How do you check center lock torque before track event?
02-07-2018, 10:19 AM
#1
How do you check center lock torque before track event?
Hey guys,
Quick question here. I understand the procedure for installing a center lock wheel and ensuring it's properly torqued. I understand that you tighten and then loosen and then tighten again and all that.
What I'm wondering here is what you do before a track event just to ensure they're good to go?
Is it enough to just put the torque wrench on it with the car on the ground and verify it's at least 443 ft-lbs or do you actually have to jack up each corner and effectively re-install each one?
Quick question here. I understand the procedure for installing a center lock wheel and ensuring it's properly torqued. I understand that you tighten and then loosen and then tighten again and all that.
What I'm wondering here is what you do before a track event just to ensure they're good to go?
Is it enough to just put the torque wrench on it with the car on the ground and verify it's at least 443 ft-lbs or do you actually have to jack up each corner and effectively re-install each one?
02-07-2018, 11:24 AM
#2
Hey guys,
Quick question here. I understand the procedure for installing a center lock wheel and ensuring it's properly torqued. I understand that you tighten and then loosen and then tighten again and all that.
What I'm wondering here is what you do before a track event just to ensure they're good to go?
Is it enough to just put the torque wrench on it with the car on the ground and verify it's at least 443 ft-lbs or do you actually have to jack up each corner and effectively re-install each one?
Quick question here. I understand the procedure for installing a center lock wheel and ensuring it's properly torqued. I understand that you tighten and then loosen and then tighten again and all that.
What I'm wondering here is what you do before a track event just to ensure they're good to go?
Is it enough to just put the torque wrench on it with the car on the ground and verify it's at least 443 ft-lbs or do you actually have to jack up each corner and effectively re-install each one?
Jack up each side, helper (or clamp) to hold the brake, torque to spec, loosen 1/4 turn, torque to spec, check that lock pins are fully engaged.
02-07-2018, 11:59 AM
#3
Rennlist Member
It shouldn't change. That's the point of the locking mechanism inside the centerlock (hence the name). Once tightened and the locks are released, the nut should not move.
Now if your locks are not engaged, well that's a different story.
Now if your locks are not engaged, well that's a different story.
02-07-2018, 12:11 PM
#4
Drifting
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I’ve experienced this myself in a 2010 GT3 that had the street centerlocks. The locking pins were correctly engaged, but a couple of the nuts were loose.
02-07-2018, 12:14 PM
#5
This is what I'm wondering. You take the car for a track inspection and assume they've done it right but how do you check? With regular 5-bolts you just hit each one with the torque wrench to be sure. We do it to everyone during tech at the track.
I was kinda hoping the same might hold for center locks. Just to make sure.
Ok, so if YOU were the last one to touch them and you're confident in your work, then it's enough to just look at each one and ensure the lock is engaged? Just pop off the dust cap and take a peek?
02-07-2018, 12:22 PM
#6
I think the idea is that they will not be able to back off, but the parts can stretch - that is to say experience plastic deformation instead of elastic.
This is probably only in extreme circumstances, but that is the reason for the procedure.
This is probably only in extreme circumstances, but that is the reason for the procedure.
02-07-2018, 12:36 PM
#7
[QUOTE=Wild Weasel;14784181]Well that's how you set the torque. Are you saying there's no way of knowing it was set properly without just starting over?
This is what I'm wondering. You take the car for a track inspection and assume they've done it right but how do you check? With regular 5-bolts you just hit each one with the torque wrench to be sure. We do it to everyone during tech at the track.
I was kinda hoping the same might hold for center locks. Just to make sure.
The full factory procedure. This is what I do. It is a PITA but not worth the risk to short cut. After any wheels off service by anyone, I re-do them myself. Once I came back from a dealer who installed a new set of tires and 3 of 4 CL pins were not engaged.
This is what I'm wondering. You take the car for a track inspection and assume they've done it right but how do you check? With regular 5-bolts you just hit each one with the torque wrench to be sure. We do it to everyone during tech at the track.
