Snapped wheel stud

[GMB]

On refitting a rear wheel the garage had to phone me to give me the surprising news that one of the wheel studs snapped.

It snapped at very low torque and all the signs indicate that some "wheel fitter" in the past has stretched it and severely weakened the stud. The mechanic who had the "accident" told me it just pulled away like cheese with very little effort  :-)

This can be seen in the picture - the narrowing near the base. Cost of replacing all five studs ( just to be sure ) was £30. My garage felt a bit awkward, even though they are very professional and always use the correct torque and wrench. so no charge for labour. I will be very careful where I get my tyres changed in future.

Our excellent local Lexus dealer told me that this is rare but if it happened while at their garage they would just replace the stud at no cost.

This is a first for me and the garage, a search shows that this is a fairly common issue especially Toyota and Lexus apparently. Take care.

Anyone else had this?

 

[Linas.P]

It is not rare at all and I had at least dozen of them replaced over the time. Actually, it is very simple to get them stretched past the rated torque and it happens pretty much every time I take my car anywhere to get tyres/wheels changed. For example if there is any grease or even moisture on the nut the torque spec will be wrong and every shop I have seen uses air-guns which way way over toques the nuts... even Lexus dealers do that. Most of the time I specifically ask to not over torque wheel nuts and use proper torque wrench instead, but most of "mechanics" in tyre shops don't even know how torque wrench looks, never mind knowing how to use one.

In theory if nuts are torqued to correct torque, then one should be able to easily undo wheel nut with tiny wrench which is included the tools kit, likewise the length of that wrench is specifically calculated to be right for average human being to be able to torque the nut to right spec using reasonable amount of force. If you ever tried undoing wheel nut with standard wrench after visiting the tyre shop, you would know that is nearly impossible to do, because nuts are always over torqued. As result over-time they weaken and eventually snap. 

Usually when I get car from service I take impact gun (that is the safest way of removing over torqued nut) and if that doesn't work then 930mm breaker bar (this is the easiest way to snap the stud). I undo them all, clean the nuts and studs to make sure there are no grease or dirt and then torque them properly with torque wrench to 76ft/lbs/103Nm/912in/lbs. Every 2nd or 3rd time this results in at least one of the studs snapping when I am trying to undo them, but I reckon it is better it happens to me when changing the wheels rather than when I am traveling at 70MPH+ on motorway.

Replacing all 5 studs was unwarranted, but I guess now you have complete peace of mind. It seems you have good relation with the shop you use, so I guess £30 for studs and no charge for replacement was fair deal, although replacing studs takes literally 2min - so 10min job for 5. If it ever happens to me that stud snaps in the shop (and so far it only happened once) then I always insist they cover the replacement of stud they broke. 

[cidersteve]

pretty rare i would say , have had numerous cars over the past 40 odd years and never happened to me and being in the engineering trade never heard one of my fellow engineers talk about this , also very sensible to get all of them changed.

[PRT68]

Yes many years ago when I had a Mercedes 190e. Went to check my front pads, and three sheared. Daren't drive it, so called a mobile mechanic. He brought along 10 new studs with him. In the end, 6 sheared, because he tried the other side as well.

Both tyres were changed 9 months previously, so obviously nuts overtightened.

Would not have been able to prove the tyre fitters did it, so didn't bother going back, and have never used them again. 

brake pads were OK, but would have been stuck if I punctured on the road side.

[Linas.P]

Must be just rough area I am living in then (London)... perhaps mechanics are less stressed and rush everything less in countryside.  

[Shada]

Quite common on Toyota lexus, I replace many of them at work. Over tightening is the main cause but over tighten them cold and they have no chance. 

Seen one tyre centre snap one on a 3 month old avensis while repairing a puncture, and denay it was their fault. 

[NemesisUK]

Is it better the stub snaps than deforms or perhaps better than being overly robust and distorting the alloy wheel?

Obviously none of this matters if they are torqued correctly but ...

