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So on a moderately powered car, say approximately 200hp from a common 3.0L, would this addition increase the life of the guibo over time, or just keep it from failing as soon with higher horsepower applications ?
Thanks,
Merril

I dont see how it could hurt. that shaft spins really fast even if your car doesnt have big hp. 100rps is serious inertia and those donuts are not free. Even if it increases the lifespan of the donut only a little it should be worth installing this innexpensive piece.
That is how I am looking at it.
Oh, and Merrill I wouldnt mind if I had your ¨low horsepower¨ engine in my car
James

I believe there is a commercial product made for this purpose. Now if I can just gets the pics up..

I think this is the link:

http://membres.lycos.fr/scuderiabiscion ... ts%202.htm

JJ,

I am still at a loss to under stand the purpose of this mod.

You say: "You can see that the bolts that come out of the flywheel go into rubber and then stop with just a nut on the other end and nothing holding their tips aligned (other than the rubber) They have the ability to flare under torque and at higher rpm the ends spread - this is what tears up the front donut."

How can this be? I've been scratching my head on this 1 for 2 days now. I still can't fathom how the bolts can flare. They are all held radially by the internal spider.

The donut broke on me with 225 miles to go thru mostly mountains. No sudden throttle movement and kept the revs to <3K RPM. She survived. Barely, I suspect.

Dat's a great picture. I suppose those lugs linked together by the 3-prong spider is not likely to flare...it's the other 3 lugs that are apparelty held together by rubber in a floating manner. Quite apparent from the rubber cracks developed at the flanges of the spider.

Curious how long does the front guibo lasts? My last piece was good for some 50,000kms...

Ciao
Vince

Believe me the three bolts will deflect.
Only I don't know what is worse, the engine torque or the rpm.



The rubber bits have a real hard life, between the bolts they are buckled by the torque and forced to fly out by the rpm.

Also the complete cage shown in MD picture will keep the bits together, maybe even enough to get you home after failure.

Carel

Hey Vince,

My rear doughnut lasted 12 months/ 15,000 Km

Naturally the spider cage bolts don't flare... It is the other 3 that we want to hold togther...

The commercial cage piece does not support it - the holes are large and allow movement if you ask me... I seem to recal that-that piece was a limp-home solution and also a safty addition to keep the thing from shattering and causing damage like it did for some of the others here... (Holes in exhausts etc...)

junglejustice wrote:Naturally the spider cage bolts don't flare... It is the other 3 that we want to hold togther...

The commercial cage piece does not support it - the holes are large and allow movement if you ask me... I seem to recal that-that piece was a limp-home solution and also a safty addition to keep the thing from shattering and causing damage like it did for some of the others here... (Holes in exhausts etc...)

The purpose of the cage is to contain the rubber. Let me think . . . which will flare more, the rubber or the grade 10.9 bolts? Seriously, if there was any significant bending of the bolts, they would be permanently bent.

The cage will contain the rubber if it fails . . . maintaining a semblance of balance so the driveshaft doesn't come through the floor (and on a 105 car it will). It also limits the amount of expansion of the rubber, reducing the tensile stress on it so it's less likely to fail.

Hi JJ

The three open holes are alined to the centre spider, the three small holes are the ones connected to the floating bolts, works exactly like yours in terms of the bolts, with the added bonus of stopping the rubber chunks flying in all directions.

But for a cost effective solution, can't beat what you did on yours.

Barry did it too and posted it on the old site http://www.alfagtv6.com/discus/messages ... 20010256pm

Carel

Yeah, hey, whatever works... Does anbody still make and sell those boxes...?

There's flaring of the bolt-tips at the outer edge and then there is also twisting in relationship to each other... I see the box holding the flaring bolts and rubber together; I don't see this particular design keeping the bolts from twisting in relationship to each other (holes have play...) Am I looking at the wrong holes - the ovals?

Then again, I was alwys a bit dense when it came to visual effects...

JJ

The oval holes are for the fixed spider. The other three small holes are for the floating bolt tips

Carel

Carel, you beat me off the line with that link to the old forum

What a ridiculus piece of engineering are those donuts... I would expect alfa to come back with a revised design like they did with the cambelt tensioner. But again... they made the things worse according to many

I think JJ ia rightfully confused because if you look carefully at the photo the holes of the alu-case are "wrongly" aligned. The oval holes are NOT aligned with those of the spider. Now... did they make a mistake when they took the photo or they run it like that?

Anyhow this is a great solution for either road or track since it cures the flexing of the bolts and also provides extra safety by containing the rubber in case of a failure. Next time I do the donuts they are going in for sure.

I also think that the donuts are very exposed (heat mainly). Especially the front and the rear. Tha rear can also get wet and be hit by stones from the road etc. I think it is a good idea, either with the cage or not, to put some rubber treatment on the donuts (not chocolate syrup!!!) to help them with drying, cracking etc. Even grease or waxoil might do

JJ the guys at the link further above are still doing them. I think there are a couple of other sources too but I can't recall them right now.

Guys,

Yesterday I saw my friend's 115 GTV's donut blow up. It destroyed the spider/yoke. Totally skewed. Wow! I never thought the thick spider/yoke would bend. My mechanic warned me about it but I always thought he was exaggerating.....

And that was on a 105/115 which driveshaft spins slower than a transaxle car....