Shortest wheel bearing life.....

[al40]

Replaced inner and outer bearings (incl shells), oil seals etc and re-packed with lucas xtra heavy duty wheel bearing grease (the blue / green stuff). I then towed the trailer for 100 miles, topped up the bearing savers and launched and recovered 4 times on a camp site, washing the hubs out each time. Did a quick check and one wheel was rumbling! Bearing was badly pitted and worn - under 2 weeks old!

It is possible the oil seal failed I guess but I was shocked at how little it lasted! Thanlfully I had a couple of spare sets so replaced and re-packed. The other side was perfect with no water ingress. The stud part looked fine with no corrosion where the oil seal fits so I don't think that was the problem!

Outer bearings are fine due to bearing savers but looking at design of hub (M&E axle) I do not think it is possible for grease to migrate from outer to inner bearing!)

[Limey Linda]

What method did you use to pack your bearings?

[al40]

large glob of grease in palm of hand and basically push it up through the bearings (wide end down) till it comes out the top of the bearing race (so bearing is fully packed). What I didn't do was completely fill the cavity before pushing the oil seal on (various forums recommended not to do this with scare-mongering of bearings overheating with too much grease), but did put a fair amount of grease in gap between oil seal and bearing.

Both sides done the same and only one side had the problem.

Incidently, when I replaced the bearing and re-packed, I put as much grease in as possible so it was squirting out when pushed the oil seal in. Bearings cool after 100 miles.

[Limey Linda]

Your method is spot on. I can only guess it was a faulty bearing or you unknowingly got some grit in it.

[Bigmuz7]

It doesnt take much in the way of a metal filing to rub a bearing surface and cause it to pick up,.. and then it just starts to self destruct, not common but it does happen, especially if it took force to push those 1st sets in

[Cookee]

Originally Posted by al40

(various forums recommended not to do this with scare-mongering of bearings overheating with too much grease),

Well that's a first! How do they reckon that's going to happen then? Not calling them liars, but interested in the theory!

[9D280]

Changed in it's usual parking place? As Bigmuz says, doesn't take a lot to kill a bearing. Grease sticks to dust & grit like the proverbial bown stuff to a blanket........ I wonder - one badly timed gust of wind threw a small bit of grit in as you packed the bearings? Or did your hand get contaminated? Was it the first or second one you changed that failed?

As for the overheating story, it melts and basically squirts out the seal. On my dinghy Combi (unbraked hubs) I always spent three or 4 trips cleaning grease off the back of my wheels after I changed bearings - when it stops spewing grease, I know the correct quantity is in there! (and it then runs for another 10,000+ miles with no issues) Granted those bearings don't go swimming.

The good thing about this story is it's the perfect example of why you should always carry a spare set of bearings with you........

[jyasaki]

Originally Posted by al40

What I didn't do was completely fill the cavity before pushing the oil seal on (various forums recommended not to do this with scare-mongering of bearings overheating with too much grease),

???

As far as I am aware, the more grease you get in (and conversely, the less air you leave in) the better. Not sure a) what "too much grease" would mean, nor b) how that would cause a bearing to overheat.

Did the grease appear to be milky or creamy? If so, water got in somewhere (usually through the grease seal, though the dust cover/bearing buddy is a possibility as well.) Salt water, even when mixed in with grease, will do a number on the bearings in no time.

If not and the grease appeared normal, I'd suspect some contamination (sand, dirt, metal shavings, etc.) got in with the grease (though I'd also suspect that it had to be a lot of crap to take it out that quickly.)

One thing to be careful about is the use of bearing savers: Pumping grease in is good, but pumping in too much may invert the grease seals on the inside and allow water ingress. You should pump the grease in until the spring loaded flange *almost* hits its stop. Don't go nuts and pump grease in 'til it oozes out somewhere (unless you have spindle-lube type hubs.)


jky

[codprawn]

Does anyone do solid phosphor bronze or olite bearings for trailers? Has anyone tried it? I know they are a lot of work but so ball/taper bearings on a boat trailer!!!

[jwalker]

Originally Posted by Cookee

Well that's a first! How do they reckon that's going to happen then? Not calling them liars, but interested in the theory!

