Newbie CL question
01-28-2014, 07:23 PM
#31
Rennlist Member
[QUOTE=SamFromTX;11086758]
If you track, you are crazy for not being intimate with the process - not to mention you need to re-torque the wheels every morning. QUOTE]
Is it OK to re-torque at the track side without lifting the car? I assume the nut is seated enough that it should be OK but am intereted in opinions.
No! The wheels being torqued MUST be off the ground to ensure they are sitting flush against the hub without external forces when torquing...
If you track, you are crazy for not being intimate with the process - not to mention you need to re-torque the wheels every morning. QUOTE]
Is it OK to re-torque at the track side without lifting the car? I assume the nut is seated enough that it should be OK but am intereted in opinions.
01-28-2014, 07:37 PM
#32
Rennlist Member
Research and know the procedure intimately yourself...
Changing Cl wheels is not a big deal as long as you do it correctly. And it really is not hard at all. Just because you take it to the dealer does not mean it was done correctly. They make mistakes too and consider that the tire and wheel guys there are many times the most junior in the shop.
I change out mine myself. Of course it really helps to have a lift! My recommendation would be to personally check the locking mechanism each time there is a wheel change regardless of who does it for you.
Walt
I change out mine myself. Of course it really helps to have a lift! My recommendation would be to personally check the locking mechanism each time there is a wheel change regardless of who does it for you.
Walt
I would not rely on the dealer, they have yet to do mine correctly when doing any tire work - I think the Austin shop does not use techs for tire work. Both times they have touched my tires, they have totally messed up the CL process. Once was so bad, I had them flat bed the car back to the dealer to make sure there was no damage. I could turn the nut with my hand when I got home. They were very embarrassed the first time, but it happened again.
If you drive on the street, at least be aware of the process and maybe have the dealer do it in front of you to make sure it's done right on your car. The process is pretty silly when you step back from it, and I can imagine your average tech thinking so, and just waving off any precautions and doing what they think is good enough - which is to treat it like one big lug nut.
If you track, you are crazy for not being intimate with the process - not to mention you need to re-torque the wheels every morning. If you have track support sitting next to you the whole time, maybe no need to worry about it...
If you drive on the street, at least be aware of the process and maybe have the dealer do it in front of you to make sure it's done right on your car. The process is pretty silly when you step back from it, and I can imagine your average tech thinking so, and just waving off any precautions and doing what they think is good enough - which is to treat it like one big lug nut.
If you track, you are crazy for not being intimate with the process - not to mention you need to re-torque the wheels every morning. If you have track support sitting next to you the whole time, maybe no need to worry about it...
CLs are not too hard for the average Joe to handle, they do however require some smarts, and someone to be thorough and meticulous with the process... Your 'average' mechanic at the dealership won't exactly be going off the IQ charts, won't care all that much and they won't always be getting the master techs to bolt on wheels...
Your car, your choice really but ignorance ain't bliss where CLs are concerned... Just my 2 cents...
Last edited by 911rox; 01-28-2014 at 08:05 PM.
01-28-2014, 08:07 PM
#33
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I was too cheap to buy a long metal stick as a breaker bar for my 997.2 CL, so I used the Precision Tool torque wrench (minus the actual torque calibration piece) and slide on a floor jack handle. Though I have to point out that the handle is from the Harbor Freight 3ton jack. The 1.5ton one won't fit (too skinny).
01-28-2014, 10:23 PM
#35
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By the way, how can CL wheels get loose at the track? I thought the locking pin is there to prevent them from coming loose. Or did I misunderstand the design?
01-28-2014, 11:08 PM
#37
[QUOTE=SamFromTX;11086758]
If you track, you are crazy for not being intimate with the process - not to mention you need to re-torque the wheels every morning. QUOTE]
Is it OK to re-torque at the track side without lifting the car? I assume the nut is seated enough that it should be OK but am intereted in opinions.
The way it was explained to me by an engineer was that you don't want any of force being provided by the nut to be used to overcome the deflection of the wheel/tire on the ground. And while in most cases there is very little, it's simpler just to say wheel off the ground than to try to describe what other conditions are safe/unsafe.
If you track, you are crazy for not being intimate with the process - not to mention you need to re-torque the wheels every morning. QUOTE]
Is it OK to re-torque at the track side without lifting the car? I assume the nut is seated enough that it should be OK but am intereted in opinions.
