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Stud conversion?

MaxA

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11 Oct 2015
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2,697
Has anyone done a stud conversion?

I'm just about to order some new wheels, and I thought I'd throw some Rennline studs into the basket, to make life easier when it comes time to swap rims (summer-winter) or even just for cleaning...
 
Hello MaxA

I know it's been over 5 years since your original post, but this thread came up in a search, so thought I would post a reply :D

Did you get very far with the stud conversion? Which studs did you go with - the Rennline studs? I haven't heard very good things about them tbh. I know of 1 GT3 owner here who has experienced these studs cracking, and I've read similar experiences on Rennlist. Whether this is down to user error or component quality, no idea...

Reason I'm posting is I have a couple of sets of different studs which I'm yet to try out. The thing stopping me is the inconsistent views I've read with respect to using threadlock - on the internet, but also from speaking with people directly

Some people don't bother, some people say they wouldn't use studs without threadlock. Some people say blue is fine, other people say NEVER use blue, use red, and others say NEVER use red lol. Minefield...

My assessment so far is that the threadlock is there to prevent the studs from backing out from the hub, when you loosen the nuts to remove a wheel. The risk is that the person changing the wheel does not notice this and merrily refits the wheel and nuts without realising the bolts have loosened from the hub. This is what the threadlock is supposed to be for ...

So my current thinking is, if I am prepared to re-torque the studs into the hub EVERY time I change a wheel, then there's no need to use threadlock

It then gets more complex when people also insist that the threadlock is there to stop the studs from loosening due to vibration etc while driving, but if you torque to the manufacturer(s) limits (whatever the stud manufacturer stated NM is for the studs into the hub, and then 160NM for us for the wheel nuts), then there shouldn't be a problem surely... but I'm no engineer and this is only my laymans assessment

So those are my thoughts really, I would be interested to see if any other forum members here have any thoughts

I'm happy to re-torque the studs into the hub on every wheel change as a precaution, so in principle I'm happy to go threadlock-free... but I'm chicken and am yet to fit the studs I've sourced until I've done more research

:typing:
 
Yup, I did the conversion, although from memory, I found (official) Porsche Motorsport studs (the snub-nosed ones) from somewhere.

They went in with thread lock (left to cure for 24 hours) and haven't come out since. I actually had this done at a motorsport shop called AUH up at the Dubai Autodrome (they run all sorts of cars from Radicals to TRD 86s) as I didn't have too many tools with me in Dubai, let alone a garage...

I replaced the nuts with fresh Bilstein nuts last autumn, as they were starting to look and feel a bit tired, and one I suppose got cross threaded as it didn't want to wind on. Silly me.

I also running studs on my R53 MINI, which are a little easier to install as they are the open-ended type you can torque with a hex instead. I've used Loctite 270 for the strength and heat resistance.
 
Just to follow up, and given our experiences with the MINIs at the track - where both studs and wheel nuts have loosened due presumably to heat and vibration - I wouldn't install studs without threadlock. But that's just me.
 
:thumb:

Interesting re the Mini studs working loose

I take it that the studs that came loose were installed with threadlock? Or was no threadlock used?

I have read that threadlock can become a lubricant if the temp rating for that particular threadlock is exceeded

I wonder if that is what happened there, and if you had not used threadlock, would the studs / nuts have still come loose?

The studs fitted by AUH, is that a road car only or is it also used on track? Maybe you've never experienced those studs loosening, because that car's hubs never get hot enough?
 
I use the same threadlock from Loctite ... our MINIs tend to generate some heat under braking at the short tracks, especially when fitted with BBKs/aggressive pads and running 20-30 minute sessions. I've seen guys with shitty pads come in on fire. In short, we have learned to check the torque between sessions. Doesn't seem to happen on the later generation MINIs though for some reason.

I've not had this with the 997, which does get tracked occasionally, as I suspect that all four corners are working more evenly to slow the car. I do carry my torque wrench in the track box and check the torques as well as tyre temps - it's seen action at Dubai Autodrome and Yas Marina in the UAE and at Alastaro, Pesà¤mà¤ki and Kymiring over here.
 
That would be a good comparison to see, a Mini with threadlock vs a Mini running without. After a session see if studs on the one without threadlock are coming loose, or need greater tightening than the ones with the threadlock

One other thing, for the studs that work loose even when threadlock is used, is the old threadlock residue cleaned out of the stud threads and hubs Eg with brake cleaner? Or can the new threadlock just be applied straight on?
 
Roro said:
That would be a good comparison to see, a Mini with threadlock vs a Mini running without. After a session see if studs on the one without threadlock are coming loose, or need greater tightening than the ones with the threadlock

One other thing, for the studs that work loose even when threadlock is used, is the old threadlock residue cleaned out of the stud threads and hubs Eg with brake cleaner? Or can the new threadlock just be applied straight on?

This is getting a bit scientific; we had more problems with loose bolts than loose studs, so all the track rats tend to run studs. It's also easier as we often switch between winter, summer and semi slicks.

When a stud did come loose on the right rear at Knutstorp a couple of years ago, I just cleaned the threads as best I could with a wire brush and added more threadlock to cure in the residual heat over the lunch break. I didn't take any Brakleen to that trackday. As far as I recall, it's still there.

The studs on the 997 haven't moved at all.

There is also a thread on a 997 owners thread on FB, but I think the questions revolve around lube on bolts which I definitely do not use.
 
Lube on bolts?! Why on earth would anyone do that ... :eek:

Thanks for sharing your experiences, it makes for a very interesting read! I'm surprised loose bolts are more of an issue than loose studs, but then again, this is the reason many (like myself) take a torque wrench on trackdays and are in the habit of torquing up periodically
:thumb:

I guess I just need to decide which threadlock then

One more silly question I just thought of :)

If you use threadlock, then how do you check stud torque when you change over your wheels?

My thinking is if I re-torque the studs into the hubs to be sure they're not loose, then I'm breaking the bond created by the threadlock/Loctite?

Maybe a visual check with a marker pen is enough, mark each stud so it's easier to see any movement after removing a wheel?
 
I don't check stud torque when I change wheels, they're Loctited in. It's pretty obvious if they've moved as they're loose ... and you'll know the moment you fit the socket. Of course, this only happened once (on the Mini, maybe too little Loctite), unlike wheel bolts which frequently loosen in extremis. I suppose it's because studs need so little torque on installation in the first place.
 

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