# Loose wheel bolts after service and MOT: any thoughts?



## Phil42 (Apr 4, 2006)

Any ideas about this?

My 03 V70 had an MOT and service at a garage we have been using for 20 years. The boss is a really nice, helpful, honest guy and all the staff have been the same. I picked the car up Friday evening. Couldn't get there till just after they closed so he left it outside.

I then drove home, mostly along the M60 at speed. When we came off the M60 I heard sounds clearly related to the wheels but couldn't identify them. When I got home I noticed that as I braked there was a pronounced noise from the from the nearside front wheel. On checking I found that all 5 bolts were not even finger-tight.

I've managed not to dwell on what might have happened but clearly I'll have to let the boss know that someone has made a potentially dangerous error.

As I understand it they do not remove wheels for the MOT but I assume it must have been removed for some part of the service. It would be too much of a coincidence for this to have just happened at the time it was serviced.

Any thoughts?


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## erneboy (Feb 8, 2007)

They must have had it off, they don't just come loose. I'll be amazed if it hasn't knackered the studs/bolts and the rim.

I wouldn't give them the chance to deny it. I'd just say "You didn't tighten the wheel properly and now there's damage which you'll have to fix."

Don't drive it back. Check for damage, once there's a bit of wear it's virtually impossible to retighten effectively. It may be possible to drive for a short distance but it's not really safe and will soon come loose again.


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## Phil42 (Apr 4, 2006)

Thanks for that Alan. It makes sense. I hadn't really thought about damage as the bolts seemed to tighten OK. You're probably right about not driving it.


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## Jimblob44 (Oct 26, 2013)

Just make sure that as it had been "left outside" the garage that some ne'erdowell hadn't tried to steal the wheel, if the garage was closed and no one about it may have been tempting for some miscreant ? I know that when I had parked my van outside a friends house for a week or so we had a neighbour warn us of some travellers showing more than a keen interest in the van and had it not been for the neighbour going out and chasing them who knows what they would have done?

You really need to give theguys at the Garage an opportunity to explain (if indeed there is an explanation that would shed light on a possible serious accident)

Jim.


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## erneboy (Feb 8, 2007)

Yes they do tighten Phil, but you are almost certainly tightening using a damaged nut/bolt onto a damaged rim. If the taper on the nut isn't a perfect fit into the taper in the rim you won't be able to tighten it so that it can't move. When it moves, which it will, the process of eroding the rim and studs to bits will continue till the studs/bolts fail and the wheel comes off.

All of that assumes there's damage, but given your description of what happened I feel that's certain, Alan.


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## Phil42 (Apr 4, 2006)

Jimblob44 said:


> Just make sure that as it had been "left outside" the garage that some ne'erdowell hadn't tried to steal the wheel, if the garage was closed and no one about it may have been tempting for some miscreant ? I know that when I had parked my van outside a friends house for a week or so we had a neighbour warn us of some travellers showing more than a keen interest in the van and had it not been for the neighbour going out and chasing them who knows what they would have done?
> 
> You really need to give theguys at the Garage an opportunity to explain (if indeed there is an explanation that would shed light on a possible serious accident)
> 
> Jim.


Thanks Jim. We collected about 20 mins after their closing time so very unlikely. Not sure it's a wheel anyone would want.

The only explanation I can think of is that someone put the bolts back on and then, for some inexplicable reason, didn't do the final tightening when it was down on the ground.


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## erneboy (Feb 8, 2007)

Check your servicing receipt and see if they did anything that would involve removing the wheel.

If it doesn't make it clear ask if they checked the front brake pads. If they say not ask if they had any wheels off for any reason.

I had assumed it was on their premises when I replied first time. Was it there overnight? Or delivered and collected the same day. Either way it was in their care.

Most garages do their best. Though I once drove my bosses car during a summer job. It was metal to metal on the front discs. I told him and he remarked that it had been serviced the previous week by a main dealer (Saab). We found the receipt and the cheeky buggers had charged him for fitting front pads. I don't think even they did that on purpose but it was pretty bad, and my boss was a car numpty. He would just have driven on thinking that as it had been serviced it must all be OK.


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## Phil42 (Apr 4, 2006)

Haven't seen the receipt yet as I haven't paid yet - fortunately, as it turns out.:smile2:

There might be a service checklist in the handbooks. I'll see. As I say, he's an honest guy. If they had the wheel off I don't think he'd deny it.

