Funny, AM had a worldwide recall of the vantages after late '07 due to the counterfit plastic used in the accelerator pedal mechanism. they found out it was a problem, and stood behind the fix. yet, they know of the clutch disc coming apart, yet no recall? is that because the failure isn't life threatening? either way, its wrong. if rivets are coming out of a disc plate, and its a known issue, there should be a recall.

 

Yes. I don't know if I'm just not getting through:

1) The clutch failure is not a safety-related recall issue. This is what Service Bulletins exist for.

2) You have no idea if this issue is really widespread or just a few cases here and there. It's not like people come onto a forum to let you know that their clutch is still working well. Again, the Internet magnifies issues. Do you know how many clutches Aston has put into cars and how many have actually failed due to rivets coming apart? No, of course you don't. And neither do I.

In fact, I don't even recall reading of that many people on here saying they have had this issue. Maybe 2 or possibly 3? I don't know where you are getting the idea that this is a serious, recurring issue. There have been hundreds of clutches installed in Astons and yet you suggest replacing each and every one under some non-safety-related recall because you read on the Internet that a couple of guys had theirs fail due to rivets? Come on!

3) A clutch is more likely to fail, as you have mentioned numerous times, because someone abuses it. It is considered a wear and tear item. So, when a car is under warranty and it is brought in for a new clutch, if the tech determines that the failure was not due to wear but rather to a faulty component, a warranty claim is filed and Aston pays for the repair. This is the way the process works. Why should Aston spend money to replace perfectly good clutches or clutches that are worn because some people don't know how to drive a manual properly?

 

007, with a hydraulic slave cylinder like the ones used on our cars, it isn't suggested to resurface the flywheel. There is limited movement with the throwout bearing assembly and the deflection required to move the springs on the pressure plate the appropriate amount for engagement, and disengagement is critical. If you remove .001" from the flywheel surface, then you should also add a shim of the same amount to the throwout bearing to compensate. My flywheel was glazed a bit, as was the pressure plate, however they were not burned, scorched or discolored. The clutch had just started to show signs of slippage under load in 5th and 6th gear, so I replaced the disc.
As for the rivets on Valeo discs not being a Valeo problem, you guys may not have much experience working on track and racing cars. The Valeo units are very cheaply made in other aftermarket apps and with the numbers of cars I have worked on, I stand behind my statements along with those mechanics I have worked with. Experience is a fickle teacher. I was surprised to see that Aston used Valeo branded products in the clutch. You can agree or disagree with my statements, however, I have plenty of first hand experience with the assemblies and regardless of the drivers "techniques", I have replaced those Valeo units with anything from Spec clutches, Daikin clutches, ACT clutches and have had 0 issues with faulty assemblies or failing rivets period! When working on cars designed to be beaten on, that speaks volumes in experience, not conjecture and speculation.

 

Thanks for the input Art, I will take your word for it any day over speculation by forum armchair engineers. True experience is the best teacher of all, I agree 100%.

 

being realaltively new to the group, I was just going off what has been posted. it looked like there was a serious premature failure issue in the AMv8 clutch. Absolutely , it could be due to abuse or mis-use, as you agreed. And if the rivets coming apart on the disc pack was only an isolated event, then sure, AM wouldn't be involved with that, unless it was a known issue with the Valeo clutches (as someone pointed out there was a lot range that was known to be bad. this might just be a rumor though) I think if there are those here that understand the characteristics of the clutch, and treat it like a racing clutch. (high clamping force, softer clutch disc material) then, the clutches should last a very long time. if you sit at stop lights with the pedal in.... rev the engine high and release, blame the tall gearing for inability to reverse up hills, then the clutch will fry and will need to be replaced prematurely..... its that simple. However, if clutch disc rivets are falling apart, then that's another issue.....

 

Well, even though I was surprised at the Valeo unit in the car, I replaced the clutch disc before the rivets were a problem. My disc was badly worn down, but it appears as it is simply from 55K miles of use, and not abuse. I have driven the car easily since I have owned it, aside from a few hard pulls in 5th gear on a dyno, the car has been driven carefully. Luckily the rivets are completely intact and the installation of the replacement disc went without a problem. I have broken in the new disc for about 550 miles now, but I have yet to really push the car since breaking it in this past weekend. I drove lots of mountainous roads in northern Arkansas without any slippage and the car pulled up long hills with the cruise on in 5th and 6th gear without slipping as it did prior. Thanks Stuart, I will be scheduling the dyno session for the end of this week or early next to test out the chip/tunes we loaded onto my laptop.
Art

 