Cookee, my understanding is that a full bearing is working as a grease pump and so the temperature rises. With thick grease it can get worse because the wedge of thick grease in front of the roller may be sufficient to prevent the roller turning and so it skids around the track further increasing heat and it may burn the grease local to the roller.

Having said that, on a boat trailer which is immersed in water, I reckon filling the whole bearing housing is the only option.

[al40]

Many questions :-)

I was miticulous in cleaning the new hub assembly before and after putting the new bearing in (washed with petrol with paint brush and then sprayed with brake cleaner when dry - Iactually did this before and after fitting the new shells). Bearings were sealed until used etc so I am pretty much 100% confident that the bearing assembly was clean.

There were signs of water ingress (something I didn't mention) so the seal had failed to some degree.

I still do not believe that it's possible for grease to get from the outer to inner bearing with the hub assembly on my trailer. The bearing savers are those crappy Autow style ones that don't maintain any pressure (just a glorified fill cap with centre breathing hole) - came fitted to trailer. They were not over pressured (topped up slowly until grease starts to ooze out of the centre breather)

My theory is.....

Flushing the brakes after use and then not driving is a BAD idea... Whilst it does wash water off the brake assembly, it also puts pressure on the oil seal and could potentially inject water into the bearings. If there was any salt water lurking around (which there will be), this could potentially be forced into the bearings. As soon as there is any salt in there, games a bogie! Driving after immersion would warm things up a bit (as well as drying the brakes!) and distribute grease again.

Re over greasing the bearing assembly - I was reccomended not to do this when I spoke to Insespension... In reality, there was still a lot of grease in there but the area between rear of bearing and the oil seal wasn't crammed full. 2nd time I did the bearings it was!

=> Morale of the story - check your bearings often!

Would be interested in opinions of flush ports and impact on bearings!

(edit - For braked trailers I can see the reasoning of not having grease oozing into the brake area as it could potentially impact the braking - this may be the reason insespension voted not to full it 100% full.)

[bedajim]

Originally Posted by codprawn

Does anyone do solid phosphor bronze or olite bearings for trailers? Has anyone tried it? I know they are a lot of work but so ball/taper bearings on a boat trailer!!!

My launch trolley has them & stainless shafts + the same on the road trailer rollers where the trolley rides. Not sure how good they would be for prolonged high speed use

Came back from Cornwall couple of weeks ago and passed 4 trailers on the hard shoulder wheels off etc one with brakes smoking badly

[Bigmuz7]

Originally Posted by al40

=> Morale of the story - check your bearings often!

You will never beat the salt/corrosion/rust from causing havoc with bearings .. breaks etc .. no mater what methods you use, including direct flushing every time then driving, or using bearing savers. Yes you might slow it down a bit, but never prevent it, so in reply to your above point, my moral is depending on your annual mileage (and *touches wood* this one hasn't let me down yet)

Have a time frame for replacement of bearings, brake shoes, cables, BEFORE they even begin to show failure. You'll only know this by experience of your usage environment and as you say, get the hubs off annually and inspect all three, remove and clean brake rockers or latches and copper slip them and slow moving parts, and oil those cables annually (get them lifted with plastic tie straps so they drain every time) and eventually you'll get a pattern say bearings every 2 years, cables once a year, and brakes every 3.

I have a new trailer this year so I have a new pattern to learn all over again , but it shouldn't be to dissimilar to a trailer I had in the past.

Word of caution on bearing replacement .. I use a press to do mine, which means they come out clean and go in clean, find a local garage to do this in 2 minutes for you if you can, but the main point was, I notice some hub manufacturers state no more that 3 replacement sets are allowed per hub, as I think they get worried the o/d bearing shell will start to slip inside the hub its self, which IMHO is not all that likely, but worth noting all the same

[jyasaki]

Originally Posted by al40

My theory is.....

Flushing the brakes after use and then not driving is a BAD idea... Whilst it does wash water off the brake assembly, it also puts pressure on the oil seal and could potentially inject water into the bearings. If there was any salt water lurking around (which there will be), this could potentially be forced into the bearings. As soon as there is any salt in there, games a bogie! Driving after immersion would warm things up a bit (as well as drying the brakes!) and distribute grease again.