Main dealers? Haven't touched them for many years. But I guess this experience suggests things can go wrong anywhere.


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## erneboy (Feb 8, 2007)

Yes. Anybody can make a mistake. It's how it's dealt with that matters.


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## vicdicdoc (May 14, 2005)

I've had a wheel nut come loose . . . Hence my advice on the bottom of every one of my posts.


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## Spacerunner (Mar 18, 2006)

vicdicdoc said:


> I've had a wheel nut come loose . . . Hence my advice on the bottom of every one of my posts.


I always thought you were referring to testicles! 
Just shows how wrong I can be!


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## greygit (Apr 15, 2007)

As an ex mechanic I would say the garage owner/manager wouldnot deny responsibility for loose wheel nuts after a service as this does happen, unfortunately.


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## Phil42 (Apr 4, 2006)

Thanks. Any comment from your perspective on the possible risk in driving the car a short distance, after tightening the nuts, to see if they stay tight?


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## Pudsey_Bear (Sep 25, 2008)

I'd ring them and ask what jobs they did on the car before mentioning the problem or asking about the wheel, then when you know for sure they've had that wheel off for whatever reason mention what happened.

If you have a call recording app on your phone, set it to Auto record.

I use *this one* there are others, not sure if you're still required to mention that the call is being recorded, or when, I usually forget to mention it as it's on all the time, useful app for having detail later, as you don't need to write anything down.


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## Mrplodd (Mar 4, 2008)

If it's an alloy wheel then it will, without doubt, be damaged beyond repair, if it's a steel wheel then I would take one of the bolts/nuts off and look at the size of the hole in the wheel rim. If elongated or oversized, don't drive it. The wheel is made of much softer material than the stud/bolt. If the threads on the stud/bolt are at all damaged DONT DRIVE IT, 

If it was me I would insist the garage come to collect it.


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## Pudsey_Bear (Sep 25, 2008)

Mrplodd said:


> If it's an alloy wheel then it will, without doubt, be damaged beyond repair, if it's a steel wheel then I would take one of the bolts/nuts off and look at the size of the hole in the wheel rim. If elongated or oversized, don't drive it. The wheel is made of much softer material than the stud/bolt. If the threads on the stud/bolt are at all damaged DONT DRIVE IT,
> 
> If it was me I would insist the garage come to collect it.


Agree, but would have said.

If it was me I would insist the garage come to recover it.


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## Penquin (Oct 15, 2007)

It will be interesting to hear what develops and how it is dealt with....

wheel nuts are very important and they should be done up to the correct torque value - if too loose then the problems recounted above could be the problem, r even worse losing a wheel when at speed (happened to my father many years ago and the loose wheel overtook them.....

similarly if too tight the studs/bolts can be damaged resulting in exactly the same thing -that happened to ambulances in the West Country a few years ago when the bolts were put on using an airgun - way too tight and the threads were dmaged. This resulted in a wheel coming off one ambulance when at speed with a patient on board who was sadly killed by the resulting rolls of the vehicle.... the crew were also seriously injured....... 

So as so correctly said "keep your nuts tight, but not TOO tight"

Do you know the correct torque value for your wheels? ould you apply it or is it a case of "as tight as I can and then stand on the brace?"

Dave


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## Phil42 (Apr 4, 2006)

I should stress that this is a very reputable garage. I totally trust the guy and so do a lot of other people. So no need for recordings though I can see they could be useful in other circs. I expect they are alloys so I expect _him_ to tell me not to drive it.


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## Phil42 (Apr 4, 2006)

Dave - your last para applies.


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## Pudsey_Bear (Sep 25, 2008)

Phil42 said:


> Dave - your last para applies.


I think that might be too tight but stand to be corrected.

I just lean on mine with my weight over the wrench, then check again after few miles.


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## greygit (Apr 15, 2007)

Phil42 said:


> I should stress that this is a very reputable garage. I totally trust the guy and so do a lot of other people. So no need for recordings though I can see they could be useful in other circs. I expect they are alloys so I expect _him_ to tell me not to drive it.


*Yep, I think you're right you shouldn't drive it until you have contacted the garage, I suspect new wheel andstuds might be needed. :frown2:*


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## Penquin (Oct 15, 2007)

For your car;

Continental tyres torque chart

this thread has details for Fiat Ducato based MH;

Fiat Ducato based MH

Hymer?

