Trailer bearings

[poledark]

Picking up on Chris' topic, why is it that trailer bearings seem to wear out so easily? Modern car bearings seem to last forever, so why not the ones on a trailer?

 

Den

[ColinW]

Picking up on Chris' topic, why is it that trailer bearings seem to wear out so easily? Modern car bearings seem to last forever, so why not the ones on a trailer?

 

Den

 

I've read opinions that the hot grease washes out when the trailer is submerged after a long tow, but I think it's more a case of the water that gets into the bearings emulsifying the grease and that makes it useless.

[chevin]

I've read opinions that the hot grease washes out when the trailer is submerged after a long tow, but I think it's more a case of the water that gets into the bearings emulsifying the grease and that makes it useless.

 

Using bearing buddies can resolve that problem and there are types of grease that stand up to water better than others. I also keep my tyres slightly over inflated so that less heat is generated by them. Properly loaded wheel bearings shouldn't generate any heat - those on trailer wheels are hardly high revving bearings. Being as they are often dunked in water and then left for weeks before the trailer is used again, they will soon corrode if watere does get to them, so they require a lot more maintenance than car wheel bearings but few of them ever get it.

[poledark]

Not sure of the logic there re immersion. Car/lorry bearings are subject to spray (sometimes under considerable force) and they seem to last forever nowadays.

 

"Sealed for life" bearings are generally completely waterproof.

 

Den

[chesters1]

the police are certainly hot on bearings in their annual concentration outside council tips and the motorway services.

most trailers sit for months so can suffer from semi seized bearings due to lack of maintenance or neglect ,strangely though on servicing many trailer bearings (boat ,caravan,ordinary and agricultural trailers and some other types) i have never seen a sealed bearing (perhaps a modern thing?) due to most being "split" bearing types for ease of assembly at the factory.

the honda has "sealed" bearings that rust very easily water can get in but the seal makes it harder to get back out

if you think about it the modern lack of grease nipples ensure the "after" part market has plenty of money coming in

 

we replaced a bearing in my sons car ,"sealed for life" was hardly that and only the help of heat and a ten ton press got them out! i suspect the car makers are building in the use of garages (hopefully in their case the one selling the car ensuring it uses "real" parts not pattern ones) like printer makers now make profit from the carts rather than the printer

Edited October 19, 2009 by chesters1

[chevin]

Not sure of the logic there re immersion. Car/lorry bearings are subject to spray (sometimes under considerable force) and they seem to last forever nowadays.

 

"Sealed for life" bearings are generally completely waterproof.

 

Den

 

 

Hmm, there are a couple of misconceptions here. Immersion is totally different to spray from the wheels. Spray is thrown away from the hubs and so very little of that water would ever get near the hubs let alone the bearings. The bearings in a boat trailer wheels are generally two tapered roller bearings and they are not sealed. The tapers of the bearings are opposed so that the axial loading is achieved by tightening up the castellated nut on the end of the stub shaft. If you have a rear wheel drive car, you will be able to see that nut if you remove the dust cover in the centre of the front wheel. The nut will be secured by a split pin. For normal road use, the dust cover is sufficient to keep the bearings dry and clean, but if the wheels are to be immersed in water, then a seal must be used at the inside end of the stub shaft. Bearing buddies also give a seal at the outside end of the axle and by virtue of a grease nipple in the bearing buddy, you can put grease into the bearings at a positive pressure which also helps keep water out of the bearings. Just bear in mind the fact that if the bearings are under one foot of water, they are being subjected to a pressure of eight ounces per square inch of pressure by that water. It doesn't souind a lot, but any pressure of that nature is a threat.

 

Having worked for and fitted bearings for SKF for around ten years, I can assure you that "Sealed for Life" bearings are not permanently waterproof. They certainly resist intrusion but they cannot be relied upon 100%.

[Chris Goddard]

My bearings are just common or garden roller bearings! Not immersed in anything other than grease? I can understand the water thang, but just normal wear and tear? And at £15 each for the bearings for this trailer (JUST the outer) And I can get a similar sized one for an LDV for £2.50?? Where is that logic?

[chevin]

My bearings are just common or garden roller bearings! Not immersed in anything other than grease? I can understand the water thang, but just normal wear and tear? And at £15 each for the bearings for this trailer (JUST the outer) And I can get a similar sized one for an LDV for £2.50?? Where is that logic?

 

Have you tried going to somewhere like Halfords? We have similar outlets here in Oz and you can pick up a set of bearings quite cheaply. I recently bought a new hub complete with seal, wheel nuts, dust cap and bearings for $55.00 - probably somewhere around 25 quid. I know that when I first came to Oz, I could buy a set of trailer wheel bearings form Marlowes - which was our Halfords - cheaper than I could buy them from SKFs when I worked there.