Wheel Bearing Oil Bath

Baz421 · Guru

Wheel Bearing Oil Bath

Peter_n_Margaret · Guru

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Dougwe · Chief one feather

Wheel Bearing Oil Bath

jimricho · Guru

I think that system is intended to address a problem that is specific to boat trailers. That is that wheel bearings warm up while driving and then are subject to sudden cooling when dunked in the water (often salt water) when launching the boat. This causes the bearings to suck in water and the combined effect of salt water, and consequent corrosion turns the grease into grinding paste.

Many boat trailers are fitted with "Bearing Buddies" that enable the grease to be maintained under positive pressure and easily replenished with grease. I had these fitted to my boat trailer when I owned one. The oil bath system is another attempt to address this issue. How successful it is I have no idea.

I don't see this as being an issue with caravans and camper trailers so I don't see the point in fitting them.

hako · Guru

Doug, when bearings get hot (as they will especially when braking), oil will then leak past the oil seal and contaminate the brake shoes. Tried and proven method of repacking bearings is still the best IMHO.
Regards

Baz421 · Guru

Same problem with grease and oil filled hubs - YOU NEED TO KEEP THE WATER OUT. Seals need to achieve this no matter what is inside hub, oil or grease.

You can argue positives and negatives for both BUT it's the seal that does the job, not whats in the hub.

For serious applicatons you can get double lipped seals (ie one lip keeps grease/oil IN and the other keeps water/dirt OUT), but boat trailers in Oz tend to use single seals only and the machined surface on the axle may not be wide enough for double lipped seals.

Hope this helps explain it a bit.

Cheers Baz

Peter_n_Margaret · Guru

Every full floating rear axle wheel bearing runs in oil from the differential.
No problem with lubrication.

The purpose of the "Bearing Buddy" system is to maintain a positive pressure in the bearing area such that if there is a slight leak at the seal, it leaks grease out instead of water in.

Oil systems can do the same thing because there is typically a bottle of oil above the axle that replaces any oil that leaks out past the seal.

Mercedes Unimogs actually pressurise the whole drive train (including diffs, wheel bearings, gearboxes and universal joints) with air at 0.5psi to keep water out, but they tend to cost a bit too much for the average punter. :)

Cheers,
Peter

blaze · Guru

hako wrote:
Doug, when bearings get hot (as they will especially when braking), oil will then leak past the oil seal and contaminate the brake shoes. Tried and proven method of repacking bearings is still the best IMHO.
Regards

the statement that they will leak ecause of heat is misleading, there are many places where oil is sealed with the same type of lip seal as a wheel bearing with heat far in excess of what a braked wheel will produce. I do however agree with you the the best and proven method is qualiity grease is the way to go for wheel bearings. How many times do you see a dust cap that has been knocked off a wheel and its still turning, now if that was oil it would have leaked out and led to a failure

cheers

blaze

snapper49 · Senior Member

The oil system really is a much better way of lubricating the bearings
The bearing rollers etc are continually immersed in oil
When one takes a greased bearing out you will see nice clean shiny areas where the grease is restricted from penetrating
With the oil system one can view the level of oil at a glance as the caps are clear
Have had experience with both and the oil system is much better and no leaks

jimricho · Guru

I've been told to repack and if necessary replace the van's wheel bearings every two years or 10,000kms. My Pajero is almost ten years old, 135,000kms, regularly dealer serviced, and still has its original wheel bearings. The bearings are not lubricated from the diffs as the Paj is independent suspension all round. What I can't work out is why I'm supposed to replace the van's bearings so frequently but not the car's???????

This a genuine question and not a challenge to anyone's previous posts on this topic.

turbopete · Senior Member

Hi Jim there is no good reason to change van bearings at 10,000,,,,is an urban myth to frighten us old farts into parting with our hard earned,,im allowed to say that i,m 72

Dougwe · Chief one feather

Thanks everyone for your comments so far. I will wait and see if any more comments make there way here before a final decision.

jimricho · Guru

turbopete wrote:
Hi Jim there is no good reason to change van bearings at 10,000,,,,is an urban myth to frighten us old farts into parting with our hard earned,,im allowed to say that i,m 72

Just as I thought!

jimricho · Guru

Dougwe wrote:
Thanks everyone for your comments so far. I will wait and see if any more comments make there way here before a final decision.

I can't help but think you'd be spending your hard-earned on a non-existent problem. Save your dough for more important high priority expenses. (beer, wine etc)

blaze · Guru

jimricho wrote:
I've been told to repack and if necessary replace the van's wheel bearings every two years or 10,000kms. My Pajero is almost ten years old, 135,000kms, regularly dealer serviced, and still has its original wheel bearings. The bearings are not lubricated from the diffs as the Paj is independent suspension all round. What I can't work out is why I'm supposed to replace the van's bearings so frequently but not the car's???????

