Wheel studs- worth checking and/or replacing
02-17-2014, 03:56 PM
#31
Nordschleife Master
Studs break, but so do wheel bolts, albeit not nearly as frequently.
Don't get lulled into a false sense of security because you are still using bolts.
Who the heck knows what the contributing factors are, so be proactive and replace at "some" interval.
Don't get lulled into a false sense of security because you are still using bolts.
Who the heck knows what the contributing factors are, so be proactive and replace at "some" interval.
02-17-2014, 05:01 PM
#32
Rennlist Member
Thread Starter
Alternate Theory:
Maybe the brake rotor failed first (when you felt the "clag") and then when you hit the brakes the center of the rotor interfered with the main part of the rotor and that tore up the studs.
It seems odd to me that if the 5 studs just broke, why would the center of the rotor gotten destroyed? I assume you hit the brake and that should have stopped the rotor.
Just thinking...
Maybe the brake rotor failed first (when you felt the "clag") and then when you hit the brakes the center of the rotor interfered with the main part of the rotor and that tore up the studs.
It seems odd to me that if the 5 studs just broke, why would the center of the rotor gotten destroyed? I assume you hit the brake and that should have stopped the rotor.
Just thinking...
02-17-2014, 05:37 PM
#34
Nordschleife Master
Center of the Rotor could have gotten destroyed from the impact of hitting the ground / gravel.
Torque check should have no appreciable effect on the fatigue strength, provided nothing moves.
Torque check should have no appreciable effect on the fatigue strength, provided nothing moves.
02-18-2014, 11:54 AM
#38
It looks like the studs got bound to the face of the brake rotor hub as the wheel fell off, shearing the face of the hub off with the wheel. I'd expect to see the hub face on the other side of the wheel holding those studs in place?
02-18-2014, 01:06 PM
#39
I bet if you put a lug wrench on the loose wheel you could spin those lugs fairly easily.
Nasty failure and the outcome could have been a whole lot worse. I don't recall if it was asked, how old were the studs?
-Mike
02-18-2014, 02:00 PM
#40
Rennlist Member
Thread Starter
Sorry for the delay in response as I was traveling and this is my first day back at work in 2 weeks.
I no longer have first hand visual info to share but the studs are still in the wheel because as I recall they were not cleanly sheared but slightly bent/twisted. as they let go.
We'll be doing more forensic work on this so thanks for all the suggestions. I'll post an update once I receive one.
Btw the studs were over 80+ hrs old and torqued to just over 90 ft/lbs.
I no longer have first hand visual info to share but the studs are still in the wheel because as I recall they were not cleanly sheared but slightly bent/twisted. as they let go.
We'll be doing more forensic work on this so thanks for all the suggestions. I'll post an update once I receive one.
Btw the studs were over 80+ hrs old and torqued to just over 90 ft/lbs.
02-18-2014, 02:58 PM
#41
Rennlist Member
When you stated you torqued the studs to 90 ft.-lbs, you really mean the wheel nuts, right? The torque for mounting the studs to the hub should only be 15-20 ft.-lbs.
02-18-2014, 03:17 PM
#42
Rennlist Member
Thread Starter
02-18-2014, 06:35 PM
#43
Nordschleife Master
Join Date: Oct 2004
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My wrench Dan @ The Speed Gallery just reminded me of when the 2 little screws that hold the rotor to the wheel carrier backed out of one of my rears wheels. When I tightened the wheel I could see it didn't fit properly and called him over to look. He removed the wheel and sure enough, those 2 little screws had backed out just enough to keep the wheel from fitting tightly against the rotor hub. It would be easy to miss and going out like that could easily cause enough vibration to break off studs but also could break off the little screws leaving a void between the wheel and the rotor. Either way could be catastrophic....