It is abuse to have a clutch disc wear out at 50k miles. there is really no wear on a clutch if driven correctly. as I mentioned, I had a sachs clutch last over 50k miles and 10 years of hard core racing . The discs are still in the car. if the pressure plate has enough force, there is no slipping in gear. dyno all day long, there should be no slip, and thus no wear. The only wear you can have on a clutch is releasing it too slow on acceleration from stop, or mismatching engine vs gear speed on shifts. (i.e. speed shifting, you know, flooring it, push clutch in and change gears, let clutch out as rpm GETS near redline.) All the wear will come from this. Its the ONLY way the clutch discs can wear. You may think you are driving easy, but your release technique, as well as possibly keeping your clutch engaged at stop lights or in traffic, could have contributed to premature wear. also, just because the discs are worn, doesn't make the clutch slip, for the small reduction in pressure due to wear. however, glazing of the flywheel can do this, as well as contamination. Or, in extreme cases, the pressure plate can be exercised too much and have its spring pressure reduced. (spring fatigue

As I mentioned. when you have a high force clutch pressure plate, and you have relatively soft clutch discs, you cant drive it like your high school VW or Honda. you can smoke the clutch really easily.
Again, driving hard or dyno'ing 'til the cows come home, wont effect your clutch at all. there is NO break in period for a clutch. just use it properly from day one and you are good to go.


)

 

My Pleasure Art!!! Looks like your friend's battery arrived today as well.

 

I am not here to have a war about clutches and wear items on a vehicle. Do a bit of research on how a clutch, more specifically a single plate, single disc clutch works and you will see that it functions much like a set of brake pads. There is NO way Humanly possible to match the speed of the pressure plate, flywheel and FRICTION disc of the clutch on every single shift and motion of the car. Especially when starting from a stop. The wheels are not turning, the engine is running and you have to propel 3500 lbs of vehicle forward. You are going to have slippage just from engaging the clutch against the flywheel when you release the clutch pedal. Just because the pressure plate has alot of pressure does not mean the clutch won't wear. When you press the clutch pedal in, that pressure plate releases the pressure on the plate and the disc spins and disengages from the pressure plate. When you release the pedal, the pressure plate now moves closer to the disc again and since the disc is attached to the drive shaft and the pressure plate is attached to the engine/flywheel, they move at different rates now, until they make contact and catch up to one another. The clutch is a wear item because it wears out. 50K miles may be premature, yes, however, there are far more that wear much sooner, and yes, the operator has much to do with it, however, the clutch disc is designed to grab and hold the pieces in unison when shifting, however, when upshifting and downshifting there is always going to be some slipping. PERIOD! That is why bellhousings have a vent and some of them even have a filter to catch the disc dust that comes from the friction. In a vacuum, with a computer dictating exact engagement times, speeds and rpms it can be done with very little wear, but every time there is a depression of the clutch pedal, and a release of that pedal, the disc is spinning at a different speed than the other components, and therefore you will have wear. A twin plate disc setup is far different as far as wear goes. There are 2 plates and 2 discs and therefore the wear is divided among these surfaces therefore making a true twin disc racing clutch last far longer. An additional benefit is the friction is divided and spread out more evenly and absorbs more heat, also aiding in the wear characteristics. A single disc, single pressure plate system is simpler, and cheaper, but usually requires more pedal effort and therefore more heat ends up being built into the system along with faster wear. Find me a clutch that is covered under a warranty besides a defect. You won't because they are designed to wear out eventually and be replaced. If they didn't wear out, like you suggest, then they would be covered under the drivetrain warranty of every manufacturer. None warranty the clutch. Period.

 

Got the battery Stuart! Heading over tomorrow to install it for him along with the new hatch struts! A regular Aston Martin service day!

 

Not a clutch debate or war, just providing some useful information. take it or leave it.
You have a close to accuate theory of clutch operation, but what you fail to recognize is that the clutch, when released, almost synchs up with the flywheel instantaneously, meaning, there is little wear. Any heat, is well with in the materials capabilities. there is also plenty of time for it to cool before the next shift. The only time you get wear, is 1st/R gear release, and if done properly, its minor. less than 1-2 Hp to get the car rolling before a full release. 2-4 750watt/seconds and then NO friction or heat generated. It takes so little force to get a car moving, especially with the gear advantage of the AMV8 1st gear. at near 12:1 , you almost don't even need to rev the car at all to get started. this means, very little force at the clutch and clutch disc, so very little wear. and, if you do want a jack rabbit start, just dump the clutch and apply the throttle.... is that simple. smooth, fast acceleration, without much wear.

