Centerlock failure
11-24-2011, 09:40 PM
#196
12-24-2011, 02:45 PM
#197
I lost a wheel during tourist driving at Nurburgring Nordschlife with my 997 GT3 MkII. The car had 14000 km with no mechanical issues. I had old center locks (recall was not done).
12-24-2011, 04:23 PM
#199
But it was hub, not center lock failure! If I'm not mistaken, then you do a recall they do not replace hubs. I have no idea why it failed. May be 600 N.m was too much torque for old CL
12-24-2011, 05:11 PM
#200
Track Day
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OMG....!! Looks like the brunt of the energy was dissipated in the straight spin out..., I don't think that you would have walked away if it had happened while hard cornering.., You got lucky after all.
12-24-2011, 05:46 PM
#201
Rennlist Member
It happened this summer. Porsche did not cover the damage, because recall was not done. I got recall letter two weeks before accident, but had no chance to visit Porsche dealer to replace CL.
But it was hub, not center lock failure! If I'm not mistaken, then you do a recall they do not replace hubs. I have no idea why it failed. May be 600 N.m was too much torque for old CL
But it was hub, not center lock failure! If I'm not mistaken, then you do a recall they do not replace hubs. I have no idea why it failed. May be 600 N.m was too much torque for old CL
The likely reason for the failure was wear on your hubs as you likely had and ran the car at 500Nm before they advised to tighten to 600Nm for track use. As part of the recall, Porsche dealers were required to inspect the hubs for signs of wear and to replace.
My car was an 02/10 build and the first TSB to increase torque was late in 2010. I had done at least a couple of trackdays at 500Nm by this point... When I took the car in for the recall to be done, the dealer stated there were signs of wear on the rear hubs and they were replaced.
Regretfully you were probably in a similar situation where you'd used your car at the lesser torque in the early stages of ownership. Its a shame they didn't get you sooner as they would hopefully seen it and replaced them prior to the failure.
Hopefully its as good as new now in any case...
12-24-2011, 05:58 PM
#202
Race Director
The last 2 times I went to remove my rear wheels I'm finding the locking part that is on the spring is stuck and will not push in. I have to take a 1/2" drive extension and pop it in with a punch of my hand. Then when I go to back off the center lock it does not feel as tight as I originally torque it.
Any ideas????
Any ideas????
12-24-2011, 06:23 PM
#203
Rennlist Member
The last 2 times I went to remove my rear wheels I'm finding the locking part that is on the spring is stuck and will not push in. I have to take a 1/2" drive extension and pop it in with a punch of my hand. Then when I go to back off the center lock it does not feel as tight as I originally torque it.
Any ideas????
Any ideas????
Sounds like your centrelocks are backing off a tad and locking against those locking pins... To be honest, never happens to me even after the recall but some guys have mentioned it previously...
Make sure the mounting surface on your wheels is always clean where it would rest against the rotor hat and always put a light smear of optimoly grease on the centrelock seating surface of your wheel before torquing to ensure that the full torque applied goes towards tightening rather than overcoming friction. I also pull those locking mechanisms out and put a light smear on the threads that the centrelocks engage... Whenever I try to take wheels off, those pins move freely and the wheel is tighter, that is, harder to get off...
Maybe get your torque wrench checked and calibrated to ensure it is torquing to the specified torque...
Hope this helps...
12-24-2011, 08:27 PM
#204
Rennlist Member
It happened this summer. Porsche did not cover the damage, because recall was not done. I got recall letter two weeks before accident, but had no chance to visit Porsche dealer to replace CL.
But it was hub, not center lock failure! If I'm not mistaken, then you do a recall they do not replace hubs. I have no idea why it failed. May be 600 N.m was too much torque for old CL
But it was hub, not center lock failure! If I'm not mistaken, then you do a recall they do not replace hubs. I have no idea why it failed. May be 600 N.m was too much torque for old CL
The last 2 times I went to remove my rear wheels I'm finding the locking part that is on the spring is stuck and will not push in. I have to take a 1/2" drive extension and pop it in with a punch of my hand. Then when I go to back off the center lock it does not feel as tight as I originally torque it.
Any ideas????
Any ideas????
12-25-2011, 04:38 AM
#205
Rennlist Member
@ Krisa9977: Happy to hear you are ok. Could have been much worse. What happened to the driver's door ?
Did the safety marshals cut it open, or did the armco go inside ?
Did the safety marshals cut it open, or did the armco go inside ?
12-25-2011, 07:21 AM
#206
Rennlist Member
12-25-2011, 07:44 AM
#207
Nordschleife Master
Mdrums
Like 911rox said, a coating of grease is critical for each torque cycle
The only time I have had this problem is if I forget to grease....the wheel doesnt take all the torque
Also apply all torque in air
Like 911rox said, a coating of grease is critical for each torque cycle
The only time I have had this problem is if I forget to grease....the wheel doesnt take all the torque
Also apply all torque in air
12-25-2011, 12:46 PM
#208
Still plays with cars.
Lifetime Rennlist
Member
I've seen failures here and when the hub fails it is usually blamed on over torquing the wheels ...
12-25-2011, 12:50 PM
#209
Race Director
You guys know anywhere to get my torque wrench checked in Florida?
12-25-2011, 01:23 PM
#210
That is a steel rotor in combo with a PCCB caliper. So the car was molested after it left the factory. I feel quite confident in believing that whoever re-installed the wheel didn't follow procedure. After many remove/installs my CL nuts and hubs look pristine. I continue to see incorrect CL installation trackside.