Rear end noise

[gtosteve65]

I have a 2006 Mountaineer 4.6 V8 AWD with 150,000 on the clock. For about the past 10,000 miles its had a whining noise coming from the rear of the car. Not super audible from the front seats but its there and slightly higher pitch than a normal wheel bearing noise. In addition it seems to be worse when accelerating or decelerating.
I knew I had a bad tire (continental crap) and it was also in the rear so I blamed it on that. Moved the tire to the front and the noise traveled with it. Just got new tires and still have a noise (not as loud but same pitch, so I guess the tire was masking this noise). I already have 1 new wheel bearing on the drivers side, and from what I can tell the passenger side doesn't need one. After 10,000 miles I would expect some play from it if it were bad. Plus the tire shop didn't even say anything and you would think they would want to make some money off me. So I'm beginning to look at the rear end as the culprit. Any idea which is more likely?

Pinion Bearing.
Axle Bearing.
CV Shafts.
U-Joints (I checked and they seem fine).
Passenger side wheel bearing that has no play and seems to not make any noise when I rotate the wheel.
Gears....I hope not

Hopefully someone has had the same issue and might be able to point me in the right direction before I start ripping the car apart and changing everything in the coming weeks.

 

[07EddyB]

If you have never replaced your passenger side rear bearing I would start there - you are lucky you got 100K out of it.

 

[gtosteve65]

That will probably be my first spot to start. I got 137 out of the drivers side in the rear. I was quite impressed.

I really don't want to have to do that job if I don't have to, trying to spend as little time in my non heated garage as possible. So trying to pinpoint it better.

Tonight I plan on putting it on jackstands and putting it in gear and crawling underneath to take a listen.

 

[07EddyB]

Please be careful. It's been the consensus here that you can't really tell a bad bearing by testing for play. Some have mentioned that they can tell by holding the spring and feeling for vibrations by spinning the tire. Apparently my hands are not calibrated for that but who knows - maybe yours are. Are you feeling any vibration in the steering wheel? Oddly enough, my last rear bearing to go caused my steering wheel to shake in a very noticeable manner.
I see that you are in Long Island - buy a good kerosene heater to take the edge off of the cold in your garage. It's also a very good backup for those power outages.
I know you are trying to pinpoint it better but that bearing is due - and it looks easier to me than the rest of your options (and yes - been there done that - passenger side. Will do drivers side shortly).
Good luck man.

 

[gtosteve65]

Got underneath it about an hour ago, once my buddy let off the brake, the drivers side tire was struggling to move! The other 3 were having no issues at all. So I thought I might have a stuck e brake or bad caliper, took that off and cleaned everything up but nothing looked wrong there. So then I turned it back on and the drivers side rear is still struggling, but now so is the front passenger!! At this point I am guessing that is just a biproduct of not having limited slip and AWD. When the car is in the air only two wheels will turn for the most part. Gotta turn off traction control too or the car begins to freak out.

So now I am under the truck searching for any noises while my friend keeps her under 10mph on the jackstands. What a night...

I'll update as the night continues, but I am planning on getting a new wheel bearing for the passenger side, and maybe even a rear diff rebuild kit if they aren't too expensive.

 

[Mattre69]

gtosteve65, have you done anything with it yet? I am having similar issues, so it would be nice to know what direction to go. Mine has 192k though and had only one front and one back bearing. So, maybe I should just put the other two on it.

 

[michael loibl]

I’m at 130,000 on my 2006, and so far only replaced one front bearing just last winter. The other front is just starting to make a little noise, but I’ll wait til my wife mentions it in about 3 months when she spends more time on highways driving to the beach. Both rears are original and silent, despite lots of towing since truck was new.

 

[htsmeister]

Hi gotosteve65,

Well after all these years of reading posts and applying the learnings and solutions provided by all the time-generous members, I felt it was time to contribute after I saw your post.

I have 185k on my 2006. Had screechy squeal coming from right rear. Completely dismantled the break, cleaned, lubed the contact points and adjuster, adjusted the e-brake drum/shoe clearance, and put everything back together only to still have the same problem.

While I had everything out of the way of the hub, I rotated and rocked the hub. There was no obvious bad bearing feel as I rotated it and it didn't make any noise or have any freeplay whatsoever, so i dismissed that.

Some folks online were having trouble with u-joints, so I pulled the rear drive shaft and the joints on both ends were looser than I like, but again no freeplay, so I dismissed that.

The noise was driving me nuts. I tried swerving back and forth, applying brakes, e-brake, backing up and slamming on the brakes. Nothing modulated the sound. I went for about a 30min drive, freeway, back roads, etc. hitting bumps along the way, no change initially. However after about 30min, the noise was gone. I felt the hub and dang near burned off the end of my finger. Later, after the car sat awhile and cooled down, the noise came back. So... a heat-related issue...hmmm.

This lead me back to the hub/bearing assy. At the part of the process where I went to loosen the axle shaft nut, I was shocked to find out it was barely torqued.... no where near the 203 lb-ft it is supposed to be. maybe 50 at best. It is odd there was no freeplay (as I noted previously). Anyhow, it looks like the bearing seized up and the hub just turned inside, which was making part of the noise. I believe the other part of the (same) noise was from the bearing itself, which was in really dry and not spinning as freely as it should.

Anyhow... I have all the parts now and I am in the process of putting everything back together with super high confidence this will take care of the problem.

Good luck,

GSP

P.S. Here's a tip for anyone out there that wants to avoid damaging or destroying the backing plates once you have the spindle off. Unbolt the backing plate and let it hang loose when you put the spindle in the press. Station the press blocks between the spindle and the backing plate and press away! Another tip, I used a wire brush wheel mounted in my drill to clean out all the debris in the spindle and then pressed the bearing out. Super simple and painless. Some of the folks on u-tube had a helluva time and had to heat, cut, dremel, sawzall, etc. the bearing pieces out of their spindle!

 

[gdgiordano]

My 1997 has whine from teeth being worn in the diff. It may not be anything broken or worn out but just a rear diff on a truck suv that gets louder with age. My transmission guy says it’s very common