01-29-2014, 12:47 AM
#38
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I meant not the track incidents of the previous model but rather what was mentioned in this thread that you need to torque CLs between track days/session. Shouldn't the lock prevent it from loosening in the first place?
01-29-2014, 01:10 AM
#39
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Sitting back and thinking the dealer's got you covered is naive. Take that attitude and when your wheel flies off on the freeway at 80, you can scream your dealers name as you careen off other cars and then the wall.
I've seen more cars f'd up by dealers than I have by people changing their own wheels. I relayed the story to Mike about seeing a brand new 997 TTS show up at a PCA gathering with all four splines disengaged. When I found the owner and explained what was wrong, he went back to the dealer and complained. The dealer tried to tell him that everything was fine. I faxed the dealer the service bulletin showing proper engagement. They had a big "oh ****" moment and changed their tune. Truly frightening.
I've seen more cars f'd up by dealers than I have by people changing their own wheels. I relayed the story to Mike about seeing a brand new 997 TTS show up at a PCA gathering with all four splines disengaged. When I found the owner and explained what was wrong, he went back to the dealer and complained. The dealer tried to tell him that everything was fine. I faxed the dealer the service bulletin showing proper engagement. They had a big "oh ****" moment and changed their tune. Truly frightening.
01-29-2014, 01:30 AM
#40
Rennlist Member
The secondary locks stop the CL bolts backing out, not from losing tension. In saying that I think they are overdoing it with suggestions of checking between sessions. I'll check before each trackday and do 3-400 track kms on the day plus another that much to/from track with no issues. If anything, they are always harder to crack off after having been on track...
01-29-2014, 02:34 AM
#41
The expansion and contraction of the hubs/bolts etc due to extreme heat can cause the tension of the bolts to drop. Sure they won't come loose but if the tension drops, you get tiny movements under load that then have detrimental effects on the hubs and eventually failure.
The secondary locks stop the CL bolts backing out, not from losing tension. In saying that I think they are overdoing it with suggestions of checking between sessions. I'll check before each trackday and do 3-400 track kms on the day plus another that much to/from track with no issues. If anything, they are always harder to crack off after having been on track...
The secondary locks stop the CL bolts backing out, not from losing tension. In saying that I think they are overdoing it with suggestions of checking between sessions. I'll check before each trackday and do 3-400 track kms on the day plus another that much to/from track with no issues. If anything, they are always harder to crack off after having been on track...
All together a frightening system when you consider the mode of failure that is occurring - the tube that the CL nut screws into basically shears off when weakened by cyclic loading (which is aggravated by any wheel-hub interface movement that allows larger moments to get into this tube).
01-29-2014, 03:34 AM
#42
Rennlist Member
Absolutely DO NOT torque between track sessions.
As the hub heats up the metals slightly contract allowing you to over torque the nut. Check it at the beginning of the day.
Walt
As the hub heats up the metals slightly contract allowing you to over torque the nut. Check it at the beginning of the day.
Walt
01-29-2014, 12:31 PM
#44
Rennlist Member
I agree it is worthy to be familiar with the process but to claim the Porsche dealership do not know what they are doing is a stretch. I do not plan to switch tires for track events. Any work done on the CL's will be done either by my dealer or someone who I believe knows what they are doing.
I am not track junkie and not handy with tools and I will leave the mechanically work done on the car with people who are trained to do it.
I am not track junkie and not handy with tools and I will leave the mechanically work done on the car with people who are trained to do it.
01-29-2014, 12:57 PM
#45
Rennlist Member
It's about as complicated as changing your oil or baking cookies. Simple procedures that have to be followed in a certain order.
Years ago I took my Datsun 280Z to the dealer to have an oil change. Following that and on the highway I started to see billowing smoke coming up around the hood. I immediately pulled over and shut down the engine. When I opened the hood I discovered the oil cap missing. I'm sure the tech knew how to do an oil change! Something he had probably done hundreds of times before. My point being there are a few thing that you can trust your tech with but MUST verify, in my opinion.
Walt
Years ago I took my Datsun 280Z to the dealer to have an oil change. Following that and on the highway I started to see billowing smoke coming up around the hood. I immediately pulled over and shut down the engine. When I opened the hood I discovered the oil cap missing. I'm sure the tech knew how to do an oil change! Something he had probably done hundreds of times before. My point being there are a few thing that you can trust your tech with but MUST verify, in my opinion.
Walt