Warning: Centerlocks Losing Torque
07-04-2012, 10:56 PM
#93
Nordschleife Master
Your life is not worth risking. You have kids, I don't..
Let the bidding begin
07-04-2012, 11:02 PM
#95
Nordschleife Master
Based on centerlocks being a bad design I will put the offer out there
I will buy any gt3rs fit bbs for $1,000 a set.
They are dangerous and I will take them off ur hands
I will buy any gt3rs fit bbs for $1,000 a set.
They are dangerous and I will take them off ur hands
07-04-2012, 11:25 PM
#98
Rennlist Member
Would you pay 0.16 on the dollar for a very nice CL hub set taken off my GT3.2 a week after the CL recall check up? 
Mike told me I should keep them (and my wheels, now long gone 
).......but now.....OMG now!!!...... they are just worthless paperweights or garage decor. 
).......but now.....OMG now!!!...... they are just worthless paperweights or garage decor.
07-05-2012, 01:20 AM
#100
Rennlist Member
....my wife was pissed off at first, but after I referred her to the Porshe Tech bulletins, she sez its OK......cuz safety is Job 1.....
07-05-2012, 01:31 AM
#101
RL'ers tracking centerlock cars, take heed:
Facts:
Observations:
Immediate Thoughts:
Car is going into the dealership to have all hubs inspected. Will try to push this through as a warranty issue but I have a feeling it will be denied given track use. Regardless of the claim, I'll have the RR hub assembly replaced even if out-of-pocket.
Just when you thought following Porsche instructions to the tee would prevent problems with these fecking CL's...
p.s. can anyone with the official bulletin quoting the 296lbft breakaway threshold please email me a copy so I can confront the dealership with the technical facts? I will obviously not compromise the source in any way...
Facts:
- 2011 GT3RS, mainly tracked
- Driven to track on street tires and switched out to track wheels in the pits
- 30-35 wheel changes in the past 1.5 years, mostly from preventative maintenance and trackside switching as described above
- Car has only been paired with two sets of wheels ever: OEM and Champion RS20s
- Tire pairings: numerous sets of Hoosier R6s, occasionally MPSCs and Trofeos
- Wheel changes performed as per Porsche bulletin--wheels torqued off the ground to 450lbft; contact areas greased with optimoly
- Center splines always in the "secured" position and visually checked by me before each track session
Observations:
- Centerlock nuts typically get tighter over time as the optimoly dries up from heat and binds--logical and no surprise
- Breakaway torque should henceforth exceed 450lbft, though not by much
- Earlier this year I began noticing that the RR (i.e. the passenger side rear for LHD vehicles) CL nut is noticeably easier to loosen than the others
- After a two-day track session this weekend (15 heat cycles and 95 laps of a 4.3km course) the RR nut took less than 300lbft to remove even though it was torqued to 450lbft just 48 hours ago using the same torque wrench
- The five red alignment pins on the RR hub show superficial scratches consistent with the scratches on the 3 other hubs, but MORE SO than any other. Keyword here is more, but not necessarily deeper, and nothing similar to the "problem" pictures in the official bulletin posted here last week
- No unusual signs of wear on the hub, rotor bell surface or wheel mating surface as per said bulletin
Immediate Thoughts:
- Even with the center splines fully engaged, the nut can still turn approx. 20-30 degrees by design
- The RR CL nut appears to have gradually loosened itself from repeated stress on track
- Whether the center spline effectively stopped the CL from further loosening will never be known; wheel may have been taken off in time before further stress was levied on the spline mechanism
Car is going into the dealership to have all hubs inspected. Will try to push this through as a warranty issue but I have a feeling it will be denied given track use. Regardless of the claim, I'll have the RR hub assembly replaced even if out-of-pocket.
Just when you thought following Porsche instructions to the tee would prevent problems with these fecking CL's...
p.s. can anyone with the official bulletin quoting the 296lbft breakaway threshold please email me a copy so I can confront the dealership with the technical facts? I will obviously not compromise the source in any way...
I just read through ALL 100 posts and was surprised that this simple test has NOT been mentioned by the esteemed Trakcar, Savyboy or NJ-GT !
When entering pitlane after a "hot" session, do NOT do a cool down lap BUT come in hot and immediately pull into a pit and have someone hit ALL four CL wheel lugs with a digital Pyrometer. The "temp" readings you will get should instantly tell you if there is a problem with the right rear CL.
Since friction causes major heat build up (rub your hands together fast & hard) and there was ANY friction or movement of the CL during the session then there will be a significant temp variant with that questionable CL compared to the other three. This test MUST be done on pit lane as the wheels WILL cool by the time you get back to your trailer and the variance in temps will have closed up.
