Bono

I have read alot of negative comments on Center Lock wheels, and just thought I would post the positive experiences I have had so far. Have had my 2011 GT3 for only a few months and one track event, but I am a frequent tracker and had to deal with any CL issues right away. I bought a used 4x Williams torque multiplier for $125 off of ebay as soon as I bought the car and read (several times) and followed the follow-up bulletin someone posted on revised CL grease and torque instructions released by porsche. My first track event in the car went great, without any issues, and I actually found it very straight forward to have to check/torque only 4 nuts (1 for each wheel). I think you have to get exactly the right tools and be mechanically inclined, but beyond that the CLs have been a good experience for me.

Bono

actually meant to type GT3 above..absolutely amazing car..

triode

^...so far. But many experienced track rats have had outright failures despite purportedly following proper procedure.

Bono

Thanks, I seriously appreciate others opinions on this and take it very seriously. I don't need a wheel coming off at 140mp+ at Road America. How in particular do they fail?..seems like such a good system with proper grease and spleen locking mechanism.

997gt3north

Bono - you can edit your original message for future reference

mdrums

Wait till you bleed/flush your brakes...you'll be cursing Porsche and its stupid pouser idea of center locks

ReneS

I have CL as well and after dealing with them for 4 month now I am in peace with them.
Although the problems are not gone

What always happens is that the locking pin does not come out. Easiest fix is a 10mm(or 8mm?) screw and wiggling it around. 19 out of 20 times the pin pops out. Every once in a while I have to loosen the CL and re-torque it.
Keeping it clean an greased is a must. Although the surface where the wheel and nut meet should not be greased.
CL can be loosened while on the ground(easier) but have to be torqued in the air. Called head mechanic at Porsche Zentrum Stuttgart and he emphasized this!

Another problem I encounter only when driving the car hard is that the wheels and subsequently the CL get very hot and the pin is locked and will not go back in.

Fix here is to use the CL tool and hit it with a rubber or plastic hammer. So far if I grease plenty it seems to not get stuck...

Worst experience with CL was that they actually came loose. Not to the point where I could have lost the wheel but I felt it in turns. the steering wheel was "shacking" a lot. I stopped, loosened(which I was able to do with one hand!) and torqued the nuts and the shacking was gone. So they do come loose and checking them is needed and well advised...

Bono

I want to stay constructive, so I'll just simply ask, how do centerlock wheels make flushing or bleeding the brakes any harder? I bleed my brakes before every event and did before my last, but don't understand how the centerlocks even come into play here?

Bono

ReneS.. you've got my attention. How did one of your wheels come loose? That is seriously frightening. How can it possibly come loose if torqued and spleen/lock engaged?

JJE997.2RS

Holy crap man. This is why people are complaining in the first place.
This shouldnt happen.

What I don't understand about the system is the play that is built in the locking nut. Even if you torque the wheel down, it can rotate 10 or so degrees relative to the locking nut. I can see how if it is done violently enough, the locking nut can shear and then you have a loose wheel.

Carrera GT system just seems easier

Bono

For anyone else that has feedback, it would be great to hear hard facts. If nut/hardware is greased properly and torqued to 444 ft. lbs. and the locking mechanism is engaged properly how did it come loose for the people that report problems? ReneS talked about a nut coming loose enough to turn by hand..how did it happen? If there are hard facts of it happening that don't involve user error, i'm going to seriously think about switching out.

JJE997.2RS

Run a simple experiment. Take your wheels off. Then just put the central bolt and locking nut it. Tell me if there is a way for it to move?

What you will see is that it CAN and WILL move about 10 degrees. In a perfect world, where everything is perfect, nothing will happen. But, the ability for it to fail is there. All we can do is go about and try and follow the procedure as best as we can. But the center locks HAVE failed. There are many instances documented in this very forum.

ir_fuel

IMHO that is simply not possible if the splines are correctly engaged. And even with the spline in the "unlocked" position it still seems a bit weird.

Try this for yourself: Next time you remove a center lock nut, instead of screwing it on using the tool Porsche provided us, just use your bare hands. You will notice that at a certain point the locking mechanism will simply prevent you from tightening the nut any further without using the correct tool that presses the locking mechanism whilst turning. Once you get to that point have a look on how far you sill have to tighten for the nut to get completely seated against the wheel, let alone actually exercise tightening force.

Unless someone can correct me I really do not see a possibility of turning the nut by hand, unless it is so loose it is about to completely fall off. No way your hubs can withstand that abuse without severe damage from the wheel moving around.

my 2 cents

tcsracing1

OP:

give it time

medpilot105

That's just it, Bono. Hard facts are hard to come by. You've a great attitude towards the whole thing and I have to agree with you.

There are too many variables (albeit a few consistent indicators) reported on any forum for any one person to conclusively decide if the failures are directly related to poor design or otherwise poor/improper maintenance. I do agree with the consensus around here that the design isn't truly anything we need, nor is it anything that benefits us. In fact, this whole thing could be a study in human factors and how it relates to the events leading up to an accident. The design and the relatively complicated instructions have me on a Reagan-esque 'trust but verify' stance with these things but every time the wheels and nuts come off, they verify correct and good. "Correct" that I followed the procedure and "Good" that the procedure works.

I've only just started down this road with CL's (6,000 odo miles, 3 track days, and ~3.8 track hours on the hubs) and so far, all is well. Yes, they require more specific and deliberate attention than other systems but I've done three track days in the last month and they were fine. Time will tell.

CL's are not my favorite part of this car, by any means, but they're not going to keep me from enjoying the car to its fullest.

I really feel horrible for the folks who have had accidents. Beautiful cars ruined by a device that really only serves as a bullet point in a marketing presentation. But, I do not expect Porsche to ever assist owners in understanding the process of using and maintaining CL's beyond what's printed in the Owner's Manual Supplement sitting in our glove boxes. That's all they say we need. I don't really agree but it appears, in my case so far, that it's true. And, besides. They specifically tell us in the OM that changing wheels should be an Authorized Porsche Dealer task. Not that they do it right, either. I found 3 splines not engaged after a PPI at a Porsche dealer out of state. Thankfully, my local dealer is good with this stuff and doesn't mind me watching and double-checking.

Thanks to Rennlist and the folks here, like you I was able to get a head start on the proper tools, the bulletins, the stories and, of course expert opinions , before taking the plunge with the 997.2 GT3. Glad I did. Now, it's about remaining methodical, cautious and ever-vigilant.

*** EDIT to add pics ***

Oh, and piggy-backing from another thread about wheels loosening, I marked my wheels and CL bolt's prior to this past weekend of eight sessions over two days at Infini-sears-noma-point-eon Raceway. Zero movement. I used tape and a Sharpie pen to mark the wheel directly adjacent to the 'Stop' point on the CL bolt. Top two pics are the Left Front (before on top, after on bottom) and the bottom two pics are the dreaded Right Rear (again, before on top, after on bottom).

However, I am going to go try out what JJE997.2RS mentioned to learn a little more about the inner workings and watch the movement without the wheel mounted. Thanks for the idea!