question on studs.

[roastbeef]

I see a lot of people torquing their lug nuts after seemingly every session. I bet it has something to do with the studs snapping. You're basically snugging it up when it's the hottest and most expanded it's going to get, then it cools and contracts causing more stress.

[1MOREMOD]

+1, do a mid day check after lunch when cool

[pbonsalb]

It’s the tire shops using impacts that I don’t trust. I try to bring them the wheels instead of the car whenever possible. 2 of my 3 bnwd have studs.

[HerbNRacer]

Originally Posted by pbonsalb

It’s the tire shops using impacts that I don’t trust. I try to bring them the wheels instead of the car whenever possible. 2 of my 3 bnwd have studs.

Never trust the tire shops, they have broken countless studs on my cars from using impacts to install the wheels. I too bring them the wheels alone. Never had a broken stud sense.

Also +1 for roastbeef!

P.S. Anti-seize is your friend!!

[pbonsalb]

I use anti seize also, but the tire shops always say not to. It’s fine as long as you torque to the proper spec given the anti seize and keep the anti seize off the cone face of the nut.

[slicer]

Originally Posted by pbonsalb

I use anti seize also, but the tire shops always say not to. It’s fine as long as you torque to the proper spec given the anti seize and keep the anti seize off the cone face of the nut.

How can you torque to the correct spec when anti-sieze completely alters the torque reading? Lug torque specs are based on dry lugs. You are adding lubrication, thus making any given torque spec actually tighter.

[pbonsalb]

You are correct that you would have to be comfortable with a certain torque using anti seize. It may well differ from dry studs. It’s not 30 weight oil but it will likely have some effect over even new clean and dry threads. I am sure the difference could be determined, but I have not bothered—I use 88 lbs and have been using it for years without issue on antisense treated studs.

[slicer]

Originally Posted by pbonsalb

You are correct that you would have to be comfortable with a certain torque using anti seize. It may well differ from dry studs. It’s not 30 weight oil but it will likely have some effect over even new clean and dry threads. I am sure the difference could be determined, but I have not bothered—I use 88 lbs and have been using it for years without issue on antisense treated studs.

What motivated you to use anti-seize in the first place? Were you having issues with corrosion? Is the car driven in the winter and exposed to road salt and/or de-Icing chemicals? If so, I can see the desire to prevent corrosion / seizing. If not, then there is no point in going outside of the recommended 'dry' approach. I have never had any corrosion issues but I live in a mild climate. When I lived in the midwest I used regular lugs which are less exposed to the elements than studs. Never had any corrosion issues with lugs in MN winters.

[pbonsalb]

I live in NH and drive year round. Rust and corrosion are a losing battle. I have to kick repeatedly to free unbolted wheels from hubs. Rotor hold down bolts strip. Rotors must be sledgehammered to get off the hubs. If I don’t use antiseize on stud threads, I risk undoing the red loctited studs from the hubs when removing the stud nut. Plus antiseize does not hurt anything if you know what you are doing. Your engine is held together with lubricated bolts.

[slicer]

Originally Posted by pbonsalb

I live in NH and drive year round. Rust and corrosion are a losing battle. I have to kick repeatedly to free unbolted wheels from hubs. Rotor hold down bolts strip. Rotors must be sledgehammered to get off the hubs. If I donÂ’t use antiseize on stud threads, I risk undoing the red loctited studs from the hubs when removing the stud nut. Plus antiseize does not hurt anything if you know what you are doing. Your engine is held together with lubricated bolts.

Makes sense in your climate. I don't miss dealing with that but it's not seeming so bad when I there's a massive wild fire heading my direction

[inTgr8r]

M2C

I understand completely the over torque theory about using anti-seize on the studs, and agree with this.
What you don't often see mentioned is the opposing problem of dirty or rusty studs/bolts.
Studs when new are nice & smooth & torque up very smoothly. (some are coated)

After re&re a few times introduces dust & dirt ....& eventually light iron oxide.
Actual wheel nut torque will now be less than torque wrench setting!!

