Wheel Studs, rattle guns and the nuts that use them

[snowman]

Here is a tale of caution for all of you Triton owners (I dare say any car to be honest).

I had had to order a FULL SET (24 total) of new wheel studs as I have had two break off recently. These cost $125 + labour to fit. A reasonably significant maintenance cost on a vehicle less than 2 years old. However, how can you take the risk of losing a wheel with multiple stud failures around a fast sweeping corner with your whole family in the car.......

I have no hard evidence but a VERY GOOD IDEA of how this happened.... short story is NEVER let ANYBODY do up your wheel nuts with a rattle gun. I am sure that many or even most rattle guns are set and used competently, however some are not and it only takes one friggin idiot.

The two breakages have occurred since my 30,000km service and although I think it was this service that was the 'straw that broke the camels back' I do NOT blame Mitsubishi for this. In fact I blame the massively uneducated tyre fitter who put on my new mud tyres at 40klm (yes 40 one more than 39 - not 40,000). I won’t name them only because it is impossible to prove but this is my reasoning…. (PM me if you live near Blacktown in Sydney)

Almost two years ago (March 09) I had new tyres placed on to replace the standards almost at delivery (one of my biggest regrets now for a whole host of reasons). I recalled the other day (actually my wife reminded me to her credit) that when I brought the car home with my new mud tyres I tried swapping an ML wheel with one of my old MK wheels (to see if they would swap - they don't) and I needed a long bar and all my 110kgs to undo my ML nuts. Once I went around and loosened them all (I am quite paranoid about this item as you cannot undo them on the side of the road when they are too tight) I did not think much more about it. However in hind sight this massively over-tightened moment stretched the studs or certainly weakened them.

In the subsequent 30,000 kilometres they have had numerous services, tyre swaps, wheels off for suspension, brakes etc. but on all these occasions I have not had to swing off any nuts to undo them.

On the occasion the first one broke off I was doing them up with my very short wheel brace and the second more recently (and a different wheel) when a mechanic was doing it up – he advised that he did not feel it was them and based on the fact that it had only just happened to me a few weeks prior I felt that was reasonable. The broken studs have been ‘stretched’ and you can see how the thread pitch has elongated between the nut and the hub.

So I dare say that the Mits 30,000klm service did go a little hard on the ‘rattling’ and probably pushed the already weakened studs over the edge I would have a hard time getting this past as they have no history of this on other Tritons.
I am a reasonable bloke and although they have replaced the first two broken studs they would not do any more, which I will accept.
Ultimately I have had to make a risk assessment and although it may be unlikely to lose a whole wheel simultaneously it is certainly a hazard outcome I am not willing to accept.
It would seem that once they are done up too tight the damage is done – even if it does not appear to break immediately.

One item which perplexed me was Mitsubishi saying they could not warrant it because I had taken my wheels off………WTF.

[Diddy]

thats not good to hear snowy a lot of tyre shops use the torque extentions that fit the end of the rattle guns they come in different colours. so that it doesnt over tighten and strip the wheel studs.Each coloured bar has different torque figure and shaft size and u can fit wat ever size socket on the end of it as long as it was 1/2" drive. but there are a lot of workshops n tyre service centres that still use the old school way of just rattle it up until it wont go no more

[ag9111]

Funny you should post this up Snowman as I have just ordered 6 aftermarket wheel studs for the drivers side front. Had a tyre repair done aand now two of the nuts have galled onto the thread due to some gorilla doing them up to tight. Still have to order 6 OEM wheel nuts so if anybody has a set PM me.
No wonder I do all my own maintenance on the family cars

[Brett05]

That's something everyone should be aware of, but sadly enough we trust the tyre guys to do the wright thing.

When I bought my truck, the dealer had fitted the factory mags to replace the steel poverty pak rims. A few weeks later I had the MTZ's fitted by Tyre Power and the owner pointed out that the nuts were off the steel rims and very very dangerous to be running around like that. Left Tyre Power and went back to the dealers. Went to the used car (truck) manager and told him, he sold me a truck that should never have passed a road worthy inspection. To their credit, he walked out had a look them and agreed. Then arranged for me to call into Goodyear T/C and get the correct ones fitted. I have my wheels rotated at tyre power, where I got the tyres from and they use a battery powered rattle gun to speed the nuts on, then use a torque wrench to tighten them up.

Something to remember, the current Toyota Camrey has the same nut used on the OEM mags for the Triton

[snowman]

thats not good to hear snowy a lot of tyre shops use the torque extentions that fit the end of the rattle guns they come in different colours.each coloured torque bar represents a wheel nut size so that it doesnt over tighten and strip the wheel studs but there are a lot of workshops n tyre service centres that still use the old school way of just rattle it up until it wont go no more

how does that work?

like can i buy a suitable one and say to whomever is taking the wheels on and off - use this or else!!!!?