Logic would dictate that if you are running on a CW track; The Glen, Road Atlanta, Mid Ohio, Sebring, etc..... then the problem should be happening to the Left rear wheel. If you are running on a CCW track; Laguna, Daytona, etc.... then this problem should be happening to your right rear wheel !
Hope this helps !
07-05-2012, 01:58 AM
#102
Rennlist Member
07-05-2012, 04:07 AM
#103
Instructor
Logic would dictate that if you are running on a CW; The Glen, Road Atlanta, Mid Ohio, Sebring, etc..... then the problem should be happening to the Left rear wheel. If you are running on a CCW track; Laguna, Daytona, etc.... then this problem should be happening to your right rear wheel !
Hope this helps !
Hope this helps !
Last edited by gstahl; 07-13-2012 at 02:04 AM.
07-05-2012, 04:21 AM
#104
Burning Brakes
Just read the whole thread. Another interesting read from the RL community.
CRex: thank you for your objective assessment of your CL issue.
My takeaways:
1. CLs need more attention than 5-lugs
2. No conclusive proof that CLs are technically flawed
3. Humans are not perfect. Lack of attention to detail for CL installation could easily lead to a flaw.
4. Agreement on a subject without conclusive proof will always be divided
5. Piece of mind is key. Bernie chimed in saying he doesn't see an issue and he's never brought it up to me in the past as a concern. Peter & Randy have not seen an issue with as many wheel changes as they have successfully completed. They are both very competent and careful. I trust Rodger/Eddie and Orbit and they have not mentioned CLs as a concern. So, I have piece of mind with my 7.2 GT3 CL's.
For those who have lost confidence in CL's, DO the 5-lug conversion. It's cheap insurance and NOTHING is worse than losing confidence in your car.
CRex: thank you for your objective assessment of your CL issue.
My takeaways:
1. CLs need more attention than 5-lugs
2. No conclusive proof that CLs are technically flawed
3. Humans are not perfect. Lack of attention to detail for CL installation could easily lead to a flaw.
4. Agreement on a subject without conclusive proof will always be divided
5. Piece of mind is key. Bernie chimed in saying he doesn't see an issue and he's never brought it up to me in the past as a concern. Peter & Randy have not seen an issue with as many wheel changes as they have successfully completed. They are both very competent and careful. I trust Rodger/Eddie and Orbit and they have not mentioned CLs as a concern. So, I have piece of mind with my 7.2 GT3 CL's.
For those who have lost confidence in CL's, DO the 5-lug conversion. It's cheap insurance and NOTHING is worse than losing confidence in your car.
07-05-2012, 04:27 AM
#105
Rennlist Member
Thread Starter
Everyone having this latest CL problem has overlooked one VERY important factor that hasn't been mentioned on this thread....... TEMPERATURE !
When entering pitlane after a "hot" session, do NOT do a cool down lap BUT come in hot and immediately pull into a pit and have someone hit ALL four CL wheel lugs with a digital Pyrometer. The "temp" readings you will get should instantly tell you if there is a problem with the right rear CL.
Since friction causes major heat build up (rub your hands together fast & hard) and there was ANY friction or movement of the CL during the session then there will be a significant temp variant with that questionable CL compared to the other three.
Logic would dictate that if you are running on a CW track; The Glen, Road Atlanta, Mid Ohio, Sebring, etc..... then the problem should be happening to the Left rear wheel. If you are running on a CCW track; Laguna, Daytona, etc.... then this problem should be happening to your right rear wheel !
When entering pitlane after a "hot" session, do NOT do a cool down lap BUT come in hot and immediately pull into a pit and have someone hit ALL four CL wheel lugs with a digital Pyrometer. The "temp" readings you will get should instantly tell you if there is a problem with the right rear CL.
Since friction causes major heat build up (rub your hands together fast & hard) and there was ANY friction or movement of the CL during the session then there will be a significant temp variant with that questionable CL compared to the other three.
Logic would dictate that if you are running on a CW track; The Glen, Road Atlanta, Mid Ohio, Sebring, etc..... then the problem should be happening to the Left rear wheel. If you are running on a CCW track; Laguna, Daytona, etc.... then this problem should be happening to your right rear wheel !
In a "true" racecar the CL nut is right-threaded on the left and left-treaded on the right. As we all know by now our CLs are right-threaded on both sides. At braking the force exerted on the right side nuts is counter-clockwise which will attempt to loosen those nuts...
I don't want to jump to conclusion since there are redundancies designed into the system--esp. those red nipples that keep the wheel in place. Any movement thus far has to be real minor otherwise those nipples would be in far worse shape. Nevertheless, the manifest facts are not great at this point.