VR6 Helix clutch failed (x2!)

howdy all

i am at a complete loss as to why i've had two clutches fail on me - and helix items at that!

as i'm sure oyu all know; the pressure plate comes in two parts (one part that butts up against the friction plate and then the other which is the outer casing) and there are three metal straps that hold both parts together. these straps are riveted onto the outer plate.

for some bizzarre and unknown reason my car has destroyed one of these rivets on two separate VR6 helix clutches.

my car is only running 280-300bhp, the flywheel is now definitely fine and with no defects and there is nothing wrong with the gearbox either.
the car has had new clutch master and slave cylinders and a new braided line to connect the two. it's also had a new VAG release arm that drives the also new thrust bearing onto the pressure plate.
i really can't see why the car has destroyed two clutches like this. there are people out there with 100bhp more than me running the same clutch with no problems at all. i've also been very kind to both clutches while bedding them in (no racing starts etc), so i have no idea why this is happening. there's no evidence of anything fouling on anything else inside the bellhousing.

any helpful ideas would be appreciated.
as it is i've lost all patience with the car now, so i'll probably end up breaking it (which will certainly break my heart if nothing else!)
nonetheless, i'd still like to know why this is happening...
(i'm also going to speak to helix on the phone tomorrow and see if they can shed any light on the situation)

HELP PLEASE!!!


thanks very much,

Pete

Have you got any pictures?

The straps can flex to allow the pressure plate to release the friction plate right? I ought to dig out an old clutch I have at home...

You're running an Autotech alloy flywheel right? Has that got the same pegs as the VR flywheel for the pressure plate to locate on?

i haven't got a pic of either clutch i'm afraid an the second one is stilli the car (but it's making exactly the same rattly noise as the previous one at exactly the same point in travel of the pedal; right down on the floor).

basically the strap itself was totally intact and didn't appear to have suffered any damae at all - it was just the rivet that had sheared...


and yes - my autotech flywheel is an exact copy of the original VR flywheel, only in ally obviously

You using a standard VR gearbox mate? If so maybe try a standard clutch set up, I'm sure I read somewhere that the standard clutch is ok up to about 300bhp?

Is the Helix an R32 or VR6 clutch?

I personally think the best way to get your money back is to break the car..
People will be reluctant to pay what the car is worth with its current problem imho.

However it has to be worth one more stab at it.
I'd take the gearbox off and see if the damage is exactly the same as before,or if there are any other signs that may intimate what the problem is.

If your still pi$$ed at least you can carry on dismantling from there.
Crack it open take pics and get 2nd opiniond from there.
Sorry not much help but thats what i'd do as I have no idea why your car is eating good clutches.

Good luck.Hope it works out.

oh and as Mic said I discussed this today with ctwg60 and he said the same.You should try using a standard vr6 clutch.

cheers gents - did think about going back to the standard vr clutch as it's supposed to be able to handle the power.
the thing is though, it should be right on the power limit for the standard clutch and (so i thought...) helix are really the best there is when it comes to clutches - there's no way this should be happening with the kind of power i'm running.
also it's a right nause to take it apart and put it back together again potentially only to have the same thing happen again.
to be honest i'm just totally hacked off with the car now and i want something that i don't have to think about.
valuable lesson learned i feel - never modify your daily driver!

(for the record it's a vr box with a quaife and a longer 5th from a passat tdi. it's also running a vr6 flywheel, (albeit an aftermarket ally item) and vr6 helix clutch)


don't suppose anyone fancies swapping for a 3.2 audi a3?!??

If you want to try, just to see what happens, by the the weekend after next I'll have a used VR clutch, nothing wrong with it going spare.

Toad wrote:If you want to try, just to see what happens, by the the weekend after next I'll have a used VR clutch, nothing wrong with it going spare.

Yep, I've got a spare one somewhere as well. Plus if you can survive for a couple of weeks I'm happy to come to you and give you a hand swapping them over? (i'm away from this weekend until May 20th)

If this is your last remaining problem with it then it seems a massive shame just to jack it in for something else.

If it's shearing rivets and you're well within the power limit of the clutch then I'd say something is not fitting correctly causing something to catch.

