wheel nuts coming loose

[PaulAnderson]

I had a lovely 200 mile top down trip in my TR4A IRS at the weekend but an old problem returned. Relatively early on my trip I heard a gentle kocking but only at low speeds and certain conditions. Over time I began to suspect what it was which I confirmed by taking a wire wheel off and checking the tighness of the nuts on the wire wheel adaptors. My suspicions were confirmed when two were found to be slack and partly loose. I'd had this problem a while ago and had changed both the adapters and the nuts to no avail, eventually putting some nut lock on the threads. Obviously this has worn off and the nuts started to come loose again. After a quick tighten up I was on my way again, until next time.

 

But, why do the nuts come loose, and only on the back wheeels? Anyone else have this problem?

 

Paul

[BrianC]

Tedious as it may be, I suspect you will need to change the studs as well.

(Assuming you are torquing them correctly.)

 

I don't suppose there are two different but almost identical threads amongst the repro nuts? - e.g. metric and imperial.

[PaulAnderson]

Tedious as it may be, I suspect you will need to change the studs as well.

(Assuming you are torquing them correctly.)

 

I don't suppose there are two different but almost identical threads amongst the repro nuts? - e.g. metric and imperial.

 

The replacement nuts I think came from Revington and I explained my problem to them at the time so I'd hoped it was sorted. Maybe it is the studs which I've never touched, but I hope not.

Paul

[Steve R]

Hello Paul

I know you have changed both the nuts and adapters, but i will throw this in anyway, i had a problem when the chamfer on the nuts did not match the chamfer around the holes in the adapter, the nuts would then bottom out on the hub, without gripping the adapter, the movement on the adapter would then loosen the nuts.

Regards

Steve

[ianc]

On the front wheels, torque is applied in one direction only - when braking.

On the rear wheels, torque is applied in one direction when accelerating and in the opposite direction when braking. This, allied perhaps to the other possibilities mentioned already, may account for the problem occurring solely at the rear.

Ian Cornish

[PaulAnderson]

Hello Paul

I know you have changed both the nuts and adapters, but i will throw this in anyway, i had a problem when the chamfer on the nuts did not match the chamfer around the holes in the adapter, the nuts would then bottom out on the hub, without gripping the adapter, the movement on the adapter would then loosen the nuts.

Regards

Steve

 

A good suggestion Steve. I have a very strong recollection that the old and new nuts did have a different chamfer but unfortunately both seemingly have given the same symptoms - it was about 5 or 6 years ago that I changed them alongside the adapters themselves so my memory is a bit vague. I recall taking a photograph of the two profiles alongside each other but can't find that on my PC which is unusual as I'm very tidy on the computer (though messy everywhere else). Perhaps I should send away for another set of replacement nuts from a different supplier, in the hope that they're different.

Paul

Edited October 7, 2009 by PaulAnderson

[Alec Pringle]

Hi Paul,

 

if nuts come loose they tend to 'chatter' on the thread, with resultant wear to both the stud and nut threads . . . . and possibly to the nut seat in the wire wheel adapter.

 

Replacing nuts with new ones, nice tight thread, is then only a temporary improvement - stud thread wear will allow the nuts to loosen, more 'chattering' and the wear process continues again . . . . thread locker won't compensate for well worn threads.

 

Probably your solution will have to be new nuts and studs, and possibly the adaptors too if the nut seat has been worn out of true. Rear problems are more common than front for the reasons Ian suggests. It's worth checking your wheel bearings too, any wear here will only exacerbate the problem.

 

Cheers,

 

Alec

[4Mal]

I had a similar problem but it had worn the adaptor nut seat so badly it was never going to tighten again...in fact the stud holes and seat had become slightly oval due to the chattering. New studs and adaptor were required in the end.

Put me off wires and adaptors - Now on Minilites!!

[Steve R]

Hi Paul

I found that the adapter chamfer was worn, and because it was loose the holes had enlarged, I nearly lost the rear wheel as one stud sheared and two others pulled out so i had a trip home on a transporter. I fitted a new hub and new nuts, but you could tell that the adapter wasn't being nipped up tight enough.

A previous owner had fitted new studs and tightened them up with a screwdriver , one of the many examples of his workmanship i had to correct.

Steve

[Mikell]

Hi Paul,

I too had the same problem as you, and with cause same / similar as Steve has outlined. In my case the rear wheel started knocking loudly with no prior warning at about 40 mph. Handling went well wrong, and I slowed to a standstill without daring to brake. On roadside investigation, the rear wheel was unbelievably loose even by me just 'hand wobbling' the tyre top. On removing the wheel, 2 of the studs were 50% undone .........the other 2 had sheared off completely. The RAC low loader man then arrived, and was amazed that I hadn't had a more unfortunate event. Just the day before I had been "challenging the national speed limits" - say no more, I suspect I was very lucky.

 

The 4a had only a couple of weeks previously been serviced by a recognised TR specialist including fitting of 2 new half shafts together with new studs etc. The specialist subsequently examined the remains and after close examination declared a 'bad batch' of studs wherein "the camber on the shoulders were adrift by a miniscule amount". This poor seating apparently allowed the studs to loosen - with the results as previously outlined. The original studs were then re-fitted, and no further problems either of wheel loosening or of trouser soiling have been experienced. I understand the 'rogue batch' studs was returned with appropriate coverage.

 

Hence I suspect the moral of the story is that new studs etc should not be taken for granted ................ for goodness sake check a complete seating is achieved and maintained. Such checking may seem over the top - maybe I'm a sad git, but I do now.

 

Cheers,

Mikell.

[Alec Pringle]

At the risk of stating the obvious, and/or teaching grandad to suck eggs.

 

The only situation in which you can realistically have confidence with replacement wheel nuts and/or studs is when fitting a matched full set of OE studs and nuts to a hub. Even then I'd be cautious, how worn is the hub ?

 

Anything else is potentially dubious - as in aftermarket alloy nuts, new nuts on old studs, pattern nuts, repro studs, fitting one new stud/nut of 4 etc etc. Fit the item/s, torque up to the correct figure, test drive and retorque after 10 miles, repeat after 100 miles. Only then can you be reasonably confident that it's a satisfactory fitment.

 

Cheers,

 

Alec