The humming/whining noise is when going straight 40mph or above, while giving it gas. If I let off the throttle, the noise stops right away, soon as i hit the throttle, the noise is right there! I have to have the radio off to hear it, but still bothers me.
Sounded like the front pinion bearing to me. but it wasn't. The bearings are fine. Seal is leaking pretty good though, so new crush sleeve, and seal.
The binding or bucking, is only on turns. Thats why I figured VC for that problem. Hope so, I see their about 400 bucks. Yuk!!!

 

This same problem happened with my 94 Jeep Grand Cherokee. I couldn't figure out where it was coming from, except that it was in the front. I tightened down the pinion bolt as tight as humanly possible and the sound was way quieter and is barely noticeable. I just have to wait to get the money for a new pinion and see if this fixes it.

 

Thats what I am hoping for when he calls me when he puts it together. I am counting on him saying, "the noise is gone"!
I know this guy bought messed around with it, when he had to put a driveshaft on when he bought it. I am hoping he messed with that yoke nut. if the noise goes away with the new crush sleeve, and the proper torque...etc. I will be very happy. Then just change my VC and I am done with that part.
Of course, getting a phone call from him saying the noise is gone, is just me hoping I get lucky!

 

The buckling only happens on tight turns.
Best I can explain it, Reminds me of my 79 Bronco years ago, when I came out of the mud and felt that buckling on drive pavement on a turn. I forgot to take it out of 4WD, and "Bang", off came the front shaft...
I just read so much about the VC on these, and was thinking since I have 155K on it, it must be it. I hope so, not a cheap part!

 

Okay, my mechanic just called me. Well, the verdict is in.
The last guy I bought it off of went to the junkyard and bought a driveshaft, and installed it, and of course, "the noise started".
He just called me, and told me when he took the front shaft off, he knew it was really hard to pry off, way more than normal, but thought nothing of it. He got it all together today, and drove it with the front shaft off, and of course,
No Noise!...Go figure!
He was trying to reinstall the drive shaft on the front,
"the junkyard one, from previous owner", and said he was fighting to get it on, to the point of almost having to twist the axle.
He stopped, and called Pittsburgh Drive shaft.
They guy told him, they have three different sizes for the 96/ZJ, and of course, the one the guy got at the junkyard must have been the wrong one, not his fault really I guess.
He is running up Monday to PGH Drive shaft with my old one, and getting one that will fit right, brand new! He said that has to be the issue! he said it appears to be about 3/4's of an inch too long. I think the driveshaft place would go by my vin number??
I found this on the forum search here...
the v8 awd drive shaft with u joints is the longest one, the v8 awd with cv joint is the shortest, and the 6cyl awd or 4wd is in the middle,

I hope he is right, but he explained on the phone why it would make that noise being too long. I can't wait till Monday, and hopefully that noise is gone, and I am happy.
I guess if the noise is gone, I need to figure out if I should change the VC still. I guess if it still buckles on bends.

 

Duh...Yeah? The splined part of the shaft is bottomed out. Now why didn't I think about that? That would put incredible pressure on the pinion. I'm surprised it didn't snap something. That's overpressuring the transfer case output bearing also.

 

Honestly, I am not trying to be a wiseguy, but I would have caught that when trying to remove a drives shaft, that was stubborn coming off, buy already in collapsed position.
Well, I am sure the noise will be gone now.
I did call and educate him and tell him that the shaft that is on there, may only need 3/4's of an inch to make it on. But thats not collapsed.
But it needs more than that. I see the three sizes are inches in difference. He said he understands.
Needing 3/4's of an inch longer is not enough. He said the shaft shop will go by the year, motor, case number etc..
I should have the truck back Monday. I hope the noise is gone, and if I am really lucky, maybe I don't need a VC in the transfer case. Maybe the longer "wrong" shaft was making it buckle on turns!

 

I was just online messing around.
I am wondering what this last guy got the driveshaft off of?
I have a 1996, 4.0 automatic, with a 249 Transfer case.
Last one on the list of front drive shafts on quadratec link below.
Mine calls for the longest drive shaft out of all the ones offered, according to their measurements on the below link.

http://www.quadratec.com/jeep-replac...ive-shafts.php

 

My mechanic called and said theres nothing they can do for shortening the shaft at Greensburg Machine.
I called Greensburg Machine, he told me it sure sounds like the pinion bearings, and knows he is right, from the noise I am describing and what is doing.
He said I could have the front shaft changed over to to a ujoint style if it is too long. But he said it may be the right drive shaft, and my mechanic is a bonehead.
My mechanic said he didnt want to force it on, it was 3/4 of an inch too long.
Greensburg Machine told me the last guy got it on, and may not be the wrong one, or the cv joint would be ruined!!
He told me that pinion bearings can look fine, and not be!
He told me to bring him to him, and he would do the pinion bearings, and make the driveshaft right if it is too long, for about 800 bucks, and it will be right when it leaves there.

One more thing. Has anyone had a type 3 driveshaft, with the adjustable locknut?
Because the used one is too long that the previous guy put on, and did not adjust it. I am wondering if this is why it is making noise, maybe it needs adjusted shorter?
Manual says you should not adjust a used one?? Why is that?
I should try it before spending more money, maybe that is my problem?
Too long and putting pressure on my pinion bearing. Maybe adjusting this will eliminate the noise?
And is it possible that my mechanic is right, can you really tell if a pinion bearing and races is okay by looking at it?
Driveshaft shop said you have to cut the cage off the bearing to see if their bad, or as in open them up to know if their bad?? Well its gonna be bad if you cut it apart. I would think it is like checking old style wheel bearings? You can check them like my mechanic did, without cutting them up and ruining them.
He said mt races looked new, and the bearings were fine.




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I'm having the same problem. The jeep dealer said it was a carrier bearing in transfer case put a rebuild in still mAking the noise.