Jesus bloody Christ - watched him do it!
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A new part is list $399. Takes a little over an hour to install, and then alignment. As to the whys and who is at fault, I would want to know who put it in last, did they use new bolts or the 3rd or 4th time with the same bolt, was it over torqued, etc. I'm not really asking for more info (and you may not know anymore), just saying also as a shop owner there is a lot that goes into these things to assess what took place. I generally want to know this so that I can work with my customer to fix the situation, and hopefully if there was some guilt on my peoples part that we do NOT ever let it happen again. And yes as Dinorcz says it is how the shop deals with it that will tell you something.
In the end, I would fix it. If they take care of you...great...points in Bob's statement are really good.
I stand corrected...I was too harsh....and I'd go with Bob on this.
JB
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Terminator, who did you take your car to? Steven is good with Andy over at Fearnsport, and I'm good with the guys at Parr. You should let a pro handle this, because unfortunately it sounds like these guys are jerking you around. Let me know if you want us to make some calls and get you in - you can send the bill to the idiot that stripped out the bolt.
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Thanks – guys all good points. But the technician who was doing it “felt” as he was slowly tightening the bolt that if he pushes further it will definitely rip the thread. Well, I will fix this one way or the other, but I am more curious about my friend technician (who really is good and highly knowledgeable) saying not to worry about under torque value of 2kg on top bolt.
Let’s discuss this. I know it’s a controversial advice and completely irresponsible even perhaps but he says;
1. Bolt can’t physically undo itself, even if it does it will hit a metal barrier 1cm out with its head.
2. Because of the heat the bolt will stick to aluminium in first couple of heat cycles.
3. From a physics point of view, the bottom bolt when you brake is pulled outwards by the frontwards rotational force of the rotor whilst the top bolt on the calliper is actually jammed inwards.
4. The calliper will never come undone. If the top bolt loses grip and the bottom loses grip (the most unlikely scenario) you will hear calliper moving and clacking on brake application before anything serious could actually occur.
Gentlemen opinions please?
PS. I have been irresponsible and have braked full on from 170mph+ to 0 three times. Taken my wheel off and checked that bolt. Holding as was at the moment @ 65nM but I don't want to tighten further in case it rips the thread.
Let’s discuss this. I know it’s a controversial advice and completely irresponsible even perhaps but he says;
1. Bolt can’t physically undo itself, even if it does it will hit a metal barrier 1cm out with its head.
2. Because of the heat the bolt will stick to aluminium in first couple of heat cycles.
3. From a physics point of view, the bottom bolt when you brake is pulled outwards by the frontwards rotational force of the rotor whilst the top bolt on the calliper is actually jammed inwards.
4. The calliper will never come undone. If the top bolt loses grip and the bottom loses grip (the most unlikely scenario) you will hear calliper moving and clacking on brake application before anything serious could actually occur.
Gentlemen opinions please?
PS. I have been irresponsible and have braked full on from 170mph+ to 0 three times. Taken my wheel off and checked that bolt. Holding as was at the moment @ 65nM but I don't want to tighten further in case it rips the thread.
Last edited by Terminator; May 16, 2008 at 01:54 AM.
, till the next rotor change 
. Then buy a upright and replace the whole mess.....best of luck....
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No dogs in this fight but if my regular mechanic were to have something break while making a repair, I would assume that it was caused by the repair and unavoidable. If, on the other hand, he damaged something that was not involved in the repair or through obvious careless workmanship, I would not expect to pay for the extra repair. When my regular guy works on it, I trust him totally. When someone I don't know is involved, I want to watch if there is anyway possible. Dealer's don't want you to watch, generally, and my regular guy will let me hold the light or whatever.
I thought I read in the manual (I only have the software version) that there was a step by step repair of the aluminum threads. I also thought they specifically sell a thread repair kit for this very reason...
That said, John H. and ViperBob both gave you very good opinions on how to handle this, but in all honesty 2MM of thread on that bolt is nothing to sneeze at. I'd torque it down properly and if it holds (after putting heat to it first, loosening it, then cleaning the threads or getting new bolts and retightening it with antisieze) I'd drive it... Those bolts have a LOT of thread they go thru in the upright.
As Derboost said, then you're good until the next brake job. At that point I'd order up some GT2 uprights and go BIG on the old brake category, since you'll want to replace that one, maybe!
Mike
That said, John H. and ViperBob both gave you very good opinions on how to handle this, but in all honesty 2MM of thread on that bolt is nothing to sneeze at. I'd torque it down properly and if it holds (after putting heat to it first, loosening it, then cleaning the threads or getting new bolts and retightening it with antisieze) I'd drive it... Those bolts have a LOT of thread they go thru in the upright.
As Derboost said, then you're good until the next brake job. At that point I'd order up some GT2 uprights and go BIG on the old brake category, since you'll want to replace that one, maybe!
Mike
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Remember that you need 1.5 times the thread diameter to torque correctly, ie, a 1/2 inch bolt needs 3/4 of a inch of thread.
Thread strength (Quote)
"Nut threads are designed to support the rated clamp load of their respective bolts. If tapped threads are used instead of a nut, then their strength needs to be calculated. Steel hardware into tapped steel threads require a depth of 1.5× thread diameter to support the full clamp load.
If an appropriate depth of threads are not available, or they are in a weaker material than the cap screw, then the clamp load (and torque) needs to be de-rated appropriately"
I believe the spec for Aluminum is 2.5x dia, but not sure
Thread strength (Quote)
"Nut threads are designed to support the rated clamp load of their respective bolts. If tapped threads are used instead of a nut, then their strength needs to be calculated. Steel hardware into tapped steel threads require a depth of 1.5× thread diameter to support the full clamp load.
If an appropriate depth of threads are not available, or they are in a weaker material than the cap screw, then the clamp load (and torque) needs to be de-rated appropriately"
I believe the spec for Aluminum is 2.5x dia, but not sure