I was kinda hoping the same might hold for center locks. Just to make sure.
The full factory procedure. This is what I do. It is a PITA but not worth the risk to short cut. After any wheels off service by anyone, I re-do them myself. Once I came back from a dealer who installed a new set of tires and 3 of 4 CL pins were not engaged.
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02-07-2018, 01:29 PM
#8
Rennlist Member
I don’t believe that to be true. The locking mechanism merely prevents the nut from coming off (unthreading) , it does not prevent it from loosening (loosing torque).
I’ve experienced this myself in a 2010 GT3 that had the street centerlocks. The locking pins were correctly engaged, but a couple of the nuts were loose.
We have many cars come through the my shop with Center Locks. All my customers bitch at me about how hard they are to use and change etc,etc. They hate that I charge them for a center lock service every time. BUT, never had one come loose, out of hundreds of wheels.
02-07-2018, 01:31 PM
#9
Rennlist Member
Yes. This is all many PCA regions will do as they do not want assume the liability of doing the full scenario on a wheel.
02-07-2018, 01:42 PM
#10
Rennlist Member
[QUOTE=zedcat;14784263]
During in a track weekend, assuming 4-5 20-30min sessions per day, how often would you go through the full re-torquing process?
Well that's how you set the torque. Are you saying there's no way of knowing it was set properly without just starting over?
This is what I'm wondering. You take the car for a track inspection and assume they've done it right but how do you check? With regular 5-bolts you just hit each one with the torque wrench to be sure. We do it to everyone during tech at the track.
I was kinda hoping the same might hold for center locks. Just to make sure.
The full factory procedure. This is what I do. It is a PITA but not worth the risk to short cut. After any wheels off service by anyone, I re-do them myself. Once I came back from a dealer who installed a new set of tires and 3 of 4 CL pins were not engaged.
This is what I'm wondering. You take the car for a track inspection and assume they've done it right but how do you check? With regular 5-bolts you just hit each one with the torque wrench to be sure. We do it to everyone during tech at the track.
I was kinda hoping the same might hold for center locks. Just to make sure.
The full factory procedure. This is what I do. It is a PITA but not worth the risk to short cut. After any wheels off service by anyone, I re-do them myself. Once I came back from a dealer who installed a new set of tires and 3 of 4 CL pins were not engaged.
02-07-2018, 01:52 PM
#11
[QUOTE=tgibrit;14784475]My basic routine is at the start of each day. Depending on the track I may also swap tires side to side during the weekend.
02-07-2018, 02:47 PM
#12
Looks like I'll have to make a habit of re-doing them any time I get it back from a shop though. So that's annoying.
Not sure it's been said in this thread yet, but center locks suck ***** and it's crap that Porsche forces them on us.
02-07-2018, 04:19 PM
#14
Drifting
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I suggest you do some searches in the 997 GT3 forum on terms such as ‘centerlock failure’ and similar. You’ll find loads of folks sharing horror stories. In fact, the guy who bought my 2010 GT3 had a wheel come off the car while on-track at high speed. It was sheer luck no one was hurt. This was just one of many catastrophic failures that forced Porsche to do a quick rethink of the procedure and torque specs for centerlocks.
02-07-2018, 04:33 PM
#15
Rennlist Member
I own 2 997 GT3RS's and a 991 GT3 personally myself, so have pretty good first hand knowledge of the center lock issue's. I have been on track and had a 997GT3 loose a wheel in front of me. That car had non standard wheels on it and was re-torqued with the car ON ITS WHEELS ON THE GROUND.
Like I said, never seen a car with the proper technique used with OEM wheels have something come loose. Just looks at an exploded view of the center lock system. Its very apparent how its supposed to work.
Like I said, never seen a car with the proper technique used with OEM wheels have something come loose. Just looks at an exploded view of the center lock system. Its very apparent how its supposed to work.