Wheel bearing or brake?

[IllmicIll]

I was driving on the highway yesterday when the car just started swerving more and more gradually but quickly got worse. It got so bad that I couldnt control the car going 20mph. I had to have the car towed. I also smelled something burning. The car has had a humming noise under power for a long time now and I was not sure what the problem was but after doing some search it seems to be a wheel bearing. (or maybe even the diff?) I pulled the car in the garage this morning to work on it and the squeaking noise was really bad. Rear right wheel is definitely the problem.

Does it sound like a brake lock up or the wheel bearing? also, how do I slide the rear caliper out to check it is not a brake lock? I pulled out the two caliper bolts but the only other remaining bolt seems to be the one that holds the brake line to the caliper. I read that theres 3 bolts total to remove but it just seems to me like that bolt is a banjo bolt and I am not about to loosen that if it is.

Thanks in advance and ASAP would be great.

 

[thepotroast]

Check that your emergency brake pads didn't come loose back there, it's a semi-common issue that pops up on these. The burning smell leads me to believe this may be the issue.

Your rear bearing is pressed into a hub assembly, so it's not the easiest or simplest job to "inspect" the bearing on these. By the time you pull the hub and have the bearing pressed out, you might as well replace it with a new unit, since everything has to be machine pressed back together.

I suspect a faulty brake assembly in the rear...based on the smell alone, not to mention the squeaking. Check your e-brakes.

 

[IllmicIll]

never even thought about that. Can you explain briefly what the e-brake assembly looks like and how to inspect it? I put the wheel back on and put the car back on the street so I can work on the hub/bearing next weekend but if it is e-brake then I can get it done today. Thanks again!

 

[thepotroast]

never even thought about that. Can you explain briefly what the e-brake assembly looks like and how to inspect it? I put the wheel back on and put the car back on the street so I can work on the hub/bearing next weekend but if it is e-brake then I can get it done today. Thanks again!

It's just the e-brake pads on the rear calipers. They sometimes deteriorate and/or break, and will stick in the rotor assembly, causing the burning smell, even smoke...and definitely noise. Needless to say it will destroy the rotor. You really need to take the rear caliper apart and inspect the pads for this.

The hub and bearing assembly is pretty straight forward, it comes out as a single assembly. You remove the circlip, have the bearing pressed out, and a new bearing pressed in. This is where it gets opinionated and situational, because you can buy the bearing by itself for the rear, and re-use the existing hub and circlip, or just buy the complete hub/bearing assembly and have the new unit pressed together. The easiest (and safest) way is to replace it all, and throw the old unit away. Not only do you only need to get the bearing pressed in (instead of the old one pressed out and a new one pressed in), which saves a little money...but also a bad bearing will wear a groove inside the hub, and putting a new bearing in a worn hub will cause quick failure.

I would suggest just replacing the entire hub/bearing assembly...parts stores sell it as 1 unit.

But before all of that, check your rear calipers...you need to pull them apart and inspect the pads.

 

[thepotroast]

Also, while you're down there....check your CV axle and boot assembly. You may have a worn CV joint in the rear, which would certainly cause some noise...and depending on the situation, the smell could be a worn boot.

The humming you describe could just be your differential whine, which is very common on 3rd gen Explorers, especially those with more than 60k miles which is the start of the sound.

I'd hate to think your problem is differential related...but who knows, these diffs and their internals are known to be quite problematic....but usually they aren't ticking time bombs.