Do wheel bearings show signs of wear?

Wheel bearings are inside the wheel hub, do you plan on taking all your tires and hubs off during a pre-trip? that in itself is a few hours for this.

 

Wheel Bearing Inspection Tips

 

On a drive axle you can check the axle ends when you stop for a break. Trust me you'll know if you have one heating up. If you have reason to suspect a loose bearing you can jack the axle up and use a pry bar to check for noticable play in the wheel end.

 

Only real telltale of loose bearings during a pretrip would be a leaking wheel seal. An ABS light that won't go out can sometimes indicate loose bearings as well since the airgap at the speed sensor can be too much when the bearings are loose.

 

Good point. Twice I've discovered loose wheel bearings because I'd get an ABS light while making a turn.

 

On the steer axle or trailer axles you can check the oil for a silver colour. When you can see silver in the oil you should get it inspected as soon as practical. Most people wouldnt do it as part of the pretrip but should be done during the grease jobs. The other thing you can do do is check the hub temps if you stop for a break after driving at highway speeds. Check them as soon as you stop. They should be fairly equal in temps. If one's a lot warmer than check it out closer. You can do the same with tires too. A tire that's low on air will usually feel hotter than one at the right pressure.

 

The bearings Ive gone through are a ring inside the inside of the drive wheels. When they start going bad you will see conical bearing balls fall out one at a time until the ring follows.

Stand over your drives and lean over to where you are looking straight down the main wheel that holds both your duals. inside that wheel should be a ring bearing somewhere. If it's bad you will see it start to fall out.

We had a tractor that lost a ring bearing on a forward drive left side once. As soon I attempted that right turn into a busy Two laner, that dual tire set, wheel and axle that it was attached to started coming out to interfere with the oncoming traffic. It was out pretty much all the way when I got her onto the shoulder.

Turns out there was no way to predict bearing failure until it does fail. Generally speaking I would not have shared this story about my failed bearings if this did not actually happen one fine day. Silence in Dispatch for half an hour as they digested what happened to the tractor and what will need to be done right quick.

The only other time I ever dealt with bearings is twice, first in a vocational auto shop where i learned to pack them with red grease and install. And did a shade tree super liner 500 mack drives all 4 bearings were replaced right there in the back yard with brute power.

That's all I have. Trucking has changed from the late 70's rubber seal that you have to pull and check the level and quality of the hub oil to sealed hubs today where you might never touch the #### thing.... used to carry a quart or so in a squirt gun can to feed them hubs now and then.

 

Good article - thanks.

 

Huh???? I've never seen external wheel bearings in my life. Please explain how they receive lubrication but not be affected by the elements such as rain, snow, salt, etc.