LVDell

I am hypervigilant about these things. I make sure the wheels are on straight. I wiggle the wheel to make sure it is seated. I hand tighten to the wheel face. I torque down in the opposing nut fashion. This is why I am baffled.

Rob S

Hmm. Actually, I once met a woman who would beg to differ with you.

AllanJ

My studs are fine (AFAIK), but I just found out my torque wrench is pooched and have over-torqued them a couple times. So this winter I might change the studs for safety. Already bought a new torque wrench.

TurboCup87

moi aussi

KOAN

Mir Auch! I'm with you, Andy. With screw in studs, there are 2x the number of places where the threads can come loose, for whatever reason. And if either comes loose, the studs are at risk for fracture. Until I understand why these failures are occurring, I'm going back to bolts.

mooty

i use the same stud as your race car on all my 5 lugs p cars, street or traq.
i must have 50k miles +... on variety of cars with that set up.
on track, i tq them every time i come off track once the wheels have a bit of time to cool down. the nuts are usually still tight. when i have wheels off, i always hand turn each studs to just make sure they are tight, and they were always tight to the hand. they were put on with red locktite. no other special things done to it. i dont use tq bar to loosen them. i use impact gun to get them on and off, then tq to spec with tq wrench.

when the studs were installed, they were put on by hand torque, no tools involved.

mooty

seriously i think you are too gentle.
watch grand am guys. you need to be mean and brutal to the wheels.
i bang the wheel on, push them in, wedge them in place with knee, and hand thread the first 2-3 turns, then it's impact gun. then tq to spec.

LVDell

Alright, so I have been slowly but surely getting the car back to it's post track weekend cleanliness. One item up for attention was the studs. I decided to remove all the studs, inspect, clean, and reinstall.

What I noticed is that easily 3-4 of the 5 on each hub were not very tight at all. This leads me to believe that the either (a) the loctite failed; (b) user error in application of the loctite; or (c) the massive temps generated from the PFC01 pads and heavy Turbo broke down the loctite.

My guess is C.

I am going to re-install the studs and monitor them more closely for any movement. The Turbo is officially being retired to weekend car status.

I started priming the wife for a GT3 acquisition. It will probably be a track Miata in the interim though.......

AllanJ

Very odd. I checked mine yesterday and they were all solid. I used a healthy amount of blue loctite when I installed them. I also let the car sit for a full 24 hours without moving it to be sure the loctite cured properly.

Good luck!

LVDell

Allan, which thread locker (brand, color, and number) did you use?

I used Permatex High Temperature Red threadlocker #27200 in the blue bottle. The data sheet claims temps up to 450F. Not sure what temps the brakes could transfer to the studs but I imagine it's pretty close if not more than that.

AllanJ

Brand: Loctite
Color: Blue
Full name on package: Loctite Blue Threadlocker



My torque wrench may have been pooched back when I installed these so there is a chance I used more than the 18ft-lbs or whatever I was supposed to use to torque the studs into place.

I used two healthy blobs of loctite on the studs, 180 deg apart. Torque into place, bolt on wheel, let sit for 24 hours minimum.

Your red threadlocker should be stronger than mine so maybe you didn't use enough or moved the car around shortly after installing them to weaken the joint? I don't know. The studs will get freakin' hot though.

AllanJ

...oh yeah, did you clean the studs prior to bolting them in?

LVDell

Clean the actual studs? They were new from the manufacturer in a plastic sealed bag. There was nothing to clean.

Today though I cleaned the studs as well as the threaded holes in the hub to get them as clean as possible before re-application.

I'm done for the day so I'll work on that tomorrow.

TurboCup87

maybe some machining lubricant or preservative on them could cause adhesion issues? Suspect that heat is the biggest issue.

AllanJ

That's what I was thinking of. I'm in the habit of using IPA or lacquer thinner to clean metal before paint or adhesives like loctite.
Probably, especially if the bond is weak due to surface contamination.