differential or wheel bearing?

[dannyboy]

This past winter has seemed to be the worst yet for my 06 awd. About December I noticed a low rumble/whirring noise coming from what I thought was the rear of the car. Swerved a couple times and it went away while turning right and came back when turning left. So thinking wheel bearing I had the local garage check for play when I had it in for an exhaust fix. The mechanic said the rear right wheel was going and the rear left seemed like it might soon be going. He quoted me over $700 each for rear bearings plus labor. After picking my jaw off the floor I went on ebay and found a pair of timkens for 350 taxes and shipping in for two. Because I don't have a garage I've had to wait till this pat weekend to atempt the replacement.
I decided to just replace the most likely culprit for the noise, the rear right bearing. Anyone else who owns an awd and has had to do rear bearings has my full sympathy. I used the service manual which I found on here somewhere. 8 hours later, covered in dirt, grease, sweat and some blood I got the bearing replaced. I can post pictures if anyone is interested.
long story short, I went for a test drive after I fastened everything back and what do I hear the first left turn I take but the same rumble/whirrr. My question is should I look at the differential or the front left bearing for the next most likely cause?

[lannvouivre]

I would put each end of the car on jackstands, one at a time, remove the brake hardware, and then turn the hubs and try and see if they have any play. Sometimes you can just try rocking the wheels in and out perpendicular to the axles to check for play.

The hubs should turn smoothly and silently.

Does the noise only occur while turning in a certain direction?

[dannyboy]

When I had her into the mechanic he rocked each if the hubs and determined the right rear was the furthest gone and the left rear was starting to go. He said the front were fine. This led me to replace the rear right but the noise persists. It is present driving straight at all speeds but gets louder when I turn left and quieter when I turn right. I got a good deal on a pair of front bearings on rockauto so I'm going to go ahead and replace the front right as a minimum and hope that fixes it.
As a side note, I thought I read on here somewhere that the rocking method wouldn't work on AWD rear bearings because of the differential?

[GOF]

I have always, well since they started using these sealed rollers, replaced the bearings in pairs. If one is bad the other side is likely close.

[jolt]

You may want to check this thread for troubleshooting bearing noise. You can also do a search for other threads on this subject.

viewtopic.php?f=17&t=43779

[bluneon]

let's not waste any more time and money by throwing parts at the thing or assume worst case scenario without the proper diagnosis. nothing's worse than jumping to conclusions and realizing it was never fixed.

hub play isn't an indication that the wheel bearing is going bad. there can be play in the hub, but there might not be noise/vibration. i owned a dodge shadow that had play in the DF hub but it never made noise. the principle of loading/unloading the vehicle from side-to-side isn't an accurate way to tell which side has the failing bearing; this principle should only be used to further conclude that there is bearing failure somewhere on the vehicle.

if you wish to determine the source of the noise:

since it's AWD;
safely raise and secure the vehicle until all wheels are off the ground
start the engine and place transmission into Drive
allow all 4 wheels to spin
carefully reach behind each wheel and feel the suspension spring at each corner
compare all 4 springs against each other

the spring that vibrates the most has the failing wheel bearing installed with it

[Reaccion]

You changed only one rear bearing. It is always recommended to change both of the rear bearings when one goes bad. Keep in mind that when one of the bearings gets damaged, the other one is more likely to fail as well since they were both installed the same date and they both went through the same treatment (Assuming that they were the original ones) . I actually solved my problem by buying two of the following parts at AutoZone: Timken/Wheel Bearing/Hub Assembly - Rear (Part number: HA590002). I hope that it helps!

[dannyboy]

Thanks for all the replies. I was following a friend's advice that replacing the most likely one should be fine for now. I will put her up on jacks this weekend and check the springs. As far as I know the bearings are all original, and as the car is 10 years I think I will end up doing all the bearings anyway.

I actually solved my problem by buying two of the following parts at AutoZone: Timken/Wheel Bearing/Hub Assembly - Rear (Part number: HA590002). I hope that it helps!

Those are the rear bearings I ordered first so hopefully I'm on the right track. I'll do some more diagnosing this weekend.

[Reaccion]

So, how did you do with the issue? Any updates?