torque setting for wheel nuts
- Thread starter Alpine
- Start date
duncan_956
New member
Excuse my mechanical ignorance, but how important is it to have your wheel nuts set to the correct torque setting?
I've read a few posts about torque settings and started me thinking - I've always gone down the road of putting my substantial weight behind it and doing them as tight as possible...
My car is a mark 4 golf gti, obviously a bit different from an S2, so what would the impact be on the car if not followed?
I've read a few posts about torque settings and started me thinking - I've always gone down the road of putting my substantial weight behind it and doing them as tight as possible...
My car is a mark 4 golf gti, obviously a bit different from an S2, so what would the impact be on the car if not followed?
Diver944
Active member
It's certainly important with a 944 because the wheel nuts are a very light, very soft alloy and if you overtighten them they can strip the thread and eventually come loose [
] Let's not forget they are probably 20 years old if still original.
If you undertighten them then once again they can work loose []
Either situation is not one I want to be in anytime soon []
] Let's not forget they are probably 20 years old if still original.If you undertighten them then once again they can work loose [
]Either situation is not one I want to be in anytime soon [
]duncan_956
New member
Thanks for the info, Paul.
Can't imagine that VW nuts would be made from the same soft alloy and they're not 20 years old, the thing that got me thinking was I've recently had all 4 tyres changed while in for a service at an independent garage. Occasionally while driving on the motorway the car will act as if it's windy (very, very slight movement) and I've put ithis down to either a different make of tyre from what I've been used to, gone from Goodyear to Dunlop, or a bit of tramlining. I don't feel this when driving down normal A/B roads.
......runs off to check wheel nuts...
How do you measure the torque settings? What type of tool would you use?
Its very important to have them done up! I found this out after I had my wheels balanced at a garage, they took the wheels off, balanced them put them back on, tightend up the drivers side and... didnt tighten up the other. needless to say the slight vibration that i had on the wat to the garage was slightly forse 100m after I left the garage. I pulled this face at them -->[] they were very sorry! Just as well i didnt give it some beans when I left or I may have been overtaken by a round black rolling missile!
] they were very sorry! Just as well i didnt give it some beans when I left or I may have been overtaken by a round black rolling missile!Wigeon Incognito
New member
I've had that!
I was driving a flat bed truck through a zoo when it was closed so decided to see how fast I could go down the central path. I got up to about 50mph, went through a big dip on a curve in the path, heard a very loud clang, and saw my wheel overtaking me heading towards the gorilla lake!
Luckily I had no weight in the back so it stayed on three wheels.
Annoyingly I could blame nobody but myself - I'd changed the wheele earlier in the week but remembered I was called to an escape when I was putting the wheel back on so had only tightened the nuts finger tight.
Neil Haughey
New member
Also very very important to insure the stud threads have a good coating of clean optimoly grease. I found that after greasing the studs my nuts took a lot more turns of the torque wrench to finally reach 95 lb (the workshop manual gives the advice about the correct grease can't remember exactly which one, ISTR its Castrol Optimoly). I interpret this as saying that without the grease the nuts bind onto the stud rather then putting the correct amount of tension in the studs.
Hate to be a stickler Neil - but technically you shouldn't be greasing any threads, as it will give a false impression of torque loading to the mating faces. I won't bore you with the details, but will just say threads should be clean, and greased after the tightening operation to prevent them from corroding etc.
It's still something 99% of us do though . . . . . . . [8D]
Mike
It's still something 99% of us do though . . . . . . . [8D]
Mike
Tam Lin
New member
Technically based on what, might I ask?
The Optimoly recommendation is in the Porsche workshop manual. In fact they consider it essential. I know Porsche don't always get it right, but given the almost unique light aluminium nut/MgAl wheel/steel bolt combination, I doubt many other people will have done as much testing as them on this particular fitment.
The Optimoly recommendation is in the Porsche workshop manual. In fact they consider it essential. I know Porsche don't always get it right, but given the almost unique light aluminium nut/MgAl wheel/steel bolt combination, I doubt many other people will have done as much testing as them on this particular fitment.
Hilux
New member
It's certainly important with a 944 because the wheel nuts are a very light, very soft alloy and if you overtighten them they can strip the thread and eventually come loose [
If they have lost their coating and are whitish in colour they should be changed.
I would have thought that he threads should always be totally clean for the torque readings to be correct. Lubrication can create a slip plane and change friction levels between surfaces however some bolts like con rod stretch or main bearing bolts require oiling if the manufacturer specs it
Also do NOT let a tyre centre (or yourself) use impact wrenches on alloy nuts, if you have then change them for they are brittle and the impact gun can create stress fractures.
From FWSM:
Regarding torque with or without an Optimoly lubricant:
a) If I torque the wheel nuts to 130Nm without a lubricant (with clean threads), the relative friction between the mating surfaces of the stud and the nut result in a torque of at or around 130Nm when the wrench 'clicks' at 130Nm.
b) If the threads on the studs are lubricated and then the nuts are torqued to 130Nm they are likely to travel very slightly further on the threads due to the lubricating properties of the Optimoly as there is less friction between the mating surfaces of the thread and nut. However, when the torque wrench 'clicks', the resulting torque setting is still at or around 130Nm.
Whichever way you look at it, I am still tightening the nuts to the same torque setting relative to the studs.
Only with option (b), the nuts will be less likely to seize onto the studs when I need to remove the wheels due to the anti-seize properties of the lubricant.
a) If I torque the wheel nuts to 130Nm without a lubricant (with clean threads), the relative friction between the mating surfaces of the stud and the nut result in a torque of at or around 130Nm when the wrench 'clicks' at 130Nm.
b) If the threads on the studs are lubricated and then the nuts are torqued to 130Nm they are likely to travel very slightly further on the threads due to the lubricating properties of the Optimoly as there is less friction between the mating surfaces of the thread and nut. However, when the torque wrench 'clicks', the resulting torque setting is still at or around 130Nm.
Whichever way you look at it, I am still tightening the nuts to the same torque setting relative to the studs.
Only with option (b), the nuts will be less likely to seize onto the studs when I need to remove the wheels due to the anti-seize properties of the lubricant.
sawood12
New member
Well i'd say that if you are not lubricating the threads and achieving the same torque over less distance then the threads are binding on debris generated from tightening the nuts so you probably are not properly torquing your nuts in terms of the tensile loading in the stud and nut. I've always used a small amount of copperslip on wheel studs and nuts not only to ease removal but also to ensure proper torquing.
Another factor to consider here are that because you have alloy nuts on steel studs you will be getting an electrolytic cell set up as you do when dissimilar metals come into contact with eachother. This promotes corrosion and increases the liklihood of your nuts getting siezed on if you don't remove them regularly.
Another factor to consider here are that because you have alloy nuts on steel studs you will be getting an electrolytic cell set up as you do when dissimilar metals come into contact with eachother. This promotes corrosion and increases the liklihood of your nuts getting siezed on if you don't remove them regularly.
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