[Linas.P]

4 minutes ago, Shada said:

Seen one tyre centre snap one on a 3 month old avensis while repairing a puncture, and denay it was their fault. 

They always try that, but anything that broke at their premises and that was not broken before it entered their premises is their fault (legally). Obviously within reason, it would difficult to blame them for blowing the engine on which they didn't even work, but if their job was undoing wheel nut and they broke the stud, then it is definitely their fault. I think it is not the cost of the parts, but rather overall time sourcing the right part, getting it delivered and occupying shop space with extra car for a day, which they are trying to avoid.  

My worst example was the insurance bodyshop which was repairing my car after accident, part of repair included refurbishing wheels and replacing tyres... when handling over car back to me the guy told me "one stud broke, so we put some hermetic on the nut and put it in place for now"... as you can imagine this made my face green, then purple for the moment, but I manage to composed myself after like 10 seconds and asked politely:

"so you are saying you broke the stud and instead of replacing £5.74+VAT part (on overall £2800 repair), you have glued the nut using hermetic glue, which means this glue will have to be scraped now from newly refurbished £500 worth wheel and scraped from the nut and then I have to fix the broken stud myself - that sounded like right thing to do for you?! .... I appreciate the honesty, but what you going to do now - get the wheel cleaned or refurbish it again if needed, order new nut, new stud, replace them and then comeback, otherwise I am not signing-off repair".

[Shada]

5 hours ago, NemesisUK said:

Is it better the stub snaps than deforms or perhaps better than being overly robust and distorting the alloy wheel?

Obviously none of this matters if they are torqued correctly but ...

Seen many of wheels over tightend that they have broken wheel bars trying to loosen them. None distorted the wheel, on top of that the Toyota lexus nuts have a nice big flat washer on them so the wheels will be safe nomatter how tight. The studs are just a little softer than you'd like. 

[Shada]

5 hours ago, Linas.P said:

They always try that, but anything that broke at their premises and that was not broken before it entered their premises is their fault (legally). Obviously within reason, it would difficult to blame them for blowing the engine on which they didn't even work, but if their job was undoing wheel nut and they broke the stud, then it is definitely their fault. I think it is not the cost of the parts, but rather overall time sourcing the right part, getting it delivered and occupying shop space with extra car for a day, which they are trying to avoid.  

My worst example was the insurance bodyshop which was repairing my car after accident, part of repair included refurbishing wheels and replacing tyres... when handling over car back to me the guy told me "one stud broke, so we put some hermetic on the nut and put it in place for now"... as you can imagine this made my face green, then purple for the moment, but I manage to composed myself after like 10 seconds and asked politely:

"so you are saying you broke the stud and instead of replacing £5.74+VAT part (on overall £2800 repair), you have glued the nut using hermetic glue, which means this glue will have to be scraped now from newly refurbished £500 worth wheel and scraped from the nut and then I have to fix the broken stud myself - that sounded like right thing to do for you?! .... I appreciate the honesty, but what you going to do now - get the wheel cleaned or refurbish it again if needed, order new nut, new stud, replace them and then comeback, otherwise I am not signing-off repair".

Shocking what some will do, a photograph sent to vosa would have been interesting 

[PPD]

I've had Lexus wheel studs snap, once whilst changing from summer to winter wheels [grrr...]. Only thing to be said is breakdown guys are comfortable with driving the car with only 4 studs to a garage, and the replacement is straightforward. This is unlike current Ford Fiesta's, which require the whole assembly to be replaced!!

[Linas.P]

Yes the studs on IS250 are very strong, they are commonly used on all Toyotas from Landcruisers to 1000HP Supras (not BMW Zupra - those have bolts as most BMWs). Don't quote me on this, but when I was looking for "upgrade" I have read that only 2 studs are enough to keep the wheel on, and the rest is just contingency. So it is indeed safe to drive on 4 studs, but I know the feeling - despite logic and specs indicating that even 2 studs should be enough to hold the wheel in place it still feels like the wheel will fly off at any moment. And other thing - there are no upgrade for these studs, these are highest grade studs for their size.