How much can you cook a trailer wheel bearing...

[BogMonster]

Dug the boat out last weekend after six months in the garage, been too busy building an extension over the winter to use it. I thought I'd better try it in a tank before I trailered it in to the slip, needn't have worried as the Etec fired on the second turn of the engine.

One wheel brake was stuck on in the garage, which has happened a lot when it's parked. A few whacks with a hammer unsticks it. However ... when I towed it in to launch (about 5 miles, speeds 20-35mph) I found the hub was very hot when I got to the other end, too hot to touch but didn't actually burn me and no smoke, just a "hot brake" smell. After a bit of investigation I found that the cable was sticking after I'd had the handbrake on, and having bashed the end of the cable back in with a rock at the slip before I recovered the boat, I drove home with no problems and no heat.

It has the original (now 3 year old) sealed waterproof wheel bearings on an ALKO axle (SBS trailer), is a relatively modest overheat like this likely to have damaged the bearing seals? I presume they probably get pretty hot anyway on a long motorway type run elsewhere in the world, so I'm not sure whether I should change it as a precaution (I have neither the time nor inclination to at the moment) or risk using it. No obvious play in the bearing, but I guess it is possible the seals have been damaged by the heat and might have let water in (I let it all cool for about 10-15 min before launching).

Views please? The Etec is due its 3 year service about now, so I've got to set aside some time for boat maintenance but am hoping to leave it all till January when I have a few weeks leave, at which point I will probably do both bearings as well, but I'm hoping I can get away with using it a few times before then. No fast road use - the run to the slip is about 5 miles at the above speeds - and I can jack it up and check it between uses. The old heavy duty adjustable bearings on my old boat trailer would last for quite a while at low speeds even once they got rumbly, but I really don't know how quickly sealed bearings will disintegrate if they get water inside.

[Erin]

Chances are you'll be fine. However, my trailer (which is probably near identical to yours) only gets dunked twice a year and does 3miles each way at 30mph. After the second year, my seals had failed on their own accord and let water in. The inside was a rusty mess. I'm sure I put some photos up on here as getting the bearing savers removed was a bit of a struggle.

[beamishken]

I'd guess that you will have water ingress into the bearings but the distance your doing I'd just keep an eye on them & change when you get the chance the damage is done when it stands for a while but you can tell with a quick jack up & spin if there noisy

if theres no noise & no play I'd keep using it

[Pikey Dave]

I think you'll be ok. I have exactly the same setup, SBS, Al-Ko sealed bearings, sticking brakes The heat from the brakes will have concentrated around the outside of the drum, to get to the bearing seals, the heat has to conduct to the centre of the hub & through the outer bearing race. I doubt it will have got hot enough in 5 miles to do any damage. The bearings are a doddle to change BTW, as long as you have access to a press, which I'm sure you have They cost around £30 quid a set here on the mainland, that's an axle set btw.

[Trimix]

No bearing seal is 100% water proof. The seal covers two moving bits, so it cant be a perfect seal otherwise the bearing would not move.

If you heat it up you will melt the grease in it, that may get hot enough to leak out.

Id be less concerned about the seal, which is a rubber lip, and more concerned about the lack of grease in the bearing.

Get some new ones, they are cheap and when you feel play, replace them. Or carefully lift the seal and regrease them if you can.

[paintman]

If in doubt replace. Better safe than sorry.

When leaving trailers long term best practice is to leave the brakes off. I see a lot of caravans where the brakes have been left on & the shoes have stuck to the drums or the cables have seized - the worst was a twin axle, the owner had noticed it was a bit harder to tow than normal but carried on regardless . The heat generated trashed the the shoes and the bearings. The drums were replaced due to concerns about the heat they had been exposed to.

[willk]

Originally Posted by Pikey Dave

They cost around £30 quid a set here on the mainland

You moved to France, Pikey?

[willk]

Bog Monster - I used the same set of Alkos for three seasons. They never got warm, not even after towing for over 100 miles at around 50mph. No idea about your current situation - just info.

[Nick Hearne]

Never leave a trailer with the hand brake on!
I reckon they will be fine, this is what sealed for life bearing looked like after 5 years of dunking!

[Pikey Dave]

Originally Posted by willk

You moved to France, Pikey?