This a genuine question and not a challenge to anyone's previous posts on this topic.

the bearings in the pajero will be about 3 inches in diameter the ones in the van about half that. the van sits for longer with no rotation and load, not a good combanation. In saying all that your van bearings should do 10 years with proper servicing but for the price and ease of changinging , every couple of years is proably a good service time (well before any failure)

cheers

blaze

hako · Guru

jimricho wrote:

I can't help but think you'd be spending your hard-earned on a non-existent problem. Save your dough for more important high priority expenses. (beer, wine etc)

That is a very sensible post.

wasn_me · Guru

If you have to replace van wheel bearings use quality brand name bearings, timken etc. Most of the under $20 bearing kits from "cheapy stores" would be unknown quality, they usually don't even have a maker name on them. Also use a good quality high temperature, water resistant grease. There is usually grease on the shelf specifically designed for disc brake hubs, that will be suitable for high temp.

On a single axle van you often have two wheels sharing the weight that four would be sharing on a car (another reason for more regular maintenance than the car). It's an area you can not try to save money. Wheel bearings or springs on the van are the two most common things to strand a traveller. It pays to carry a spare bearing set & a container of grease. Murphys Law, if you've got spares you won't have a breakdown.

I agree with snapper49, oil is a far better lubricant than grease. I would be worried if oil did get into the brakes. I'd like to see it sucessfully used & proven before I went that way.

Cheers Pete

-- Edited by wasn_me on Sunday 20th of January 2013 08:59:49 AM

-- Edited by wasn_me on Sunday 20th of January 2013 09:03:24 AM

Dougwe · Chief one feather

I just stocked up on some of that amba fluid yesterday, it was on a good special, so no money left for the Avan. Mmmm, maybe the Avan bearing could sit in a beer bath? biggrin

jimricho · Guru

Dougwe wrote:
Mmmm, maybe the Avan bearing could sit in a beer bath?

Put through a kidney filter first perhaps???????

jimricho · Guru

blaze wrote:
jimricho wrote:
I've been told to repack and if necessary replace the van's wheel bearings every two years or 10,000kms. My Pajero is almost ten years old, 135,000kms, regularly dealer serviced, and still has its original wheel bearings. The bearings are not lubricated from the diffs as the Paj is independent suspension all round. What I can't work out is why I'm supposed to replace the van's bearings so frequently but not the car's???????

This a genuine question and not a challenge to anyone's previous posts on this topic.
the bearings in the pajero will be about 3 inches in diameter the ones in the van about half that. the van sits for longer with no rotation and load, not a good combanation. In saying all that your van bearings should do 10 years with proper servicing but for the price and ease of changinging , every couple of years is proably a good service time (well before any failure)
cheers
blaze

My erstwhile van maintenance wallah has been replacing the bearings each year, not just checking them. I do several thousand kilometres each year. The van uses Ford bearings and has an ATM of 1350kg.

I say "erstwhile" because last service he found a broken brake shoe and claimed he couldn't get a suitable replacement so he replaced the whole backing plate assembly, both sides, magnets and all, and charged me an arm and a leg for doing so. He no longer has my business.

Jim

blaze · Guru

wasn_me wrote:
If you have to replace van wheel bearings use quality brand name bearings, timken etc. Most of the under $20 bearing kits from "cheapy stores" would be unknown quality, they usually don't even have a maker name on them. Also use a good quality high temperature, water resistant grease. There is usually grease on the shelf specifically designed for disc brake hubs, that will be suitable for high temp.
On a single axle van you often have two wheels sharing the weight that four would be sharing on a car (another reason for more regular maintenance than the car). It's an area you can not try to save money. Wheel bearings or springs on the van are the two most common things to strand a traveller. It pays to carry a spare bearing set & a container of grease. Murphys Law, if you've got spares you won't have a breakdown.
I agree with snapper49, oil is a far better lubricant than grease. I would be worried if oil did get into the brakes. I'd like to see it sucessfully used & proven before I went that way.
Cheers Pete
Truck trailers have been using the oil bath method on the trailers for at least 25 years and doing millions of kms. I still maintain for the average van owner the KISS method is best, keep the grease
cheers
blaze

-- Edited by wasn_me on Sunday 20th of January 2013 08:59:49 AM

-- Edited by wasn_me on Sunday 20th of January 2013 09:03:24 AM