JFudge01

Hi everyone, I have a problem that has seemed to get worse over the last month. At first I thought maybe it was a bad steering pump but I’m not sure now, I’m thinking it could be 4wd issues.
the problem started with me hearing weird cranking noises and resistance while trying to turn, especially sharply. It would even spin the tire a bit sometimes and lurch forward when trying to make a u turn. A slight whine from the steering pump could be heard when turning, but not overly aggressive.
As of a few days ago however, there seems to be a constant noise that gets louder with what seems to be my vehicle speed, and not the rpms. It sounds like a grinding almost or a very bad exhaust leak. The car still “drives” and shifts ok so I kinda excluded the transmission or engine as culprits.
I recorded the noise and will upload here if possible, or YouTube.
Thanks in advance for any help on this issue!!!
I was gonna replace them steering pump again(I did it 4 years ago actually and still have warranty at o’Reilly) but wanted to get some opinions and insight from you all before I do so.
I had also replaced the water pump 4 years ago and that just needed replacement last month as well.

anyways, here’s my video link :

thanks again!

BlueRidgeMark

CV joints, possibly. Or front bearing. Feel the hubs when you stop after you've been driving a while.

troy69az

It sounds similar to what I just went through today on my 2000 WJ. The front end was making "ratcheting" or "cranking" noises whenever turning sharply, sometimes even "chirping" one of the front tires in a turn. It gradually got worse until it was even making some noise (not as severe though) when driving in a straight line. I crawled underneath and found my driver's side CV boot had split open and thrown out all the grease, so I replaced the CV axle assembly and installed a new hub. I went for a test drive but to my surprise the noise was still there, so today I serviced the front (Dana 30 limited-slip) differential. I sucked out some of the fluid with a transfer pump (no time to pull the cover) and replaced with Valvoline Full Syn. 75W-140 and 4oz. Mopar Limited Slip Additive. The noise is almost completely gone! My point is, a front limited-slip differential with low (or no) additive will make noises (when turning sharply) similar to a CV axle going out. The clutches in the diff are designed to slip a little when in a turn, as the outer wheel turns faster than the inner one. Without the additive, the clutches will engage (causing the differential to lock) when they shouldn't, causing the aforementioned noises. Hope this helps!

wingless

Welcome to the forum/

Which engine / transfer case?

Do all four tires match size, wear and measured outside circumference?

JFudge01

thanks for all the insight guys!
I have the 5.2 4wd model, but am unsure as to which transfer case I have. It’s a 1994, if that helps.
As to the wheels, the front two are newer and actually more aggressive.. possibly 1/2” larger than the rears. I’ve been meaning to replace the rear as well. Could that have messed something up?

wingless

You're welcome.

Yes, the mismatched tire size w/ your '94 ZJ w/ 5.2L / 46RH / NP249 cannot tolerate tires w/o identical circumference.

The viscous coupler in the early NP249 will fail, with the described symptoms, requiring replacement.

The most cost effective repair is to get a rebuilt exchange on eBay, after the tires are swapped to be identical. The swap is not horrible to perform, assuming a transmission jack is available for removing / replacing the transfer case.

This reply has links to that project. The vendor I used was STEcouplers, st3dave. His listings don't currently show the NP249, but he can probably still help.