Pete have you managed to find out if any of the other people who run that clutch get the same funny noise when the clutch pedal is to the floor? Might be worth investigating.

Also, did the people who did your box change the clutch release bearing? Can't remember whether you said it was all pukka in there.

mic_VR wrote:

Toad wrote:If you want to try, just to see what happens, by the the weekend after next I'll have a used VR clutch, nothing wrong with it going spare.

Yep, I've got a spare one somewhere as well. Plus if you can survive for a couple of weeks I'm happy to come to you and give you a hand swapping them over? (i'm away from this weekend until May 20th)

Oddunit meet at Pete's place???

Toad wrote:

mic_VR wrote:

Toad wrote:If you want to try, just to see what happens, by the the weekend after next I'll have a used VR clutch, nothing wrong with it going spare.

Yep, I've got a spare one somewhere as well. Plus if you can survive for a couple of weeks I'm happy to come to you and give you a hand swapping them over? (i'm away from this weekend until May 20th)

Oddunit meet at Pete's place???

Damn straight, lets get this thing sorted! All it needs is a little OU love

Hi Pete, I know we spoke on the phone this morning, but a few more thoughts.

The clutch plate assembly doesn't like radial mis-alignment. The straps allow the pressure plate to move a little along the input shaft for clutch release. The mis-alignment must be radial to break the rivets off, and it obviously isn't much or you'd feel in when taking up drive or even just driving down the road (like missing a wheel weight). Hence why you get a few miles out of the clutch and then it breaks a rivet through fatigue.

So my thoughts.....

Are the location dowels still fitted between the engine and gearbox?

Is the box mounted square to the engine block mounting face?

Is the release bearing returning fully home? If any load is still on the clutch the straps won't be straight and the rivets will be loaded in a direction they aren't designed for under continuous duty. The straps will always be trying to pull straight by the rotation of the clutch (centrifugal), if something stops this (like the release bearing) the rivets will again see more load than they should.

Either of these will cause excessive loading of the clutch straps / rivets and clutch failure.

All here to help Pete, don't give up.

WOW! Guess I was paying attention when AP Racing did a clutch training course for the company I used to work at

PS Car is awesome, all that NA power as soon as you open the loud pedal!

Yep, just what i was thinking. If the problem only occurs at the limit of the pedal travel, then something is moving too far and causing the rivet to shear off.

I hate to say it, but the box is going to have to come off to investigate and I would A) Use a standard Flywheel and B) a standard clutch. If the problem goes (and you'd hope it would after a 3rd attempt!) then it was a combination of flywheel / and or aftermarket clutch misalignment, or perish the thought, user error

It's worth noting that the pressure plate in the Helix kit is actually a Sachs Sporting part. Helix only make the friction linings. I've never heard of a Helix kit fail in this way. A bit of judder and slight marble can rattle, perhaps, but nothing like that!

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As above I think a lighter flywheel and stronger clutch maybe the issue. Standard flywheel and clutch setup will sort it as you have removed all the possible problem parts.

Modifying a daily driver that you need everyday is another ball game to just modifying a car. You have to cover all bases and really think about reliability not just ultimate power. But I guess your coming round to that idea.

I think what you've done is fine it's just been let down by aftermarket products. I always try to avoid aftermarket stuff it always gives you grief,an aftermarket schrick alloy sump gave me the most grief in my entire build and it will be sold when the gearbox comes off later in the year.

Here's a quote from the above thread...


"Well just an update on this!

The clutch was sent back to Helix for testing, They got back to me saying the clutch had failed due to it being dropped off the line (drag type start)
Apparantly this can cause the clutch to fail, even thou the 4 point paddle clutch is rated to 300Bhp / 320 Ft lb's

So basically you carn't even do one high rpm start off the line, I thought Helix made competition / race type clutch's

Well I can 110% confirm that never happened, I couldn't do that even if I tried due to all the traction issue's
The only way that would work and the tyres grip would be in 3rd gear in perfectly dry conditions.

If I even attempted that in 1st or 2nd in any road condition, the tyres just instantly spin up and loose traction. This is already a problem and regular issue with normal driving.
Now I would have thought if the tyres just loose all traction and spin up, I wouldn't have any resistance/friction from the road surface & tyres putting preasure on the transmission?

