Joint Grease in the Wheel Bearing Hub

The grease hub caps are also vented..
Make sure no excess grease is covering the vent.
Otherwise it will build pressure and blow the seal.

 

Correct me if I'm wrong, but I do not think you can drain all the oil from the hub by just draining and refilling in five minutes. I doubt that by removing the fill plug or removing the complete cap will drain the oil out of the hub cavity between the inner/outer bearings. The hubs have a recess in this area as a reservoir and it is lower than the bottom of the outside cap.

 

You are correct. Removing the cap does not drain all of the oil and only about half or less usually. The only exception would be if the hub were equipped with an allen (o-ring) plug in the center outside diameter of the hub, which would allow you to drain the hub cavity. I don't recall ever seen these before on a trailer hub, but that doesn't mean they don't exist. They are the cats ### on drive axle hubs for prefilling to prevent dry run. When doing an axle lube change on your tractor it only take a bit longer to change the hub oils too. Jack it up and put the plugs down to drain. This is best to do when the axle warm still. Rotate them up to the top and refill with new oil. The amount is not critical- just fill with more than you drain out and fill the diff last. This is a great idea to extend wheel bearing life as the lube does not recirculate back through the diff.

 

I am curious about how often you change 1/4th of the oil in your hubs and why you think it helps? If you have a problem you will have heat in the hub - grease or oil. If you don't you won't. Doesn't have anything to do with lazy and as others have noted, the industry is going back to grease in some applications.

 

I will admit I used the wrong choice word there. No hub assembly that originally was spec'd for lube should be packed with grease just because a seal keeps leaking. Get a better wheel seal or learn how to correctly install them so they dont leak.

The type of hub depends on the amount of oil you get out. On today's newer tractors all wheel ends are able to be drained completely. Older trailers you are correct you only get out what dribbles out with the cap off. If its nasty might as well take it apart for a thorough inspection.