP242.

Thanks for the info guys. Would these joints make this noise in just regular 2WD as well?? I'm only getting the chatter in 4WD.

I remember when i had a Wrangler I would get a thunking noise when I put it into gear and that's how I knew to change the U joints.

They might just be at the beginning stages of goin bad. If yours does have universal joints like mine eventually the needle bearings will fall out and then you'll know for sure.

This ...

I have two 98's one with CV, the other with U-Joints.

It's dependent on the T-Case.

FWIW - I got axle/CV shafts from Advanced Auto not that long ago. I think with an online discount it was like $110 for the pair.

I also put new hub assemblies on at the same time. 200K miles it was time.

ANY carden (U-joint) will cause a binding at extreme angles, especially under powered conditions. My 97 ZJ (with the 242 case) actually tossed a bearing cap. If you can afford it, replace your axles with CV joints. Well worth the investment. My WJ has them on the front driveshaft as well.

I deliver newspapers and I have to do a lot of U-turns on my route. In the interest of saving my vehicle, I've changed to K-turns instead. In the interest of saving my transmission, I don't do rolling shifts (R to D, D to R) anymore either.