Hymer torque settings

NB I cannot guarantee the accuracy of any of these sites and STRONGLY recommend checking.....

BUT do you have a torque wrench?

Dave


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## Dill (Jun 3, 2010)

Phil42 said:


> I should stress that this is a very reputable garage. I totally trust the guy and so do a lot of other people. So no need for recordings though I can see they could be useful in other circs. I expect they are alloys so I expect _him_ to tell me not to drive it.


Phil I would be up front with the garage as they have been with you all these years, as you say no need for recordings etc. They won't be able to tell you if it's safe to drive without seeing the wheel and studs. But i'm sure they will come and check for you and sort out any problems.

Regards

Dill


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## Pudsey_Bear (Sep 25, 2008)

Dill said:


> Phil I would be up front with the garage as they have been with you all these years, as you say no need for recordings etc. They won't be able to tell you if it's safe to drive without seeing the wheel and studs. But i'm sure they will come and check for you and sort out any problems.
> 
> Regards
> 
> Dill


I've had long term relationships with a few garages over the years, never a problem until there is one, finding out what they've done before mentioning the wheel isn't going to spoil the relations ship, they may not in fact have had to take the wheel off, it may have been slowly working it's way off for a while, and only just got bad enough to notice the other day.

If the vans not been washed for a while there will be finger marks in the dust anyway as a tell tale.


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## Phil42 (Apr 4, 2006)

Kev_n_Liz said:


> If the vans not been washed for a while there will be finger marks in the dust anyway as a tell tale.


They always wash the vehicles after service but thanks for the tip.


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## Phil42 (Apr 4, 2006)

Penquin said:


> For your car;
> 
> Continental tyres torque chart
> 
> ...


Thanks Dave. I do have a torque wrench from way back when but no idea where it is!:frown2:

It's my _car_, a Volvo V70 02. The place is an indie Volvo specialist but they do work on any vehicle.

They do my van Transit PVC and have done since 2007 (it was new in 2006). Never needed anything doing to it.

I'm not now planning to do anything myself and assuming they will come and sort it.


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## Phil42 (Apr 4, 2006)

They also know Sue and her dad (God knows how long he's been with them) and have actually known since Sue long before the dementia (which BTW is just an added complication when I need to get vehicles there and back).

Not that it makes any real difference but just realised that I've been calling it an 02 vehicle and it's actually 03 - it's my age!


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## Phil42 (Apr 4, 2006)

This link

http://www.motuk.co.uk/manual_420.htm

states that MOT includes check for looseness.

So that confirms the garage is at fault doesn't it?


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## erneboy (Feb 8, 2007)

Not necessarily Phil. A wheel could be tight enough not to feel loose without the nuts having been fully tightened. In that case it would seem OK on a quick check (MoT won't be checking them for torque) then with subsequent use it could come loose, as it did.

I'd guess that they're run up with an air gun on a very low torque setting while it's still jacked up and that the intention is to torque them with a wrench afterwards when it's on the ground. I'd say the last step was missed.

I assume that the car didn't have far to go between servicing and the MoT? Alan.


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## Phil42 (Apr 4, 2006)

erneboy said:


> Not necessarily Phil. A wheel could be tight enough not to feel loose without the nuts having been fully tightened. In that case it would seem OK on a quick check (MoT won't be checking them for torque) then with subsequent use it could come loose, as it did.
> 
> I'd guess that they're run up with an air gun on a very low torque setting while it's still jacked up and that the intention is to torque them with a wrench afterwards when it's on the ground. I'd say the last step was missed.
> 
> I assume that the car didn't have far to go between servicing and the MoT? Alan.


Alan, on last point, they do MOTs themselves. The boss and at least one employee are certified testers.

There doesn't seem to be much point in it being part of the MOT if the bolts are 'tight', even on a quick check, but loose enough to nearly come off after a few miles.


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## erneboy (Feb 8, 2007)

The point is Phil that there's tight as in apparently firmly held and then there's tight as in correctly tightened up so as not to come lose.

Think of it this way. Every time a wheel turns the forces it's subjected to go through 360 degrees, it's pushed in every direction and it's on a taper where each nut meets the rim. You won't feel a little slack there by hand or have the strength to make it move, so it won't show on a quick visual check but apply weight and revolutions to the wheel and each turn and movement causes wear. Once that starts it won't be long till it's noticeable and further tightening won't cure it, Alan.


