Just been putting some locking wheel bolts on my caravan alloy wheels and on trying to remove one of the existing bolts on all four wheels they were a bit stiff to remove (a lot stiff slightly seized).
So when I placed the locking bolt on I smeared a small amount of grease on the threads so removal will be a tad easier as many years ago I destroyed a locking wheel bolt when it seized on, and what a mare to remove I tell ya.
I have read mixed reports about putting a small amount of grease on wheel bolts, and would like to know you opinions !
Chris..............
------------- FINE PRINT: I reserve the right to be wrong. Should you prove me wrong, I reserve the right to change my mind.
As I understand it wheel bolts should be torqued up with clean dry threads.
But I've experienced apparent seizing where alloy wheels are concerned except when I was the last person to tighten them. I do use a torque wrench at home.
always used just a tiny smear of copper grease on the seating face, not the threads, on all my cars, caravans, motorbikes, and trailers, not had a problem yet.
The reason why you should not put grease on our caravan wheel bolts is that AL-KO dont quote you the correct torque up figure for "lubricated" bolts only for "dry" bolts.
Lubricating the bolts results in a much greater tension being developed in the torqued up bolt than is the case where they are torqued up dry, to the same torque.
These wheel bolts are already designed to be at very high stress levels and lubricating them can increase that stress by up to 20%. This higher stress level coupled with the fluctuating rolling induced loading puts them in danger of fracturing in the thread roots. This is an area where I have quite a lot of design experience. Whilst I wish they did quote the right wet toque up value as it normally yields greater consistency, they dont. To use the specified torque up with a lubricated bolt is being extremely ill informed.
no mention of lubrication here but as retired motor engineer i can say it is not a good idea to add grease of any kind to a wheel bolt because it will lose tension and grip.see
I would'nt lubricate wheel studs/bolts. Either tighten with a torque wrench of just do up firmly with a wheel brace if you understand how tight they need to be. Keep a 2 foot long breaker bar to crack'em undone.
Quote: Originally posted by trez321 on 20/1/2010you can always use graphite
Have you checked that one out with Al-Ko; I dont think so?
It most definitely is not what I would recommend. It will lead to over stressing the bolt and is about as good an agent to allow the backing off of the bolt as I could think of*. Not a good recommendation at all.
Edit: * with the possible exception of a PTFE spray?
Hmm, looks like I have done the wrong thing then,
Will have to remove them and clean it off.
At least there is another 4 bolts to hold the wheels on ! LOL !
Thanks all.
------------- FINE PRINT: I reserve the right to be wrong. Should you prove me wrong, I reserve the right to change my mind.
Whilst Alko specify the tightening torque for clean dry bolts, they are referring to new bolts. Once they have been in service and the slightest bit of rust builds up, the nut becomes tighter in the thread and therefore the tightening torque is different.
A small ammount of lubrication will overcome the rust build up. An example of this is that if you take a new nut and bolt, the nut will spin up the bolt easily. If you take the same size nut and bolt that has been outside for a few months, it is a very different story. Imagine how much different it would be if it was repeatedly heated and left to cool and had been outside for a few years as is the case with a caravan. If you also took the same nut and bolt, covered it in grease and left it outside for a few months, you would find the thread resistance on the greased bolt to be far closer to that of the new one than that of the rusty one.
The biggest issue I have come across with alloy wheels is not with the nuts seizing up, but the wheels corroding onto the hubs.
Its not a grey area, its a don't do. Its very important to have the correct torque on a caravan wheel which is why engineers pay a lot of money for calibrated torque wrenches.
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Topic: Wheel bolts Grease
