Page 1 of 2

Converting to oil bath hubs

Posted: Wed Sep 13, 2006 7:41 pm
by DLT
Anyone ever have a look at this?

What do you think?

Seems cheap and easy to me... Also alot easier to check... Just walk around and visibly see the oil level...

Posted: Wed Sep 13, 2006 8:24 pm
by Paul S
The folks at ufp and waymire recommended the parts that were on the trailer as they are well made. The stock parts on the M trailer sure seem well made. The rear/inner seal is very tough, the bearing protector is very well made and reliable.

I have seen the oil bath before. No experience with it.

It is not all that difficult to press on the edge of supplied bearing protector to see if there is grease in it. I don't think I added any since we got the trailer...the grease (see the pics in the other thread) looked brand new. Not a drop of water or any contamination. I think I will stick with stock.

But there are good alternatatives out there. I just have no personal experience with the oil bath to comment good or bad.

Paul

Posted: Thu Sep 14, 2006 6:20 am
by MSN-Travelers
I have no experience with oil bath bearings on boat trailers but they are proven technology in the commercial trucking industry. Most semi's that you see on the road will have oil bath bearings. I have them on the semi-trailer in our fleet and they are trouble free.

what about leaking oil

Posted: Thu Sep 14, 2006 7:09 am
by Robert
Leaking grease is an asthetic problem mostly, since wheel bearing grease is made to stick to the bearings. What about an oil leak? How long would the bearings last if the oil leaked out? That is how long you have to notice the leak.

Posted: Thu Sep 14, 2006 8:26 am
by Catigale
There was an old thread on this some time back, and Scott is in the trucking business, so can probably comment on his experience here.

Of course, the design needs of bearings for trucks, and bearings that will be immersed in water from time to time may differ....

:D

Re: what about leaking oil

Posted: Thu Sep 14, 2006 8:27 am
by DLT
Robert wrote:Leaking grease is an asthetic problem mostly, since wheel bearing grease is made to stick to the bearings. What about an oil leak? How long would the bearings last if the oil leaked out? That is how long you have to notice the leak.
True. But, you can say the same for grease, right? Granted, the oil would more quickly exploit any leak...

If the seals hold, then is there a problem? It seems easier/cleaner to maintain...

Here's my issue. I've had to put more grease into one of my bearings, than I think I ought to. I'm worried about it. Therefore, I check it frequently, which is a good thing. But, checking involves removing the dust cover/bra, which is dirty/greasy. Never mind the mess when I have to add grease. (Yeah, I recongize that many of you can probably manage this whole process cleaner then me, but...) So, even if all is well, I have walk away with a greasy, dirty hand...

With this oil bath setup, I could check the oil level with my M1 eyeball...

Posted: Thu Sep 14, 2006 10:59 am
by Hamin' X
Maybe the manufacturer of the units that you have pictured have a different design than our truck oiler bearings, but ours are designed to breathe. That is so that the heat developed during use does not blow out the inner seal, or the filler cap. At any rate, the hubs run at ambient air pressure. I would think that immersing warm hubs in water would tend to "suck" in water. The bearing buddy type of greaser keeps a positive pressure in the hub to prevent this. Twere me, I'd stick with the pressure type. YMMV

Rich

Posted: Thu Sep 14, 2006 1:35 pm
by Bobby T.-26X #4767
i agree with Hamin'X.
you cannot convince me that oil hubs are meant for marine application.
plus, i don't trust the "seals" on the inside that float around the axle. i gotta believe that they will be prone to leaks as much (or more) as the grease seals.
the difference being that the oil will escape easily via gravity while grease is condensed enough to stay (for the most part) inside the bearings to do it's job.

Posted: Thu Sep 14, 2006 3:30 pm
by DLT
You guys are probably right...

Although, transmission and engine seals seem to work fine... So, I wasn't too concerned about oil versus grease. Of course, they are not commonly submerged, which seems to be the issue...

Posted: Thu Sep 14, 2006 3:39 pm
by Scott
All axles on all large trucks are oil bath.

Next time you go by a truck look at the front axle and you will see a plastic sight cover.
Leaking grease is an asthetic problem mostly, since wheel bearing grease is made to stick to the bearings. What about an oil leak? How long would the bearings last if the oil leaked out? That is how long you have to notice the leak.
Not so...