[Blue]

I instruct the dealership to service, road test then put her on the hoist for wheel rotation/brake inspection, I put the wheels on and torque them manually when I pick her up... They were very hesitant at first but after explaining my woes with the MK and 'a certain' Mitsu doing them up so tight I needed 3 foot of water pipe and my full 125kg AND had to bounce on the pipe to loosen them, resulting in 4 snapped studs on one hub, they agreed to my terms...

[Diddy]

yes that is wat u say. when i was a young fella 1 of my 1st jobs was a tyre fitter and if we didnt use these torque bars it was a instant dismissal offence cos it was just way to common that people would do damage with rattle guns

[Blue]

thats not good to hear snowy a lot of tyre shops use the torque extentions that fit the end of the rattle guns they come in different colours.each coloured torque bar represents a wheel nut size so that it doesnt over tighten and strip the wheel studs but there are a lot of workshops n tyre service centres that still use the old school way of just rattle it up until it wont go no more

How does this work, same size nuts on both cars and completely different torque settings...?!?!?!?

[Diddy]

Each coloured bar has different torque figure and u can fit wat ever size socket on the end of it as long as it was 1/2" drive. My bad in my first reply it has been 13yrs since I done that job


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[gregned]

when the torque is reached they just flex minutely and when the rattle gun has finished the impact cycle the shaft springs back ready to twist again happens about 8 to 10 times per second thicker shafts apply more torque naturally.

[borngeek]

It is the rattle gun causing issue without doubt... Those torque bars should be law..

I recall helping wrenching off Daryn's damaged tyre and man were they tight... (the wheel nuts were tight ok)...
Took all 115KG of me to budge them.

I agree with the mantra if more than one dies replace the lot.. You cant really play russian roulette when it comes down to it...

[Diddy]

thats not good to hear snowy a lot of tyre shops use the torque extentions that fit the end of the rattle guns they come in different colours. so that it doesnt over tighten and strip the wheel studs.Each coloured bar has different torque figure and shaft size and u can fit wat ever size socket on the end of it as long as it was 1/2" drive. but there are a lot of workshops n tyre service centres that still use the old school way of just rattle it up until it wont go no more

these torque bar sets arent cheap ( $450 ) but if u had ya own workshop they make for cheap insurance

[slipn]

All workshops should use Torque bars.. actually if they don't then they are not a real workshop and have no idea what they are doing. I have worked at a few tyre shops in my life both in Australia and overseas and all of them used torque bars.

One of the main reasons for using them is obviously too stop any damage and because using a gun without one will make it almost impossible for someone to get their wheel off without air tools.

Just imagine a little grandma with a flat on the side of the road trying to undo her wheel nuts when they have been wound up with a rattle gun!!

if you see anyone in a workshop tightening your wheel nuts without a torque bar run up to them and smack them in the head and never take your vehicle back, its dangerous and there should be laws made about using proper equipment.

[MitsiGuy]

I have seen this with some wheels also from vehicles that come into the dealer I work at. More so the ones that we havent seen before. At the dealer I'm at we do them up by rattle gun using the torque bars. and then for 2nd measure we go around and use a torque wrench to make sure they are ok.

The torque bars can also be bought individually also. The one I use is the red one and that torques upto 120Nm.

[NowForThe5th]

Just for the record, the correct torque is 128Nm for alloy wheels, 147Nm for steel.

[Homer]

Hey 5th just checking that those are the correct tensions as I'm going to order a couple of torque bars?

Not doubting you..I just can't find it anywhere else and they seem to have quite a few different torques for different vehicles??
Only reason for the question is on the alloys the bolt face and washer bolts up flat to the the wheel with a fair bit of surface area and on the steelies it is just a little taper on taper.

I could see the steel rim flexing where the flange was as they're not hubcentric..

[Longranger1]

I use these torque limiter extensions myself. The local BJ TMart doesn't appear to use them at all

If you are using a rattle gun on wheel nuts then they should be mandatory - we all know the results of overtightening. It seems that some places have people that could not give a sh!t about your safety or your vehicle. One of my pet peeves is the overtightening of wheel nuts with rattle guns.

I use a darkish blue extension which is rated at 110Nm or 80ft/lbs. I do treat the threads with heavy duty Lanotec but not the nut faces. The torque limiter extensions do seem to work though when the wheelnut is tested with a calibrated torque wrench. I also treat the hub faces with lanotec as well but dry it off so there is only a trace left (stops the rust between the alloy and the hub).

