Hi,

My 00 xj has a fairly loud "WWWWW" (for lack of a better discription) noise at 70 mph and over, Well to 80 anyway, I haven't had above that due to the vibration described below.

First a little filler. I bought it about 3 months ago. I don't do much e-way driving. I first noticed the noise about a month ago while on a short trip, it was accompanied by quite a vibration. I spent all day yesterday chasing down that vibration. I was told I had a bent rim. To make a short story long... It turned out to be a bad or broken belt in the tire that was causing the vibration. The tires that were on it haven't been in production for almost 4 years. Not wanting to throw an odd ball tire on and possible screwing up the drive train, I remembered, my '91 F-150(used only for Home Depot runs) uses almost identical size tires. So, I swapped the tires from one to the other.

Both the Jeep and the pick up's tires are almost new as far as tread wear goes. I've had the truck on the e-way many times above 70 with no noise. The vibration is now completely gone, but the noise remains. I'm positive it's not tire "howl." It does not change pitch or intensity with the change of speed... Unless of course I go back below 65 - 70.

Now, on top of all that... My stepson has an 89 xj 2wd that even with an aggressive tire tread is MUCH quieter and smoother than mine at speed.

So, basically ruling out tire issues, is this something that's inherent to being a 4wd model? Could it be one of the differentials? or the transfer case? Or should I just not worry about it???

I've been working a whittling this down for a month now and I've hit the wall. I'm about to reverse the logic in my signature and go ahead and have the lobotomy!

Thanks in advance,

MPH

 

mine seems to have some of that....I just thought that was normal with 4x4 turning running gear and being live axle.

Interested to see who chimes in with answers....

 

Ditto here on a 99.... I have the aggressive Dayton AT's but they still should not be this loud.... Under 65 -70 nice a quite, but above that, it is very loud.....

 

It could be a bad wheel bearing that is causing you trouble, I have that problem right now. Or possibly a tire out of balance. Ive had bad u-joints do some funky things to my jeep before. My philosophy is to let get so bad it brakes, then I know exactly whats wrong

 

How about a few simple things first...
Have you checked the fluid levels on the Tranny, Transfer Case, and Differentials? I have heard Transfer cases and Differentials that are low (usually real low) on fluid cause this noise.

Mike

 

I vote for the bad wheel bearing. I have the same wowowow coming from my right rear Chryco 8.25 rear and its the second one I put in there in a few years...Tj

 

Thanks all for the feedback,

I know it's not a wheel out of balance, all four were balanced when they were swapped. The u-joints were checked as well. As far as the fluid levels go, they were supposed to be checked by my mechanic when I had him look over the vehicle just after I bought it.

All things being equal. I can eliminate only what I know as fact. This leaves the fluid levels and bearings. Neither I or the mechanic checked the wheel bearings, and it is possible he didn't check the fluid levels or missed one. These sounds like the best place to start. I'll post what I find out.

Thanks Again & have a happy New Year!

 

I have similiar issues with my 98, not so much noise as a vibe from the right rear. I think that my r,r axle shaft has excessive runout . Brg's fluids and tires have all been ruled out. Anyone else seen this with the chryco 8.25?

 

See that bolt in the middle of the picture? I took my 44,000 mile axel in to have it the locker put in it and they found that to be loose. They think that caused slight vibrations that lead to the pinion seal having a slight leak also.
After the locker was installed I must say the axel was much quieter all the way up to 90mph.
Maybe it's something like that?
Mike

 

Thanks Mike,

Just what I wanted to do today! No garage sub freezing temps and the possibility of something like that. Seriously, you have a very good point. I'll have to find someone with a garage soon! If the levels are good, I might as well check the diff's at the same time I'm checking the wheel bearings. Gasket's are cheaper than gears!

 

Yea, sucks to not have a heated garage!
I think if it were mine I'd start with checking the Transfer Case, Front and Rear Differential fluid levels.
While I was under there I'd check the u-joints also.
If those checked out ok I'd take it for another drive and try and pinpoint the actual location of the sound. Have someone else drive so you can ride in the back seat. A great tool to finding the location of vibes is your hand. Move your hand around on the floor and see if you can pinpoint the source of the sound. ( Which should ultimately lead to the vibration that's causing the sound).
Take a look at that rear pinion seal while your under there too. From what the drive shaft shop guy said to me... is the seal can telegraph a loose preload bolt (like what I had) or a bad bearing, or I'm sure other things as well. The seal gets beat up prematurely because of the vibration. Makes sense.
I'd also try varying the throttle at your problem speeds to see what that does.
Good Luck!
Mike

 

I Googled "troubleshooting wheel bearings" and lots of info came up. Here's a link to one of them. Maybe you could Google something about vibrations or isolating vibrations, or diagnosing vibrations and find a few good tests to run.


http://jeephorizons.com/tech/axleguide.html

 

I should really check this stuff on my 90 XJ. I have had noises like this in the past but usually for different reasons and am just developing some new sounds. Noises like those at highway speeds seem to usually be a bad belt in a tire, a u-joint, wheel bearing,or in some special cases the sheet metal on the inside of your drivers door where the window motor is cracked not rusted or broke but cracked about 4 inches.

 

I was able of find the factory service manual on line. So I did some reading and set out to do some troubleshooting. But, at 10° F today. All I (My son ) was able to get done was check the fluid levels in the transfer case and differentials and inspect the drive shafts for foreign objects and possible missing weights. All that looked good so we took a suggestion from the manual and turned one of the drive shafts 180° in the yolk. This did nothing, by that time it was getting late. I'll be doing the same to the other tomorrow. I'm thinking there won't be any difference. The only thing that I can find odd so far is there are no weights on either drive shaft, and no places were it looks like their might have been a weight. Almost every drive shaft I've worked on has had a weight on it.

I can't really find anything in the manual about checking the wheel bearings other than stating that the front bearings are a sealed unit. I've always done by taking the wheel off and checking the end play. My only real experience is with 2wd cars. Fortunately, I don't have to drive long distances. If I can catch a break in the weather, or find my kerosene heater and clear enough out of the garage. I can delve a bit deeper..

Until then, I'll at least try to keep all 4 wheels attached.

 

I have the same sound on my 2001 XJ. It runs perfect and is a lot louder while in 4wheel PT. I just figured it was 'a JEEP thing'. LOL