FWIW my procedure is to use a (very) little amount of anti seize on a fiber brush to clean the threads.
Then I wipe it off with a rag, getting all the way down into the thread.
IMO this is a happy medium between the two issues.

The main thing however is replace them regularly & use the high quality 12.9 hardened studs that vendors such as Turner carry.
I've seen far too many of the bargain studs fail.

[pbonsalb]

I wonder whether 10.9 is better because it is not as brittle as 12.9. The clamping force here is not huge for each bolt -- I don't think that is what snaps them.

[inTgr8r]

Originally Posted by pbonsalb

I wonder whether 10.9 is better because it is not as brittle as 12.9. The clamping force here is not huge for each bolt -- I don't think that is what snaps them.

I dont think 12.9 hardness rating means that its more brittle.

Sorry... its been a while since I looked at specs.
Turner doesn't actually use the 12.9 rating designation.
theirs are "heat-treated 190,000 psi chrome moly steel, shot-peened"

& R.Eng. rates theirs as; "PRO studs exceeded Grade 12.9 yield strength by an average of 14.6% and tensile strength by 10.6%"
R.Eng has some good info on studs here.....

Another interesting product from R.Eng is a kit including jig to convert our M12 studs to M14. (30% stronger)


The other thing to look for are roll formed threads rather than die cut.
Roll formed are much smoother and don't stress the stud during fabrication.

[pbonsalb]

Everything I have read says that 12.9 is more brittle than 10.9, but I am not an engineer. The M14 would be good. The newer cars are M14.

[M3 Number 86]

Keep it simple. Studs are always prone to break. Just have a stud stripper and extra studs handy in the tool box. I've been fucked before though as one of the studs decided to break right at the hub lol

This is what worked for me.

All stud companies recommend a 75mm stud if you use up to a 10mm spacer (if I recall correctly). I was using a 5mm spacer with mine but the lug nut seemed a little too close to flush. So on one end of the stud you have a lug nut and on the other end you have it threaded into the hub. It's easier to break a pencil holding both ends. So I upgraded to an 85/88 stud size. Now the lug nut sits further inwards. Harder to break the pencil now.

My engineering degree is from YouTube so I knew this was the problem. but haven't broken a stud since (same brand). After December I will replace regardless since it's been a year.

The stupidity doesn't stop here though. The stupidest thing is that some people would actually buy these used studs in the FS section! I'll keep them as spares though.

[PrimeBMW]

"today I slapped on some 10mm spacers because of nt01 rubbing on kw cs perch (weird just driver side rubs on spring) before moving to shorter and stiffer springs.

I see all 75mm kits mention that they can accomodate up to 10mm spacer but when I torque the nut down you can't see any thread leftover.

should I be moving up to 90mm studs? may do it just to be safe but wondering on your guys' experience.

thanks!

(I have many stupid questions posted and thanks for all the help. I'm just the driver - I need a pit crew for car technical stuff lol)[/QUOTE]"

Just get rid of the KW and buy MCS and your issue goes away

[Fitzpadj]

Keep Dry Graphite around.

Use a thread chaser and then spray a bit of dry graphite and lightly towel off. Much better for keeping a "dry" torque rating and keeps corrosion at bay.

[M3 Number 86]

Originally Posted by PrimeBMW

"today I slapped on some 10mm spacers because of nt01 rubbing on kw cs perch (weird just driver side rubs on spring) before moving to shorter and stiffer springs.

I see all 75mm kits mention that they can accomodate up to 10mm spacer but when I torque the nut down you can't see any thread leftover.

should I be moving up to 90mm studs? may do it just to be safe but wondering on your guys' experience.

thanks!

(I have many stupid questions posted and thanks for all the help. I'm just the driver - I need a pit crew for car technical stuff lol)

"

Just get rid of the KW and buy MCS and your issue goes away [/QUOTE]
I know. Lol. This thread was from a while ago. I've taken out the helpers and they're fine.


Still want mcs though. But I'm doing ok with inferior parts. My team is the Honda Mclaren of m3post