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## Pudsey_Bear (Sep 25, 2008)

Phil42 said:


> This link
> 
> http://www.motuk.co.uk/manual_420.htm
> 
> ...


Never knew that, never ever had a wheel checked for tightness, ever, and I always wander around the vehicle to see if anything needs doing underneath.


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## Phil42 (Apr 4, 2006)

OK. Phoned first thing. Mike immediately said it shouldn't have happened, sounded concerned (though not quite as surprised as I would have expected). He said it had had front brake discs replaced and obviously someone had done the initial tightening and then failed to do the final tightening.

He apologised and said he would check it and make sure it was all OK if I take it in. I asked if this was safe and he seemed very confident that it was. He said just to tighten as much as I could and that 'you can't overtighten'. Having thought about this I reckon he's right because the head of the bolt fits into a recess as you tighten and so eventually 'stops'. If you tried hard to tighten beyond this you would end up damaging the thread which you would be aware of.

Anyway, I'm going to tighten again before I set off and re-check the other side just in case.

I'm staying off the M60 though! Hoping to be able to soon post that it's all sorted.

In the meantime, many thanks for all the help.

Phil


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## cabby (May 14, 2005)

When I was just a young chap and started work in a garage, my first position was on servicing. Then in 1972 British Leyland changed the system and we finished up with a check off page, where one ticked the box as completed. Maybe this should be reintroduced.

cabby


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## Penquin (Oct 15, 2007)

Phil42 said:


> OK. ....He apologised and said he would check it and make sure it was all OK if I take it in.....Anyway, I'm going to tighten again before I set off and re-check the other side just in case.
> 
> Phil


Just a gentle suggestion, while you are at the garage ask them what torque setting they use for your wheels - that will give you confidence that they normally do check correctly....... :grin2::wink2:

or not........:nerd::surprise:

That exercise would rapidly show how reliable they are.......

Dave


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## Phil42 (Apr 4, 2006)

Thanks Dave. Will do.

Cabby, that's an excellent method in all sorts of situations, e.g. packing MH!


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## Pudsey_Bear (Sep 25, 2008)

You can't over tighten wheel nuts, what a load of rubbish, you obviously can and is why the way wheels are fitted has changed, they now need to be torqued in line with the vehicles manual, different bolt/nut size/diameters will require a different level of torque too, there is no one size fits all, so I'd check your manual for the figure and ask what they set the torque wrench to, obviously before you tell them what it is.

I know you trust this garage, but recent events do call that trust into question, especially when it's safety related, also is this trust based on your knowledge of vehicles telling you it's been done correctly or just that so far nothing has gone wrong.


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## greygit (Apr 15, 2007)

I've notice a lot of tyre fitters are using a torque wrench now but they seem to have a one set setting for all vehicles as I have never seen them adjust it for each vehicle. As I'm ex motor trade I tend to notice things like this. :surprise:


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## cabby (May 14, 2005)

Funny you should say that. I noticed as well.I can understand with a standard car, but performance or commercial must be different.

cabby


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## Phil42 (Apr 4, 2006)

OK, the journey to the garage went very smoothly. It's quite clear that the problem had nothing to do with torque wrenches (of which more later) but was, as we suspected, a failure to do the final tightening on that wheel after the vehicle was back on the ground. I was able to watch as the guy responsible first checked the threads of each bolt on the wheel, one at a time, and then handed it to the boss to check. They were all OK. Then all the bolts on the other wheels were checked for tightness. They were all OK.

No torque wrench was used. I asked Mike what the torque should be and he told me that they tended not to use torque wrenches on wheels as they knew from experience when a bolt was tight. The wrench the guy used had a very long handle and then it was a case of tightening and then giving one more little turn. Now before you all throw up your hands in horror, I'll deal with Kev's question re vehicle experience. I've driven and owned a large number of different vehicles (mostly cars but including two VW Transporters) for more than 50 years. For most of that time i've done the vast majority of servicing and repairs myself. I have replaced an engine and a couple of gearboxes, worked on brakes, fuel pumps, various kinds of joints etc. I've changed many, many wheels in my time - remember when we were advised to rotate tyres? I have owned a torque wrench (it was needed for some vital bolt or other) but hardly ever used it. None of my wheels ever came loose, never mind fell off. I'm not sure that my garage is particularly unusual and I'd suggest that it would not be as popular as it is, they moved into larger purpose-built premises during my time, if their method of tightening wheel nuts/bolts was inherently unsafe.

