Wheel studs and threadlock
Seeking opinions please.
It's usually a catastrophe if a wheel comes off on a single axle van and when I removed my wheels for new tyres I noticed the conical stud threads had remnants of a white substance. Closer inspection and it looked to be thread lock had been applied, anyway I shall also be applying some threadlock before torquing the wheel nuts.
Good or bad idea? remembering I don't have additional shock asorbers fitted to the van so plenty of 'jarring' of the ALKO suspension. I'll also permanent pen mark the stud heads as the plastic retainer clips you can buy won't fit the recessed stud heads in the alloys.
More interested in keeping the wheels secure (have never had a problem) rather than thinking how I'm going to remove them next time, I'm sure the threadlock seal will break 
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The wheels come loose long before the bolts turn, so thread locking will not stop the wheel coming loose. It might stop the wheel coming off until the loose wheel thrashing about destroys the bolt shanks, or you hear the racket and stop to investigate.
Far better buy bolts with much greater energy storage that hold the wheel clamped up, and not getting loose in the first place. Address the underlying problem.
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The wheels come loose long before the bolts turn,
Not quite sure how that happens. For the wheel to become loose, either the nut/bolt HAS become loose to some degree, or somehow the area of the wheel that the nut tightens up to has become thinner. The bolt coming loose is more likely.
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I used thread lock on my towbar after the bolts came loose, but make sure you use the correct grade.
I don't see why you can't use thread lock on the wheel nuts, but again make sure you buy the correct grade.
Different grades are used for certain applications, some need more torque to loosen than others, something you need to consider if you get a flat tyre.
My Valencia model is noted for losing wheels, which prompted Bailey to recall the studs for changing to a higher torque version, now 160nm, was 120nm i believe with the original bolts.
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Only for those that want to gain a better technical understanding of how our wheels are retained I will try to explain in simple terms:
The wheels of our caravans are held in place solely by being clamped to the hub[Drum].The bolts create the clamping force by being torqued up and being stretched within their elastic range ie they are tensioned so store energy.
Unfortunately, the contact surfaces of the wheel, the hub, and the threads themselves are not always perfectly finished to be able to take both the bolt clamping force and the other additional cyclic and shock forces generated by rolling along the road, bearing the van’s mass. Quality of machining, surface finishing [plating and paint] and contamination all can yield a bit and contribute to minute amounts of settlement.
That is fine if the bolt has enough stretched length to store sufficient energy that the clamping forces remain well able to hold the wheel exactly where it is intended to be. But, any settlement will start to deplete that stored energy, and so the clamping forces.
Should that clamping force be depleted to a value lower than needed to hold the wheel tight enough to resist all the forces, the wheel moves, ie it is loose.
As stated it can become “loose” long before the bolts have turned undone at all.
Once it moves things go rapidly wrong, wearing the moving surfaces losing more clamping and the bolt function then goes from clamping to attempting to physically retain the wheel. Once the tension is lost to an extent a bolt is no longer in tension even momentarily, it starts to undo; though as said the wheel had come loose before that can happen.
The classic approach engineers take faced with these risks is to make the bolt more elastic, ie able to store more energy to retain the clamping forces needed, even with slight settlement. A way this can be done is to design a longer section of bolt storing the tension. In many cases the easiest way is to simply put in a spacer and use a longer bolt. Eg as the WSL caravan bolts offered as an upgrade for our Al-Ko wheel bolts. These increase the stretched part of the bolt by about three times so that alone can store three times the energy and live with much greater surface settlement before the required clamping forces are lost. WSL also use a steel able to take higher stresses so the tension increase as well.
Locktight or mechanical anti turning devices serve no role in holding the wheel tightly in place, only once the wheel has come loose they offer just a bit more resistance to the wheel coming off. But little, as by then the wheel is smashing about violently, wrecking the bolts in a short time.4 -
Let's assume I have no underlying problem as I haven't lost a wheel in the 3 years I have had the van, and it's travelled many miles both here and abroad. Also all wheelnuts were nice and tight when removing for new tyres to be fitted.
Let's also assume that all mating surfaces are OK, so would threadlock be an advantage or not?
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No, because as you have found you don't need it, and as I said the problem if it happens, occurs before there is the slightest hint of a bolt undoing.
You probably will find that the handbook does not tell you to use it.
Will it do any harm, See edit.
Keep the Locktight for intended applications and importantly re-torque the bolts after 20 miles first on the road.
Edit: on rethinking the Locktight completely screws up that vial re-torquing so would be dangerous in this application as you can't correct the initial in use settlement.
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But this is why I am asking, because as stated in my original post I had remnants of a loctite composition on the threads and have been running with this. This could only have come from the 3 warranty services I have had, so are the dealers applying it and is it off their own backs or perhaps a memo from Lunar.
If when I removed the studs they were clean then I wouldn't be asking the question.
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I can't help you more; I have given you the engineering facts. Ask the dealer who puts the stuff on how the user could then possibly re-torque up the jammed up bolt to take up any mating surfaces settlement?
Obviously they will completely fail to give a sound answer, as you can't re-torque to the correct value because of the extra viscous drag from the goo.
Sadly, this is the standard of the after market leisure "industry" we have.
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I have never lost a wheel, and only recently in the last six years started to use a torque wrench.
What i feel is extremely important is that the mating surfaces are clean and rust free to maintain as flat a surface as possible.
A torque wrench is also useful giving the extra leverage to obtain the 160 nm my bolts require.
Because i regularly remove my wheels, yearly to store the wheels, and after every service to reapply the copper grease and ensure the surfaces are upto my standards, i don't use thread lock, and i don't bother to recheck the wheel bolts after 20 or 30 miles either.
Before other's post i shouldn't be using copper grease, and i should be checking bolts after 30 miles, i know, but chose to use my own tried and tested methods used over the last 46 years, where i have never lost a wheel on car or caravan.
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That's it xtrailman, your opinion and your choice also agree on the cleanliness of the mating surfaces.
I have had second thoughts now about adding Lockthread after coming across a Bailey document, where in my case it might not be remnants of Loctite but a dry coating of PTFE baked onto the bolt threads when manufactured. The remains I saw could be the unused part of the thread which does not enter the hub.
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Have got the correct bolts?
The chamfered face on the bolts, fits into the chamfered hole of the wheel and must be the same angle, especially on alloy wheels.
Just a thought
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Could the "white stuff" be oxidisation????
just another thought
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Thanks for your input Gc, but the van is nearly new and the studs are original.
The studs themselves are in mint condition, and its only that I removed the wheels to get new tyres put on that I noticed some white coloring on a small portion of the unused thread. I think now it was not a loctite solution but something from new and maybe manufacture.
Whatever, I will just wire brush the threads, clean the mating surfaces and dry torque to the 115nm that the previous service record states.
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That sounds reasonable, I wouldn`t advise on using any lock fluid or grease on any part of the wheel fixings.
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Wow! couldn't of put it better myself ..... But in my experience , I would advise Dave fl2 , check the torque every trip , and after a short while after the wheels have been off , I do and I'm a lazy b . No locking compound or bright yellow things are needed
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