What do you guys think?.

Anyway, Helix modified the clutch and changed the springs etc. to cope better with the torgue/power output, which has made a massive difference to the car.
Fair play to Helix in the end, at least they tried to sort the problem, if it works only time will tell.

Altough still not entirely happy it went in the first place, wonder if the mapping abuse caused the problem??

Everything that could be checked was checked and proved perfectly fine Gearbox, flywheel etc etc."

Firstly, welcome along Pete!

Secondly, are we gonna have another OddUnit Engineering Triage?

Any updates Pete?

howdy gents, thanks very much for all the input - reall appreciated.

apologies i haven't replied on here for a while; been away for a few days with work.

i'm still undecided as to exactlywhat i'm going to do with the car yet. the way t's looking at the moment though, i think i will end up breaking it...

If your going to break it it must be more than just the clutch your unhappy about. Are you dissatisfied with the end result regardless of the clutch issue or was it the trauma of the install that has ruined it for you?

i'm not disappointed with the end result (despite the fact the suspension etc still needs setting up properly, it felt really good to drive). there are a load of issues to work out still if i was to keep it (changing the enine mounts or something more sensible, having a major sort out of the interior trim, paintwork, very slight blow in the manifold etc etc).

the thing is i've just totally lost all motvation with the car. also if i fix it now, there's nothing to say it won't just break down again before long and frankly i'm pretty f*cked off with it all.

i really need a reliable car for my daily; one that i know will give me no problems at all, will start first time every time and won't break down during a journey. that's largely in part because of my job, but also the inconvenience that having a car like that causes, not to mention the fact that both my parents and my girlfriend now hate cars more than anything else in the world!

to be honest i'm properly gutted to pull it all to bits, especially after all the effort that's gone into it; but it's obvious i can't rely on it and i really am just fed up with it after it's taken so long, so much effort and caused so much heartache at home - enough is enough

It is a shame,but I see where u are coming from.

The thing that costs the most money with any daily driver project is reliability. It's an age old problem unfortunately.

Typical example, do you use cheap silicon vacuum lines that can split and pull off the fittings easily, or do you spend 50 times as much on proper braided lines and fittings that will last indefinitely?

My view is "If there is any doubt, there is no doubt". Any part that doesn't look quite right or looks flimsy, WILL let you down sooner or later and leave you stuck by the side of the road. It's all part of the school of over engineering.

I learned that mistake with the crappy Brazilian manifolds and cheap rubber hoses etc. They DID let me down.... repeatedly.

I suspect if you'd gone the whole hog and fitted the matching 02M gearbox and clutch to go with the r32, you'd be absolutely loving it right now. But it boils down to money and time, which is another hurdle with most projects.

Anyway, I think it's totally salvagable. Some of the stuff you've listed is very minor and can be done as and when.

You've got a good engine in the car which will last you, the rest can wait until your enthusiasm returns. I really wouldn't sell yourself short mate, you should be proud of what you've achieved. I certainly couldn't wave goodbye to 6 years hard work.

Chin up! Have a mull over the weekend and see how you feel

Hi Pete, well my hour long lecture as to why you shouldn't sell it didn't work!!! Still when you pull the box off just check the input shaft.

Another 24V that hasent been kept after the conversion, are they all destined to sell after the conversion is complete? I have the week off this week and was intending to go up to Jon's workshop to bolt on the rest of the suspension/brakes lines etc, now I'm wondering

on a random and belated note...

i finally got round to taking the clutch that i didn't buy new to a friend of mine who works at LuK clutches.

he had a look at it and said that he doesn't recon that the rivets wee installed squarely - baically that means that they wll allow a tiny bits of movement in the check straps which will eventually translate into a lot of movement which will saw it's wat through the rivets - not good!

i still recon that my flywheel or some part of my car was at fault rather than the helix, but it's interesting to hear his opinion.
he's going to replace all the rivets for me, test the clutch of their macine then give it back to me; so if anyone is in the market for a basically new vr6 helix clutch at a much reduced price then please drop me a PM