A little less torque than what 5th says (which is correct) but lubed threads make up for it. So far I haven't had any loosening issues.

Edit: There is a warning about applying oil to the threads in the owner's manual causing overtightening.
The torque values listed are for dry threads: Steel wheels 137 to 157Nm, Alloy wheels 118 to 137NM.

[snowman]

i just had new tyres placed on my MK triton and after ordering them i asked if they could use the torque bars. they dont even have any.

i insisted on 'hand tightening' at every phone conversation and drop in. then when i picked it up i got out my brace and checked every wheel before paying for them. they thought i was a bit mad.....

they were OK. but bloody hell it just proves a point. any idiot can open a tyre shop and not have any regard for thse issues.

[Quinny]

A little less torque than what 5th says (which is correct) but lubed threads make up for it. So far I haven't had any loosening issues.

Edit: There is a warning about applying oil to the threads in the owner's manual causing overtightening.
The torque values listed are for dry threads: Steel wheels 137 to 157Nm, Alloy wheels 118 to 137NM.

So I just had new tyres fitted and watched with pain as the air spanner was used to tighten the wheel nuts

They then did use a torque wrench on every wheel nut - but ... if they were over tightened beyond the 118 to 137NM as recommended above ... wouldn't the torque wrench "click" as soon as they lent on it ? Not sure how those things work but I thought you would tension up to the desired value ... It wouldn't know if it was over-tensioned ...

[snowman]

So I just had new tyres fitted and watched with pain as the air spanner was used to tighten the wheel nuts

They then did use a torque wrench on every wheel nut - but ... if they were over tightened beyond the 118 to 137NM as recommended above ... wouldn't the torque wrench "click" as soon as they lent on it ? Not sure how those things work but I thought you would tension up to the desired value ... It wouldn't know if it was over-tensioned ...

i believe the thickness of the torque bar allows it to 'twist' at a certain torque (der sorry) when on the impact wrench. obviously the air gun provides turning pulses and then in between the pulses the torque bar goes back to its normal state and it happens all over again once the nut resists beyond that torque bar maximum twisting strength. bloody hell i have confused myself.

ok....in other words the bar distorts and winds up once the nut gets to a certain pre-determined tightness. however it only works with air or impact wrenches in small pulses. you can't use it by hand and keep turning it around and around.

so if they have gone beyond the bar torque before they put it on then it is useless.

[Longranger1]

A little less torque than what 5th says (which is correct) but lubed threads make up for it. So far I haven't had any loosening issues.

Edit: There is a warning about applying oil to the threads in the owner's manual causing overtightening.
The torque values listed are for dry threads: Steel wheels 137 to 157Nm, Alloy wheels 118 to 137NM.

So I just had new tyres fitted and watched with pain as the air spanner was used to tighten the wheel nuts

They then did use a torque wrench on every wheel nut - but ... if they were over tightened beyond the 118 to 137NM as recommended above ... wouldn't the torque wrench "click" as soon as they lent on it ? Not sure how those things work but I thought you would tension up to the desired value ... It wouldn't know if it was over-tensioned ...

That's right. Used that way the torque wrench would click showing that the torque met or exceeded the proper value. Numpties
To do it properly you would use a torque limiter extension of a value a reasonably lower value then finish off with a torque wrench.
Edit: Snowies right too, torque limiters only work with rattle guns.

[Quinny]

Sorry Snowie - I may have misled everyone... They didn't use the pretty coloured ones on the impact wrench...

They used a traditional torque bar after they were done with the impact wrench ...

But I think you know what I mean when you say: "so if they have gone beyond the bar torque before they put it on then it is useless."



Apologies

[snowman]

no you didn't. my misread. trust me when i tell you i have drunk WAAAAY too much coffee today.

same deal though. closing the gate once the horse has bolted. hope your nuts aren't too tight.

been there, done that.

[Quinny]

no you didn't. my misread. trust me when i tell you i have drunk WAAAAY too much coffee today.

same deal though. closing the gate once the horse has bolted. hope your nuts aren't too tight.

been there, done that.

Thanks for your concern


I once had a Magna with a flat tyre - and for love or money - I couldn't get the wheel nuts off... Had to call NRMA

[Longranger1]

no you didn't. my misread. trust me when i tell you i have drunk WAAAAY too much coffee today.

same deal though. closing the gate once the horse has bolted. hope your nuts aren't too tight.

been there, done that.

Thanks for your concern


I once had a Magna with a flat tyre - and for love or money - I couldn't get the wheel nuts off... Had to call NRMA

Sounds like a Nureyev type of problem .