Finally got out on track in warm California sunshine this past weekend. Did my first time out with NASA at Thunderhill. What an overwhelming crowd! I had to paddock on the grass!

So, as you can see, I got new GMG wheels. Ø19" painted silver. They are shod with Hoosiers. I bolted them on early Saturday morning for the 1st time and took to the pit lane and onto the track. However, I did hear a slight scraping sound from my right rear. I figured it was no big deal, the car felt fine and I'd check it out after my session. Well, I'm a bit lazy, so I didn't pay much more attention until the next morning. That noise was getting much louder and at speed on track the car felt like the wheels were out of balance. I figured that shudder was probably due to tire spin on the rim. I had not gotten a chance to mark the tire at the valve stem to check that.

Luckily, it was a Porsche Racing Club weekend, so there was a large contingent of PRC guys nearby. I asked one of them if he would take a listen/look at my car as I slowly crept it in the paddock. He immediately said "you've got a loose wheel". I was rather surprised by this, as I had thought it was something actually rubbing. Sure enough, I jacked it up and put the 4' breaker bar on the nut and the breaker bar actually swung to the ground under it's own weight! That nut was about to come off, just like the Toro Roso F1 car in Shanghai this weekend! Ouch!!! I took the wheel off anyway, just to sniff around to see if anything else was wrong. As I pulled the nut off, the cone stuck to the wheel. After I got the wheel off the car, I pried the cone out and found that there was a very thick build-up of the Castrol grease. The grease had solidified like stone. It took some solvent and a lot of elbow grease to clean it off. The wheel side was even worse. As I went to put it all back together and re-grease, I discovered that the washer between the nut and cone was missing. I'm guessing that had something to do with the nut coming loose.

So, then I check the torque of all the remaining wheels and, to my horror, found them to be loose as well. No where near as loose as the right rear, but not 600NM.

The rubbing/creaking sound went away and I happily ran the rest of my sessions. Now I've got to unbolt all those nuts and reinstall the washers.

Pics from the day...

 

Having trouble with attaching photos today. Here they are...

 

Here is a detailed picture of the hub. Note the red cones and how they were gauled by the wheel not being tight on the hub. I assume this is why Porsche recommends that you change out this hardware every time you change the rotors. They looked brand new before the track wheels went on! This is most likely the source of the rubbing/creaking sound that I heard.

 

that sounds scary.

 

glad nothing bad happened

 

I'd say this was a close call, glad you found out before worse things happened. Darn CLs

 

It seems like the CL might be just a bit of a marketing gimmick

 

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."

C/Ls in a street car..

 

Small world!! The guy that helped you is Ron Kain, owner of IPB Autosport. He was telling me the story over beers last night.

 

Glad nothing untoward happened!

Do you remember if the lock core (that springy bit) was sitting flush with the inner bevel of the nut? I had to pry mine out after every wheel change. And AFAIK that mechanism was designed to specifically prevent the horrors you described...

 

Lar- sounds like you dodged a bullet

The hub in the pic looks like it has metal transfer from the wheel?

Who installed and torqued your CL's? How could the washers be missing? Were they torqued with wheel off the ground?

As CRex noted, it is critical that the center splined portion of the CL be FLUSH with outer splines. Otherwise the lock is not locked.

All said with the intent to learn ! Not trying to harass you

After seeing someone working on a car in the pit at Laguna Seca, using an impact gun on the CL's, no lubrication, splines not fully locked, I have been fearful of a bad event.

Guys, it is CRITICAL to follow the proper procedure for removing/installing CL's please, for the sake of your safety and those around you be sure you understand the process and don't shortcut it. Here is a link with the process: https://rennlist.com/forums/997-gt2-...ght=centerlock

Lar I am glad to hear you are ok!

Remember too guys, if you have a noise, get it checked out, it won't get better by itself!

 

God was looking over u that day. If u did an HOD event the wheel woulda come off(inside joke). So u had fun : )? Didn't know u run with NASA. Which group were u in? Laptimes please : ). Mike

 

That's a close one!
Love it that you still were able to track it. The pics are very good.

 

I hate my $#@! centerlocks. Do a search or ask your dealer for a copy of the bulletin on how to torque them properly. Note, you have to torque the #$@! things while they are off the ground! Makes it a two person job, one on the brakes. You have to use special lube on the centerlock mechanism too - every time. Don't lose the plastic caps either, if water gets in there bad stuff happens. Oh, and make sure the screws in the red nubs are tight every time else the wheel won't seat properly. 50 Newton Meters torque (up from the original 400). A step backwards in MHO.

 

this is why i love my 997.1

ok, ok, i still have .2 envy......