That's gone straight over mon tete

[willk]

Originally Posted by Pikey Dave

That's gone straight over mon tete

Sorry, I was just enjoying the "mainland" thing. We get a little exercised over here when we hear it in reference to the larger island to our east :-p

[Pikey Dave]

Originally Posted by willk

Sorry, I was just enjoying the "mainland" thing. We get a little exercised over here when we hear it in reference to the larger island to our east :-p

Ahh! Well, knock that chip off your shoulder young sir, you see slights at every turn I was using "Mainland" in the Falklands-British Isles context. If I'd said UK, that would have implied that the Falklands aren't part of the UK, which they very much are & I hope remain so. If I'd said England, I'd have had the Sweatys & Sheep worriers on my case, so here's me thinking that "Mainland" was a pretty safe bet & up pop the Spuddies, I can't win This Polytickley correct business is a bloody minefield

[Trailer Guy]

To answer the thread question: quite a lot!

I had to do an axle change recently, as the bearings had got so hot they'd generated enough heat to adhere the castellated nut to the stub axle. Haven't seen anything like it in twenty years I've been servicing trailers.

When I went to undo the castellated nut (with just a 12" adjustable) the end of the stub axle came clean off in the castellated nut. You can see what's left of the outer bearing case and the threaded portion of the stub axle still in the castellated nut...

[willk]

Originally Posted by Pikey Dave

Ahh! Well, knock that chip off your shoulder young sir, you see slights at every turn I was using "Mainland" in the Falklands-British Isles context. If I'd said UK, that would have implied that the Falklands aren't part of the UK, which they very much are & I hope remain so. If I'd said England, I'd have had the Sweatys & Sheep worriers on my case, so here's me thinking that "Mainland" was a pretty safe bet & up pop the Spuddies, I can't win This Polytickley correct business is a bloody minefield

No chip here - I just enjoy seeing the mind at work in the word

You Yorkies appear to be able to stretch the term "mainland" as far as you can stretch a pound. You could have said UK as the Falklands are a British Overseas Territory. "Mainland" would suggest the nearest major landmass.....

[m chappelow]

Ok not exactly an overheated wheel bearing but once saw a hard boat being towed down the A1 in North yorks that came past me about 65 mph with the jocky wheel on fire : 0

[Bigmuz7]

Originally Posted by Trailer Guy

To answer the thread question: quite a lot!

I had to do an axle change recently, as the bearings had got so hot they'd generated enough heat to adhere the castellated nut to the stub axle. Haven't seen anything like it in twenty years I've been servicing trailers.

When I went to undo the castellated nut (with just a 12" adjustable) the end of the stub axle came clean off in the castellated nut. You can see what's left of the outer bearing case and the threaded portion of the stub axle still in the castellated nut...

Its a wonder there wasnt a fire there .. doesent look right ? Never seen that meself and I run 8 plant trailers commercially as well as me boat.How would just the outer end get that hot, and the rest of the backplate and shoes not get fried ? ..weird

[Pikey Dave]

Originally Posted by willk

No chip here - I just enjoy seeing the mind at work in the word

You Yorkies appear to be able to stretch the term "mainland" as far as you can stretch a pound. You could have said UK as the Falklands are a British Overseas Territory. "Mainland" would suggest the nearest major landmass.....

Get away wid yiz, we all know that anything outside Yorkshire is "Foreign"

[Trailer Guy]

Originally Posted by Bigmuz7

Its a wonder there wasnt a fire there .. doesent look right ? Never seen that meself and I run 8 plant trailers commercially as well as me boat.How would just the outer end get that hot, and the rest of the backplate and shoes not get fried ? ..weird

Both bearings had collapsed, the shoes were brand new, hence they don't look too bad I guess, but I agree, they were lucky it didn't catch light.

[paintman]

I will admit to once overtightening a taper roller bearing on the front wheel of the Scimitar I owned at the time. The resultant heat destroyed the bearing cage & welded the inner rear race to the stub axle.
What fun that was to get off

[Bigmuz7]

Originally Posted by Trailer Guy

Both bearings had collapsed, the shoes were brand new, hence they don't look too bad I guess, but I agree, they were lucky it didn't catch light.

So ... bearing collapse .. long motorway run .. no breaking .. probably a big SUV (as they didnt hear the rumble.. presumably ? ) and heavy boat on a single axle trailer? or double TG ? I see the bearing on the mud guard of the left wheel

The heat is evident from the grease loss from the inner race.. over the shoes.

With that heat on the outers.. the hub cap would have melted if it was plastic and thrown grease all over the rim hastening the demise

the inner stub is still wet with grease but the outer is dry and indeed rusted, so the heat was intense indeed

Over torque quite possible, the washer on the other side of the castellated nut shows signs of rotation, which provides more friction, once the grease has gone and generates heat, if the bearing got dry and bobs your aunti .. can you elaborate on the conditions before the failure TG ?