I apologize if this is a repeat question, however, I can't seem to find an answer to my problem here.

I have a 98 Durango 5.2 (non-LSD rear) that has road noise and neither myself nor the local mechanic can find anything wrong. Here is some background and what has been done so far:

I have had the Durango for a little over a year, the road noise was pretty significant soon after purchase. I assumed that it was the tires, so put it off until this winter when I had them replaced. The new tires cut the high speed noise in half. However, it was still there, and now I could hear a low speed sound as well. The low speed sound is more of a growl until about 20mph then it turns into a hum that increases pitch until about 50mph and then it tapers off. At 70mph the sound is pretty much gone. To me it sounds like it comes from the rear-end, however, my mechanic thinks that it’s coming from the front of the vehicle. Here is what has been done so far:
[ul][*]Changed rear diff fluid myself and replaced with synthetic. Everything looks fine in the rear end with very very little metal shavings on the magnet.[*]I have changed the load by swerving to see if it may be a wheel bearing, however, the sound does not change.[*]The front and rear brakes are in excellent shape.[*]None of the wheels are hot or even warm to the touch after a drive.[*]No leaks anywhere on the drive train.[*]No U-joint clunk[*]No 4x4 issues at all, smooth as pie.[*]No pulling or vibrations at all.[*]Mechanic replaced the front diff fluid with synthetic...........no wear or significant metal on the magnet.[*]Mechanic replaced the transfer case fluid.[*]Mechanic lifted the vehicle, spun the shafts etc. to try and find anything loose or noisy, but came up with nothing at all. In fact, he told me that everything is tight and in very good shape.[/ul]
So, here I am a few hundred dollars poorer with the same issue. The mechanic said that all he could do is tear apart the front diff and axels and start replacing bearings, however, he advised me again that all looks and feels good and that I shouldn't be concerned......

The only thing that I found here that I may try is to replace all of the U-Joints. The only other thing is that it may be a bad drive shaft?

I am planning on driving it quite a bit more this summer and I am worried about this. Any help or advice would be greatly appreciated.

Thanks, Jim

 

did you put friction modifier in thefront and rear diff when you changed the fluid?? It's a dealer only additive.

 

I used Royal Purple in the rear that had modifier in it....................however, I don't have a LSD so I assumed that I didn't need anyway.............

 

o yea I missed that part. Yea I don't think you need it.

 

if your mechanic thinks its the front end, I would check your front hub assembly....it contains the inner and outer wheel cyl., seals and bearings.....that could be an answer to your problem....

 

HOw do the front axles look? YOu didn't mention that you looked at those. Check the boots and see if they are busted, if they aren' pull them back and check the grease. Repack them and see if that helps.

Also you didn't mention what kind of tires you put on the car. If you are unable to find where the noise is coming from you could still be looking at a tire problem. Some types of tires make more noise than others. Check the tire pressure and see what they should be inflated too. Then deflate them about ten pounds and drive around a little bit to see if the noise gets worse or better. I wouldn't feel nervous about going over the stated pressure by 5psi if that makes the noise go away or lessen some.

 

Hey Guys, Thanks for the suggestions, I really appreciate it.

I looked at the CV boots and they look good, also no clunking etc. when turning so I think that they are fine.

I was surprised actually when my mechanic stated that he thought it was in the front. When I drive it, my perception is that the growling at low speeds sounds like its near the transfer case and the howling at higher speeds sounds like it is coming from the rear end............

I have Cooper Discovery ATR tires...........

So, being that I am planning to tow a small trailer this summer, I set up an appointment with one of best trans mission shops in my area (expensive, but very recommended) to have the trans flushed and a trans cooler installed. They also specialize in differentials and transfer cases so I am having this shop see if they can diagnose the road noise.

As soon as I have an update I will post..........

 

***UPDATE***


I just spoke with the head technician at the tranny shop and he confirmed my suspicions regarding the source of the road noise.......................it is indeed the rear differential contrary to what my local shop told me. It turns out that its the rear differential bearings. I plan to set up an appointment next week to have it go back for the repair. I was told that if the gears look good it will be around $400 - $450 total.

I feel better that I can diagnose the source of the noise............but it doesn't say much for the local mechanic! : (

I will post after the repair.[/align]

 

A good way to find a mechanic is by looking at the amount of business a shop brings in if they are in a more remote area. that suggests that people are willing to go a little further to get a job done right. If they are easily accessible then you just have to cross your fingers and hope unless they come highly recommended by other people that know what they are talking about with cars.

 

***UPDATE***

Just got the Durango back from the tranny shop and the road noise is gone!!! It turned out to be rear differential bearings and the pinion bearing as well. I got those replaced plus seals and a refill of synthetic lube for $450 OTD.........so I am pretty darn happy right now!

Thanks for all the help guys!