Allo Allo folks
Bennie contacted me today and asked to post some tips on trailer maintenance...so let start with the axle and bearings
- I have to agree that some trailer manufacturers skimp when it comes to fitting the axles. I feel a lot safer having an axle ( and relevant size bearings) that can handle more (30-50%)than the GVM of the rig. It may be overkill but i do feel safer towing long distance through pothole infested Africa with something that can take the punch.[/*]
- You can aslo find , when buying second hand , that the previous owner wanted to save some bucks and went for a axle that will "Just" handle the load.[/*]
- If the axle has been through any bearing failure you HAVE to check that journal for damage/scoring to the seal seating area. Any damage here is going to chow the seal and in comes the water.[/*]
Right now for da bearings
What causes failure. In my experiance the main factors are A) Water into the hub B) lack of lubrication and C) poor quality bearings.
Lest start with lubrication(or the lack there off).
When the bearing is supplied it, is sealed in a plastic packet with a light coating of oil.The bearings have to be handled with clean hands and in a clean enviroment. Any grit or sand on your hands will transfer to the new bearing when packing ,and this can lead to premature E.......Failure
The bearings have to packed with a WHEEL BEARING GREASE so that all the void spaces between the bearing cage and the rollers are filled.
Now this is where some shops fail due to lack of supervision. They have a labourer doing this manually and it is not always checked that it is done properly. Its a K*K and messy job and when you doing bearing after bearing you get kind of gatvol...If that bearing is not packed properly with grease its going to cause damage to the race and roller in the first few K's of usage and it is just down to hill from there.Pretty soon you going to be stranded.
Even a poor quality bearing will last a long time if it is packed properly.I have seen cases where cheap bearings have out lasted top quality just due to the packing process being done properly.
Water ( specially seawater). How does it get into the hub , it is mos suppose to be a sealed environment?
Once the bearing caps have been removed , DO NOT RE USE THEM. Make sure they fit new ones. When removing them they get damage as the get moered out with a hammer (and sometimes a chisel)and the get dinged and dented. They will not seal properly, thus letting in water. When fitting new caps you can use some locktite to get a better seal.
Lets move to the seal(always fit new seals when doing bearings)
Damage can be caused to the seal by the journal(shaft).The Axle is made out of cast iron and the journal ends up rusting over time.This can score the seal and water will go in. If this is the case then you can take the axle to an engineering shop and have a stainless sleeve fitted over the journal(you would need a seal with a slightly larger ID to accommodate the sleeve)
Another form of damage to the journal is mentioned in point three of the axles section.IF you had a collapsed wheel bearing at speed , 9 out 10 times the journal will be damaged , thus affecting the sealing ability of the seal
Another way water enters the hub is when a hot hub(especially braked trailers) is submerged . The cooling effect of the water creates negative preasure and water will come in via a damaged seal or ill fitting bearing cap. Apart form waiting and hour or so for your hubs to cool there is not much you can do here.
Another way the water enters the hub is when YOU clean the trailer.NEVER EVER use high or direct pressure on the seal... a light mist spray or wipe with a cloth is fine. Using high pressure water can drive grime/water under the lip of the seal and that can cause damage to the seal , which will lead to water entering the hub.
Another form of water in the hub is condensation.This is minimal and not usually terminal. Most good quality WB grease have water resistant properties that will handle this small amount of condensation
The bearings
This is the difficult one to monitor and you have to deal with a reputable serving agent that can be held accountable should the paw paw hit the fan. There are guys out there that will charge you for a good bearing and fit the K*K one
Insist on getting your old bearings back and they must be placed in the packaging of the new bearings. You now know that they DID actually change the bearings and that you have proof of what they fitted. Also Keep your job slip /invoice.
If you want peace of mind, fit a bearing protector.There are various models on the market and they suit all types of budgets.
If you going to order bearing buddies from the states , double check your sizing , they are imperial and we are metric.In my experience they only cover insurance to the point of entry (ie JHB) , if they get lost after after that , its your problem
If you get the plastic one's , by another set as spare.They do tend to crack or fall of over time, thus leaving and exposed bearing(normally at the wrong time).If this happens , don't just fit the new bearing protector and carry on .The bearing must be cleaned and repacked.
A bearing protector's function is
- Keep the bearings lubricated and make servicing a two minute job.All you need is a grease gun[/*]
- If there is any damage to the seal the bearing protector will highlight this. It will push grease through the seating area of the seal and you can attend to the problem.[/*]
- The bearing protectors maintains positive pressure in the hub , and thus ( if under load/ pressure ) should not allow water into the hub when submerging a hot hob[/*]
- Creates a barrier(a wall) of grease between the seal and the bearing , thus making it difficult for water to get to the bearings(in a damaged seal scenario)[/*]
I have some more info on my FB page , but i will continue on the morrow with some more tips.Will cover grease( and the misconception that it actually melts in the hub during use) and storage/towing tips
Have a good evening ( and please excuse the spelling )
Best regards
Rob