The only time they are a failure point is if the seals dry out or the mating surface pits. (The smooth surface that the seal rides on.) This shouldnt be any more frequent of a problem than with greased hubs as the same conditions will cause your hub to fill with water and your bearing will fail. Greased or oil bath.

In some instances I think I would rather have oil bath because it is so easy to spot a leak. Just look for oil on the inside sidewall of your tire. This is not as easy to determine with greased hubs.

Maintainance is way easier too. Just squirt in more oil if it gets low.

Lastly, an oil bathed bearing rides cooler than a greased one and subsequently will last longer.

Posted: Thu Sep 14, 2006 3:46 pm
by DLT
Ok, Scott, this is sort of what I was thinking.

But, what about submersion, as mentioned above? If the hub is warm when it hits the drink, will it try to suck water in past the seal?

Water is heavier than oil, so any water in the hub will be washed over the bearings, as they wheel rolls. Thus, you'll just be "rinsing" your bearings, not lubricating them, if water gets into the hub...

Posted: Thu Sep 14, 2006 4:24 pm
by Frank C
Tiedown Engineering makes a wet hub called Turbo Lube. I put them on my 26X trailer temporarily while upgrading to the 15" tires, but before installing the disc brakes. They worked fine, but I avoided dunking them while hot. Tiedown disavows any warranty on boat trailers, so they've obviously determined that there are some issues. FWIW, Tiedown's inner seal is far, far inferior to the Kodiak seals.

Contrast this with Kodiak and UFP. They both include a wet hub kit with their disc brakes. Neither of them issues warnings about boat trailers. UFP also sells torsion axles, specifically recommended for use on marine trailers.

I'm using Kodiak's wet hubs with my Kodiak discs, but my installer was unfamiliar and packed the bearings with that heavy, red-colored, marine grease! Not sure what I'll do about it, but for short towing I'm not concerned as is. Overall I like Scott's logic on this issue - easy to spot a leak, cooler running, and I like the quick visual verification of the lube level. I'd also try to avoid a warm dunk, but considering the need to rig the Mac before dunking ... no big deal.

Posted: Thu Sep 14, 2006 5:20 pm
by Scott
Well, in my opinion if your hub is hot enough to "suck water" when cooled wouldnt that be an indication of a problem to begin with??

Also if your "oil bath" hubs will suck water, wouldnt a warmer "Greased" hub be worse.

Unless you are running a high dollar waterproof grease you will completly break down the grease the first time you tow it with water in it. Even with waterproof grease the most recent contact surface in the bearing will be clean enough to rust. Then the next time you tow it the rust will cause the bearing to fail.

I think it is 6 of 1 1/2 doz of the other as far as "sucking water" goes.

Posted: Thu Sep 14, 2006 6:58 pm
by Chip Hindes
Well, in my opinion if your hub is hot enough to "suck water" when cooled wouldnt that be an indication of a problem to begin with?? :o
No. Any hub will run warmer than ambient, and it only takes a few degrees different than ambient to cause the hubs to want to "breathe". The seals in the back side of the hubs are like one way valves. They are designed to keep grease in under internal preassure. However, if the internal pressure drops below ambient, they open right up. If in air, no big deal. If under water (which is what causes them to cool and drop pressure quickly) very big deal.
Also if your "oil bath" hubs will suck water, wouldn't a warmer "Greased" hub be worse.
Not worse, the same. But the greased hubs with Bearing Buddies are designed to operate under positive pressure in the hubs specifically to prevent this. Oil bath hubs are not.
Unless you are running a high dollar waterproof grease you will completly break down the grease the first time you tow it with water in it.
Marine wheel beariing grease is not really waterproof but it's specifically designed to continue to lubricate with some amount water in it. You may term it "high dollar" but it is not that much more expensive than standard grease. Certainly in the relativley small quantity needed for two or four boat trailer hubs it's worth the difference.

However, if your Bearing Buddies are working as they should, water will not get into the grease.

Becuase of its higher viscosity, grease is easier to contain with a seal than oil. Plus one for grease. Of couse, it runs hotter than oil. Minus one for grease. However, if the Bearing Buddies are working....
I think it is 6 of 1 1/2 doz of the other as far as "sucking water" goes.
Disagree pretty strongly.

Posted: Thu Sep 14, 2006 7:59 pm
by DLT
Thanks Chip,

I was waiting to hear from you...

Ok, I'm going to stick with my greased hubs...