Having said all that, this incident has shaken my confidence a bit and they are maybe 'on probation' with me for a while.

It's actually a drag travelling into Stockport in my present circumstances - I have to get someone to look after Sue or get a lift (there or back) each time. We used to go on the bus but the walk from the bus to the garage involves a steep hill and is not feasible with Sue now. There is a garage within 5 minutes walk of the house and it has a very good reputation so there may well be a time before too long when I give them a go.

Thanks again for all your help.

(The last two posts - which I've just clocked - tend to suggest that many garages are not even using their torque wrenches properly!)


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## emjaiuk (Jun 3, 2005)

greygit said:


> I've notice a lot of tyre fitters are using a torque wrench now but they seem to have a one set setting for all vehicles as I have never seen them adjust it for each vehicle. As I'm ex motor trade I tend to notice things like this. :surprise:


The specialist tyre fitters I habitually use always either check or more often alter their torque wrenches for every car. There must be several settings otherwise I wouldn't see them altering them so often. Having said that, I've never used a torque wrench on wheels myself.

A related story, many many years ago my business partner borrowed my car to go skiing. Whilst in the French Alps, he had cause to remove the wheels to fit chains, as was common in those days. On his return we swapped cars and about two weeks later, one of my wheels came loose whilst driving. Just goes to show how long it can take to work loose!

Malcolm


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## Penquin (Oct 15, 2007)

Thanks for the update, the important thing is that you and your vehicle are OK and there is no damage to either! The damage to the garage's reputation can only be improved by time and experience.

Like you, I have also swapped wheels frequently and never used to use a torque wrench - until the problem that I mentioned earlier with *OVER TIGHTENING* the bolts became known amongst those of us driving ambulances - it is a tad disconcerting to have heard about the fatality and to have realised that "there but for the grace of God..........".

Since that time it has become part of my "normal practice". I suspect that if the wheel *HAD *parted company and there had been an accident with perhaps serious consequences, VOSA and probably the HSE would have taken a very different view of his "_knowing from experience when a bolt was tight._" but fortunately it did not get that far due to your vigilance.

Dave


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## cabby (May 14, 2005)

I thought that I would have to change garages, but after a chat it turned out that one of their staff lived local, so we arranged for them to collect and deliver, no extra charge. Have a chat with them and see if they can accommodate you.
Or change to that local garage.Make it work for yourselves. 

cabby


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## Jimblob44 (Oct 26, 2013)

When I was still working I used a local garage (well, I still do) and recommended them to the other members of staff, within a year or so nearly everyone had used them for one thing or another and instead of worrying about getting time off work to drop off/uplift a car the garage always sent someone to our workplace to uplift the car and then drop it off again at home time, nothing was too much bother and the prices were fair. I would ask for a similar arrangement from your preferred garage, I'm sure they would oblige, especially for someone in your circumstance with an ill wife to consider.

Jim.


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## pneumatician (May 1, 2005)

*Wheel Bolts*

In my previous life (pre-retirement) I was involved with the Aerospace and Motor Vehicle industry, screwing cars and aeroplanes together.
One regular requirement was tooling for wheel nuts/bolts. These are critical fasteners with tight tolerances in plant usually done with a Multi Spindle Machine. In the service industry Impact wrenches should only be used for wheel removal,reassembly must always be finalised with a calibrated torque wrench. Copper slip or thread lubricant should never be used as the underhead and thread friction are a vital component in keeping the wheels in situ. Lubricant leads to over tightening and which could cause bolt/stud failure.

I was involved with companies experiencing bolt/stud failure on heavy vehicles probably in the 80's. Fatalities were caused by stray wheels. The general cause was over tightening resulting in stud failure. Trucks are now fitted with creep indicators.

Just bear in mind Wheel Bolts/Nuts are critical fasteners, failure is life threatening.

See:- http://home.jtan.com/~joe/KIAT/kiat_1.htm an example


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## Phil42 (Apr 4, 2006)

Thanks all.

Perhaps it's appropriate to mention again that the problem in this case was *non-tightening*.:smile2:

Phil


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## vicdicdoc (May 14, 2005)

I always use a torque wrench to set the tightness of my wheel bolts - and on a regular basis over a longish trip . . Belt & braces me !


