so a while ago I made a post about how I got an interesting noise under acceleration at 30 mph. I thought it had to be the rear diff, made all the symptoms of bad bearings. I replaced that axle with a used one that had been rebuilt by the previous owner, I assumed it was done correctly since he had a receipt and had miles on it before he removed it. Well that didn't fix the problem. The noise still exists in the same fashion as before, howling noise under acceleration at 30-40 mph, quieter under decceleration but still somewhat noticeable, also there is a vibration under accelerating from 15-25 mph while turning left, from what I assume is the u joints (about a 3 inch lift with no SYE). No drive train vibrations until this point. I have not been able to re-create any of these noises without the wheels on the ground. I guess that its either the transfer case or maybe I got really unlucky and got an axle with the same issue. I have a NP231 in my garage (the jeep currently has the NP242) and I have contemplated buying a SYE and swapping the T-cases but I really want to know if anyone has had similar noises from the 242 T-case. I have eliminated the front axle or front driveshaft as causes for this noise. I also did not have the U joint straps from the "new" yoke so I used the same straps from the old one, I am not sure if this is contributing to the problem. I am considering replacing the U joints but I doubt that will fix anything other than maybe the viberations.

Sounds exactly like a problem I had, but I replaced the front wheel bearings. Viola! Fixed it! I would be willing to bet it is, in fact, wheel bearings, you just got the wrong ones diagnosed

What's your pinion angle with that lift?

What's the condition of the transmission mount (mine was bad but I actually had to pull it out before I saw where it had separated)?

Not the front wheel bearings...those were replaced about a month ago

Pinion angle is stock, no shims or anything on the leafs...transmission mount looks good as far as I know but I'll check it

What is it in degrees? It's the angle of the pinion to the driveshaft. If you jacked it up 3" it won't be stock anymore:

And because the driveshaft is so short it changes a LOT when you jack it up.

Oh, I thought you meant in relation to the ground....I don't have a way of measuring it...however the jeep had been lifted for a year or so prior to having these problems so as far as the noise goes, I doubt the lift has anything to do with it. Unless the noise is coming from the transfer case...I also am going to check the fluid in it and stick some power punch black in the diff to see if the noise changes at all.

You can get a cheap pitch indicator for about 6 bucks.

https://www.homedepot.com/p/Johnson-...B&gclsrc=aw.ds

If your pinion angle is off, and especially if you spend a lot of time at highway speeds, you'll burn up U-joints.

That wouldn't cause the howling though would it? I'm more concerned about that than the u joints currently