So, the clutch is a wear item by design, but, if treated with some knowledge, it can last almost as long as the car. In fact, you should see throw out bearings or pressure plates fail first due to cycle fatigue or wear. However, if abused, you will see it wear out 20-50k miles. as well as other components failing as well.
This picture below is a stock clutch disc used in a racing application, on a car with 50,000 miles, and 130race hours . (on a race car with near 400 rear wheel hp). HOWEVER, its a factory stock street clutch disc.. nothing fancy. no mods, just a higher pressure , pressure plate.
Notice that you can still see the print on the actual disc's surface!!!!! , even after 10 years!!!)
why? Ill tell you why........ quick release starts without reving the engine way up and releasing. Hard and fast release at redline shifts, and near matched RPM downshifts, again with quick release of the clutch.


your proof in that they are a wear item , due to the manufacturer not warrantying them is pretty weak. They don't do that for brake pads, yet I have a chevy Tahoe with 130,000miles on it now, and the pads are only half gone. (race car tow, no trailer brakes, use it for work. lots of stop and go driving, and I'm not easy on the truck either. ) yes, all moving parts will wear out, just a matter of when. soon or later. some of the "sooner" is due to operator error, and the manufacturers protect themselves from that by only insuring the moving parts that cant be abused or hurt by operator error.

The problem is a lot of folks think its cool sounding to rev the engine and relase the clutch slow, or think in reverse, you need some really high RPM release to get the car to climb a hill. This is not your grandpa's VW bug.

 

Art is right in this debate. Besides... In order to get 50k+ miles out of the stock clutch you have to drive it so gingerly it defeats the whole damn purpose. You might as while buy a honda civic.

Furthermore, aftermarket clutch discs can handle stupid amounts of pressure and abuse without having the rivets & err break/fail/come apart. Using aggressive driving as an excuse is just covering up for inherent flaws in products design. The stock cltuch is notoriously weak, that's just a fact. Most aston owners do not drive aggressively and they still has an abnormally high failure rate.

Moral of the story: stock clutch is weak, WHEN it fails just upgrade to the superior Velocity (or other equivalent) aftermarket friction plate

 

Stuart, both you and Art have some points, but far from right here.

I don't think we can consider, aggressive driving, with poor release habits, synonymous . Ill take this aston to the track every day for the end of its useful life and the clutch will not be the first thing that breaks or wears out....believe me! On the street, ill melt the tires on every stop light release, and redline every shift and the clutch discs will be fine. Now, if my theory of the clutch pressure plate being at a high force level, is not correct, then you will get slip and on max acceleration rates, you will get slip , and tremendous wear. I don't think this is the issue. so, im just providing possible cures for premature wear from a use technique perspective.


Now, should you be able to do high rpm releases , and rev the engine while you feather the clutch in reverse to let the folks know behind you, that you are backing up as you make a boat load of engine noise???? absolutely. So, yes, if I was going to replace the clutch, going by what I have heard, I would use the aftermarket set up you tout. But, anyone driving a stick car, incorrectly over a few years, can burn a clutch....... as was said, it is a wear component. But if treated correctly, I don't see why it cant last the life of these cars by not driving slower, or less aggressively, but just with some care and thought. aggressive driving has nothing to do with clutch wear. after all, if you just dump the clutch on every shift, (especially the 1st gear start) there will be nothing moving very much to wear!!! (do I need to post an AMV8 shift technique instructional video?)

 

I had the defective clutch issue in my 08. The clutch came apart and Aston replaced it. This issue is old news and Aston took care of the cars that had the bad discs. There have not been any issues or service bull items since.
X: The clutch is a wear item and is not covered under warranty for the very good reason people tend to abuse them. It is not reasonable to expect a clutch to last 100,000 miles or the life of any car because of a wide range of circumstances.
We don't need you to provide an instructional video or to keep repeating your opinion ad nauseaum. It seems as though you can't stand it if anyone disagrees with anything you say.
You are not the worlds expert on all things automotive. Get over yourself.

 

What im talking about here, is not an expert opinion. its basic common sense. Its the opinions that are coming back, im providing some facts. Clutches don't wear by aggressive driving, or on dynos, and clutches don't need to be broken in. Im trying to help those that are driving the car like im describing to get more life out of the clutch. saying that drivng hard, will wear a clutch out, is just not true. I have no problem with someone disagreeing, but if you are going to disagree, you should provide some proof or logic and expect that to be discussed. can anyone explain how I can race for 120 hours, and 50,000 miles on a stock clutch (of a different car but sill to make a point) and still see the writing on the clutch discs??
Some people get so defensive when they might be to blame for mechanical failures, because, they couldn't possibly be responsible for anything failing on a $130k car.
Hey, its just a bunch of experience here talking, and trying to help. take it or leave it. its a discussion .... nothing more nothing less. ignor me, if you don't want to discuss. no need to get rude.