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## Dill (Jun 3, 2010)

I have just been looking at an old invoice from the garage I use, it says Customer Notes: Please re-check wheel bolts / nuts after 20 miles failure to do this may result in wheels coming loose. I have always thought this was a bit of a disclaimer myself but I always checked them.

Regards

Dill


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## Pudsey_Bear (Sep 25, 2008)

Phil42 said:


> OK, the journey to the garage went very smoothly. It's quite clear that the problem had nothing to do with torque wrenches (of which more later) but was, as we suspected, a failure to do the final tightening on that wheel after the vehicle was back on the ground. I was able to watch as the guy responsible first checked the threads of each bolt on the wheel, one at a time, and then handed it to the boss to check. They were all OK. Then all the bolts on the other wheels were checked for tightness. They were all OK.
> 
> No torque wrench was used. I asked Mike what the torque should be and he told me that they tended not to use torque wrenches on wheels as they knew from experience when a bolt was tight. The wrench the guy used had a very long handle and then it was a case of tightening and then giving one more little turn. Now before you all throw up your hands in horror, I'll deal with Kev's question re vehicle experience. I've driven and owned a large number of different vehicles (mostly cars but including two VW Transporters) for more than 50 years. For most of that time i've done the vast majority of servicing and repairs myself. I have replaced an engine and a couple of gearboxes, worked on brakes, fuel pumps, various kinds of joints etc. I've changed many, many wheels in my time - remember when we were advised to rotate tyres? I have owned a torque wrench (it was needed for some vital bolt or other) but hardly ever used it. None of my wheels ever came loose, never mind fell off. I'm not sure that my garage is particularly unusual and I'd suggest that it would not be as popular as it is, they moved into larger purpose-built premises during my time, if their method of tightening wheel nuts/bolts was inherently unsafe.
> 
> ...


I hope you were not offended by my questioning your abilities, the post had not referred to it/them, so no way for me to know, the main thing is it's back at the garage, but I'm very surprised that there is no damage at all to the threads or the wheels bolt holes and tapered seats.


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## erneboy (Feb 8, 2007)

I think it's unclear whether they were tapered seats Kev, may have been alloys with shouldered bolts. Don't know, Alan.


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## Pudsey_Bear (Sep 25, 2008)

erneboy said:


> I think it's unclear whether they were tapered seats Kev, may have been alloys with shouldered bolts. Don't know, Alan.


True, I've just never seen any wheel nuts or bolts that did not have a taper on them, it helps to centre the wheel holes on the threads, so the wheel is clamped rather than bearing onto the studs and damaging the threads.

I'm not saying there are no wheels without tapers, only that I've not seen any before.


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## erneboy (Feb 8, 2007)

Ava look ere Kev. Some with and some without http://www.mistertee.co.uk/6.html


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## Pudsey_Bear (Sep 25, 2008)

erneboy said:


> Ava look ere Kev. Some with and some without http://www.mistertee.co.uk/6.html


Must be for posh peeps wheels, never had any like them, most of our cars have had alloy wheels, but just std nuts on them with taper.


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## Phil42 (Apr 4, 2006)

Kev_n_Liz said:


> I hope you were not offended by my questioning your abilities, the post had not referred to it/them, so no way for me to know, the main thing is it's back at the garage, but I'm very surprised that there is no damage at all to the threads or the wheels bolt holes and tapered seats.


Not offended at all. I'm confident now that everything is as it should be but I will still be listening out for any unusual noises and also checking the tightness just to be quite sure.


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## Phil42 (Apr 4, 2006)

I came across this article on torque wrenches which may go some way to explaining why some garages don't use them and others may not keep them properly calibrated. Perhaps these issues apply to some drivers who have their own torque wrenches?

This passage is maybe a bit of an eye-opener:

_The reason that there is really no simple answer to the recalibration interval question is that circumstances of use will vary widely and this will have a direct bearing on how long the torque wrench is likely to stay in calibration. Factors such as the frequency of use, setting of the wrench as a percentage of full scale (which leads us onto the second question) and general care taken in use and storage will all have their effect. For example, a helicopter assembly company that I have visited tests their wrenches before every single use due to the degree of safety criticality of the bolted assembly. A typical automotive garage might find this degree of control onerous and unnecessary!

The other important statement made by the standard is that if a torque wrench is subjected to an overload of 25% or more above the nominal maximum, it should then be recalibrated. For many, this might be the ultimate decider on how often your wrenches should be recalibrated. For some, it will be almost every time the wrench is used!_


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