2007 Mercury Mountaineer Whine/hum

[xpolar1]

Well my mountaineer just rolled over 115K miles, and have what I assume to be the original wheel bearings. A couple weeks ago a noise started happening around 50 mph and up, its like a hum or whine. I took it to the dealer last week, and the driver rear wheel has play in it side to side, so I know the rear wheel bearing needs to be replaced. They say go wait in the waiting room for a quote, ten minutes goes by and the guy walks in. He says you want the good or bad news. He says the wheel bearing needs to be replaced but its not your problem. Supposedly they can hear a noise in the rear diff, and that is where my problem is. I have a hard time believing the problem is in the diff. The noise is constant from 45 mph up now, and doesn't change when turning. Am I overlooking something, or is the wheel bearing causing the noise.

 

[thebrakeman]

If there is play in the bearing, change that first. See if it goes away. If there is noise in the rear diff after that, change the fluid before you let them do a rebuild. Should always do as much diagnosing as possible before you go there. You can't just drop an access plat on this rear diff. You have to pull the axle shafts and remove the rear unit to work on it. Lots of labor. Lots of money. Be sure before you let them do it.

 

[Explorer_PL]

Yep, change the bearing first, and take it from there.
use an independent shop but ask them to use Timken bearing.

After that, see if it still hums, if yes, take it to a tranny shop for more diagnostic.

 

[xpolar1]

Well I took the mountaineer into the dealer yesterday to get the drive side rear wheel bearing done, and the diff work. I was adamant with the tech that they better be sure the rear end rebuild fixes the noise, or else I'm not paying for it. Fast forward to this morning, got a call that the wheel bearing was seized and basically bonded itself to the knuckle. The guy in the service department was eating his words! Looks like the mountaineer is going to be at the dealer for the weekend