Oil Bath Hubs

I bought a used boat last fall. Its got an EZ Loader trailer with Reliable oil bath hubs.

I know nothing about oil bath hubs. I have noticed they do run cooler than grease. They also look easier to maintain.

For the guys who have or have had oil bath hubs, are they reliable?

The thought of being 300 miles from home and having the oil leak out of a hub is a bit unnerving.

They are very reliable

Have you ever had a leaky hub?

Would it make sense to carry a spare cap, o ring and oil?

koldfront kraig wrote:

For the guys who have or have had oil bath hubs, are they reliable?

Everybody points to the fact that semi-truck trailers run oil bath hubs as a sign of their reliability, but there’s a problem with that line of thinking. When’s the last time you saw a trucker back his trailer deck-deep in muddy water?

Like everything else, if maintained properly, oil bath hubs are reliable. But IF they fail and lose oil, they will burn up completely in short order.

With traditional grease-filled trailer bearings, there is some margin for error so to speak because the grease is sticking to the bearings and a bad seal won’t let the grease completely out. Also, there is some level of water contamination that grease bearings can withstand and still function. If you catch a bearing running warm, adding some grease will likely at least get you home.

IMO you have to stay on top of maintenance more with oil bath hubs because the seals have to stay nearly perfect in order to keep grit and water out and to keep the vital lubricating oil in. You have to see and recognize the signs of leaking and water contamination before things get bad enough that you could potentially lose a seal while on the road.

So there are pros and cons is the bottom line, especially with the use of oil bath hubs on boat trailers.

Being a grease hub guy that was my thinking as well.

I’d like to hear from people who own or have owned oil hubs.

You just need to watch the seal on the back to make sure it doesn’t start to leak. If it starts leaking make sure to replace the seal right away. When they start to leak unlike grease they leak out faster. After each trip lay on the ground and look at the back to check for signs of oil. If dry good to go until the next trip.

Going on 14 years with oil bath. Very pleased with the almost zero maintenance so far. Have yet to replace a seal or O-ring. Changed the oil once. Doubtful it was needed. How often does one change the oil in a rear axle gear housing? Same difference.

TheFamousGrouse wrote:

Everybody points to the fact that semi-truck trailers run oil bath hubs as a sign of their reliability, but there’s a problem with that line of thinking. When’s the last time you saw a trucker back his trailer deck-deep in muddy water?

I see them submerged every day in the mud on job sites. They can go through alot of abuse. Just like everything, maintenance is key. But to pretend side dumps, dump, trucks and all these trucks don’t see muddy water is fantasy land.

OK, I’ll keep the oil bath hubs but maybe buy a spare hub kit just to be safe.

Thanks guys.

I’ve had a trailer with oil bath hubs for 17 years. One seal started leaking 2 years ago and had all 4 of them replaced. That’s the only maintenance I’ve ever done with them.

Ranger Boat Trailers have been running them for at least 20+ years. Mine have been flawless for the last 17 years.

Not sure if the EZ loader trailer have a window on the hub so you can see the oil level? If the oil turns milky, there is water in the hub.

Easy to change the oil. Remove the tire. Spin the hub until you see an Allen Screw. Remove that screw and turn hub down. Let drain. (Takes a while) Then fill with the recommended oil. Replace screw. Replace tire.

Also note. I know one guy who ran an empty hub for several hundred miles with no damage. So I would assume you can limp home in a pinch.

-J.

This is what they look like.

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The oil color looks good. Level looks a little low. I run mine at about 80% full. This allows for some expansion due to temp changes. You may want to see if there is a specific amount used in an owners manual. 1/2 full may be the correct amount for your hubs?

If the rear seal is leaking, there would be oil coating the inside of the rim.

-J.

1/2 full is the correct level on my Strato trailer.

Like JJ mentioned my 1998 Ranger trailer had them. Carry an extra if you want to. Just look for milky colored oil.

I have the same hubs and it was converted to grease at some point.
FYI – the bearings for oil and grease are the same so converting over is easy and you can use the same parts.

Haven’t touched my oil bath hubs in last two trailers. If you are worried about it buy a spare hub assembly. Not the parts to do it on the road. Swap whole hub.

It says “full to top of logo.”

Ralph Wiggum wrote:

It says “full to top of logo.”

Great catch.

I have a different brand on my 25 year old boat trailer…. Leak a little all the time as the manufacturer says they will when the oil expands. Once a year add a little and every couple drain and add new. So simple. I contemplated changing out but honestly love them. I may swap seals in back eventually…. But have grown to like having them far more than grease.