mark and kerry wrote:

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Hi does anybody run oil in their bearing hubs

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 Just curious as to why would you or want to

Ian( ex, very ex mechanic)

mark and kerry wrote:

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Hi does anybody run oil in their bearing hubs

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 Many boat trailer axle hubs now run oil filled hubs.

The hubs of semi trailers have been using oil filled hubs for their trailer axles.

As opposed to the oil filled hubs that are incorporated in fully floating vehicle axles, the trailer hubs in most cases have a sight glass which provides an easily accessible and convenient way to visually check the hubs. If they have oil in the sight glass and the bearing is not hot then the bearing is OK. It is also very visible if the oil is leaking out.

My thoughts are if asked the question of would I use them on a caravan.

They are handy but unless my van came with them I would not bother to change to that system.

Annual inspection and repacking of grease lubricated hubs is all that is really necessary unless operating under extreme conditions or immersing the hubs in water when crossing creeks etc.

One good modification that can be done is the fitting of the reverse type hub seal that greased boat trailer hubs typically use, into your caravan hub.

These type of seals prevent pressure build up in greased hubs and subsequently prevent a pressure differential in the hub if immersed in water due to the differing temperature of the air in the hub as opposed to the sudden cold environment when the hub is immersed.

With a standard hub seal in a greased hub the pressure difference will permit water ingress into the hub. The water will just get sucked through the seal surface on the axle. The water will destroy what was once a good serviceable bearing set.

Talk to any mechanic involved with trailer servicing for any more info with the fores and againsts.

I fit marine hub seals to my van and trailer every time I service and repack the grease in the bearing and hub.

I should probably add that the *bearing buddies* that most greased hub boat trailers have actually maintains some pressure within the hub particularly if they are running a standard automotive hub seal. If they have a marine seal which is basically a standard seal with their sealing lip facing the opposite way to the standard seal, then over zealous greasing with a grease gun will cause grease to come out of the seal area.

If any van owner is unfamiliar with how all this works in theory then it would be best to discuss your requirements by explaining your intended operating conditions with a qualified mechanic.

 

-- Edited by Rob Driver on Friday 14th of January 2022 02:03:23 PM

Wanda wrote:

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Peter_n_Margaret wrote:

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Every full floating rear axle is lubricated by oil from the differential. They do not get water in them like the front wheel bearings can.
Grease is simply oil in a carrier so it stays where it is needed. It is possible to run trailer bearings in oil with a feed resavoir feeding through drilled holes in the axle. Has great advantages in keeping water out.
Cheers,
Peter

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 Yes I realise all that, but on a caravan?

Ian

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 Good idea on any wheel bearing set, including caravans.

Cheers,

Peter

I remember when semi trailers went from greased hubs to oil filled hubs.

The oil filled hubs were a lot easier to check than the old greasy ones.
Check the oil level at each tyre check. Have a feel for excess temperature and you were on your way.
If a seal failed in an oil hub there was quite a visible oil leak from the backing plate area.
A seal could pop out or fail in a greasy hub and there would be no evidence until the bearing got full of dust or water or both and then failed.

I am a bit like Rob above, I have not considered oiler hubs on my van. I stay mainly on the bitumen and really repacking the bearing checking and adjusting the brakes and replacing the hub seals just an annual maintenance task.
If I had a genuine off road van and was using it genuinely off road then I would seriously consider oiler hubs.

One thing I would warn of anyone using oiler hubs or bearing buddies is that in the off road situation the hub fitting that does tend to extend outward of the original hub can easily be knocked off the hub by a rock or a stick under certain conditions.
I saw a bloke that had this happen and to fix it he had cut the end out of the pretty hub cap that Rob mentioned above. This gave himself some protection for the oiler and he could still see the oil level.
Most of those pretty hub caps fit in behind the wheel against the hub flange so cutting the end out doesnt affect them apart from looks.
It didnt pass the pretty van dealer test but it sure protected the hub fitting.

A couple of informative posts from Rob above, thanks for the description.