Cleaning and checking wheel bearings.

[johns4104s]

What is the best solution to clean wheel bearings? Can you use diesel? Also on inspecting the bearing what do you look for? What do you look for on the race?

Thanks

John

[luvrbus]

John, check for pitting ,flaking and heat marks a little discolor(dull) in the race is normal wear and diesel works for cleaning along with air     good luck

[PP]

I have limited experience with bus bearings LOL, but on smaller vehicles it's almost always pitting that stands out. According to my recent research thanks to some great links provided by others here, the main cause of bearing failure is dirt in the oil. The dirt is literally pressed out of the oil when it gets between the bearing and race causing a lubrication failure. This is taken from research done on bearings by major bearing suppliers, so don't scream at me if others disagree.
Good luck,
Will

[JackConrad]

I was told many years ago, that when using air after cleaning the bearing DO NOT aim the air to spin the bearing at a high rate of speed. There is no lubricant on the bearing and at the very high speed that is possible, the bearing may self destruct, sending shrapnel everywhere.  I have never seen this happen, just what I was told by an old mechanic.  Jack

[JohnEd]

Distinct lines running around the circumference due to to over tightened bearings.

I would be more concerned that you "pack" the bearings properly before reinstalling them. The grease seals are cheap and I don't think I would tear a wheel down without replacing that "consumable" item and don't forget to apply liberal amts of grease to it (the seal) before putting the wheel back on.

I, for the first time in my life, learned the "correct" procedure for setting the preload...tightening a bearing. Seems it is a universal procedure for taper bearings and corrects a "mistake" I had been making for 48 or more years. Apparently the tapers NEED a grease clearance of 1 to 5 thousandths. My bad info, from my teenage years, was that you tighten them up till they are just "snug" after over tightening them to squeeze out the grease to get a "good" feel. You need, and I have, a dial indicator to measure the hub movement to set that clearance. Must not be scientific critical in cars cause the ones I set were definitely over tight but never failed. No doubt, the proper setting for bus/truck stuff is more critical. Get it right!  I had a rear bearing fail after a shop worked on my rear axel and that was a mess.  Don't go there.

John

[gus]

One important thing is to determine whether or not the hub cavity is supposed to be full of grease or just lined.

Most people just fill the cavity full thinking that is the best thing. Sounds logical, but it isn't.

The PO filled my 4104 hub, it is supposed to be only lined. The result is that I had grease oozing out and streaking the front wheels for the next 20K miles.

[Dreamscape]

Hi John, Diesel is one of the best cleaners on metal. It not only lubricates but gets rid of crud. Be careful blowing out bearings, you mights blow some crud in there and not see it. Soak them good for a couple of hours if you have the time. Besides, you should like the way it smells anyway!

~Paul~

[luvrbus]

Paul, every manual I have tells you to blow the bearing dry before pre lube. are you full time now in your bus yet    good luck

[belfert]

I know a bearing is definitely bad if it shows pitting.  The wheel bearings on my bus were badly pitted.  The bus garage showed me one of mine and said I was lucky not to lose a tag wheel on my trip home.  I wasn't going to touch the tag axle, but the garage said I should do it since the fronts and drives were so bad.

[Dreamscape]

Paul, every manual I have tells you to blow the bearing dry before pre lube. are you full time now in your bus yet    good luck

Clifford, I agree, I'm just saying be careful, had a problem on another use and the result was not good, just check it out for freedom before you lube. Yes, we are fulltiming now. That's another story on another thread!

~Paul~