Revisiting OIl bath vs packed grease bearing discussion.

[d2reid]

I am bringing this up because a fellow I respect deeply who has decades of heavy equipment and heavy trailer experience was helping me lube my bearings getting ready for our 5000 miles fall tour. He commited that I should just fill the oil bath bearing/hub with oil and quit fooling around with trying to get grease distributed properly.

Fill the little cuppy thing with oil and you are done? What about all the grease gun pumping, grease spilling out of unusual places, grease on the tires, grease in the grass, trying to get grease off your hands and out of your clothes? There has to be a catch....

So I searched and found that the main problem with the oil bath is leaking seals. And there is a wide variation of opinion on that subject. But when it works, it works well. When it doesn't you have almost instant bearing failure.

So, is there any new information on the subject? Or pretty much the same pros vs cons as 3-4 years ago?

And just because I like to get my engineer friends riled up a bit I am going to ask a question. Just remember, our teachers told us there was no such thing as a stupid question and just because the answer seems obvious you have to be kind to the person because if they already knew the answer they wouldn't ask the quistion; What would happen if I put 90W in the oil bath hub along with Red Tacky axle grease?

[Country Campers]

A: I have not seen or heard any new systems for oil bath hubs on travel trailer axels, as far as direct replacement from stock. I do believe that there are axles available with oil bath hubs.

B: If you add oil to your greased bearings I would guess that the oil will break the grease down and you might have a mess on your hands, again. The general seals used with greased bearings are usually not made to hold oil back from exiting the bearings. The type of oil seal would be a double lip 2 piece seal where the outer seal rotates with the hub and the inner seal stays attached to the spindle. These can be added to a standard spindle but I do not think the spindles are of the needed quality to accept these precision seals.

Brian

[Jlawles2]

OK, let me break this down to what I learned before doing my axles just recently.

Grease seals are just oil seals. MOSST people run the 2 piece seal instead of a single or double lip seal as the 2 piece have a rubber over mold on the inner and outer surfaces to keep the liquid contained.

Oil works wonders on keeping the bearings lubricated and everything happy if used frequently and allowed to get warm to drive out moisture. Trailers that sit are prone to axle shaft and bearing oxidation (rust) due to lack of coating as the oil drains off the surfaces. Grease gets on everything inside the hub and sticks.

Grease is much more forgiving when it comes to imperfections in the sealing surface, to a degree.

Many years ago I had an equipment dealer tell me that they put grease in their rotary shredder gear boxes to help keep the bearings and gears happy when the seals failed, I suspect it was more the grease would defend against grass wrapping better than just a 90W-140 open gear lubricant. Oil and grease can be used in the same system, but be aware of compatibility issues as they can lead to anything from thickness of water to concrete.

[Skilletface]

d2reid, Thanks for bringing this up as I have often given this some thought. I spent most of my life around the wet bearing application and wondering why the 10K axle and under market does not embrace the oil bath concept. Some of the aforementioned issues make sense to me. I’m guessing the average person that own trailers of light duty service and infrequent usage the wet bath bearing would have unforeseeable effects. Parts for the grazeable bearings are readily available in a lot of places and for me that is why I did not pursue the modification after researching. Perhaps one of our neighbours will better enlighten us.

[Jlawles2]

I did use the 2 piece seal on my greased bearing application only because I do not like the idea of the sealing surface and the lip running. If it's not greased before you install the bearing, there is a likely hood that you will end up with corrosion on the shaft and leaking seals. I did grease the shaft, but the rubber liner on the outer and inner surfaces make them a bit easier to install and less likely to leak.