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Old 06 August 2008, 14:42   #11
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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.)
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Old 07 August 2008, 01:49   #12
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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
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Old 07 August 2008, 02:48   #13
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=> 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
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Old 07 August 2008, 12:00   #14
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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.)


Quote:
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.


Quote:
(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
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Old 07 August 2008, 12:58   #15
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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!!!
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Old 07 August 2008, 15:28   #16
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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!
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Old 07 August 2008, 22:01   #17
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Anyone tried these?

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

Supposed to be more corrosion resistant and ideal for boat trailers...........
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Old 08 August 2008, 02:45   #18
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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
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Old 08 August 2008, 02:48   #19
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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
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Old 08 August 2008, 11:27   #20
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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.

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