I don't know what kind of brake flushing system you have, but I know mine wouldn't force anything anywhere. All it does is spray water around the inside of the drum, but not really with any kind of force.

Distributing the grease is the problem. Ideally, it should already be there, and not need distributing. Pressure from the rollers on the races liquifies the grease in immediate contact, and that provides your lubrication. The more grease in contact, the better the lubrication (or the less chance of underlubrication.)

Re over greasing the bearing assembly - I was reccomended not to do this when I spoke to Insespension... In reality, there was still a lot of grease in there but the area between rear of bearing and the oil seal wasn't crammed full. 2nd time I did the bearings it was!

If there's an air gap, the grease on the outside will never get to the bearings, or won't until the hub gets really hot, anyway.

(edit - For braked trailers I can see the reasoning of not having grease oozing into the brake area as it could potentially impact the braking - this may be the reason insespension voted not to full it 100% full.)

Yes, but a properly filled bearing and an intact seal won't fling grease anyway.

http://www.championtrailers.com/techsup.html#packhubs

In particular, Items 3, 4, and Note.


Luck;

jky

[codprawn]

Originally Posted by bedajim

My launch trolley has them & stainless shafts + the same on the road trailer rollers where the trolley rides. Not sure how good they would be for prolonged high speed use

Came back from Cornwall couple of weeks ago and passed 4 trailers on the hard shoulder wheels off etc one with brakes smoking badly

Well they managed on steam locos and some of those did over 100mph!!!

I think the main reason they fell out of favour was the amount of maintenance they need - but seeing how much maintenance so called sealed for life bearings need would there be much difference? I suspect not!!!

[al40]

Originally Posted by jyasaki

In particular, Items 3, 4, and Note.


Luck;

jky

Yes, I guess i did 3 - Liberal amounts of grease (couldn't actually see the bearing) but didn't absolutely fill the cavity between the oil seal and bearing the 1st time... As mentioned previously, the 2nd time it was oozing out when I pressed the oil seal in place.

The grease is fairly low viscosity so should distribute easily once the bearings move. I guess this is a mixed blessing as it means that the stuff that is packed in around the bearing assembly will also move and unless it's packed full, there will be room for water to get in if it did make it through the seal.

So - a question re bearing buddies! Does the grease pressure of the bearing buddy actually prevent water getting in through the seal? I couldn't work out how grease would pass through from outer to inner bearing on my axle (no grease path) so wasn't sure if fitting proper spring loaded "buddies" would help or not! If grease can't pass from outer to inner then the pressure would force air into the inner bearing which is presumably not a good thing!

[codprawn]

Anyone tried these?

http://www.timken.com/en-us/products...quaspexx.aspx#

Supposed to be more corrosion resistant and ideal for boat trailers...........

[Bigmuz7]

Originally Posted by al40

So - a question re bearing buddies! Does the grease pressure of the bearing buddy actually prevent water getting in through the seal?

As I said earlier not totally, but they do slow its ingress down a good bit

[Bigmuz7]

Originally Posted by codprawn

Anyone tried these?

http://www.timken.com/en-us/products...quaspexx.aspx#

Supposed to be more corrosion resistant and ideal for boat trailers...........

Those look interesting, they say its a zinc alloy I'd never of thought that would have been hard enough to be used in a bearing, yet they say you could get 5 times more life out of them ? Err I think they want to patent that then, cos thats quite a claim

[jyasaki]

Originally Posted by al40

So - a question re bearing buddies! Does the grease pressure of the bearing buddy actually prevent water getting in through the seal?

I don't think so. My take is that the BB simply creates a reserve of grease (albeit small) that is slightly pressurized so that any grease loss is compensated for (i.e grease loss is replaced by grease rather than air.) It *may* tend to keep water out, but I don't think that was a primary design criterium. The grease is supposedly held at a 1.5 to 2 psi pressure, which will be overcome in very little water depth. So, probably not really useful in stopping an inflow of water at realistic launching depths.

Lets see: 14.7psi at the surface, twice that at 33 feet, so 2 psi would be applied at 4.5 feet. Deeper than I would have guessed, but that assumes the 2 psi part is right. The spring in mine are pretty wimpy.

jky