what a discovery !!!!!

[Keith]

look at what I just found this afternoon :

[Animal Mother]

Oooh. That was close.

[Keith]

Oooh. That was close.

I wasn't looking for that I just saw it before remount !!!!

I could have not seen it !!!

the engine would have broken a few days after !!!!

oooops...............

[Pirvu Eugen]

You are verrryyy lucky!!!
Good that you find that in time!!

[S-Express]

Ok so the key is sheared - BUT if you had actually managed to bolt up the pulley to the correct torque with a new bolt etc - that damaged woodruff key would hold fine.
You don't honestly belive that all the engine's torque is transferred through a 5mm thick peice of sintered alloy do you?
I put my crank pulley back with a similar (though not as large) crack about 7k miles ago, safe in the knowledge that because the pulley was done up to the correct torque with a new bolt, then the key will hold fast - the compression of the pulley onto the crank gives such massive frictional properties - that key will not break.
Why do you think Yamaha/Duratec engines don't even have a key. (neither do zetec cam pulleys for that matter).
Sorry about the little rant - but I needed to set the record straight....
Now I'm off to hide..........

[volcano rs]

Ok so the key is sheared - BUT if you had actually managed to bolt up the pulley to the correct torque with a new bolt etc - that damaged woodruff key would hold fine.
You don't honestly belive that all the engine's torque is transferred through a 5mm thick peice of sintered alloy do you?
I put my crank pulley back with a similar (though not as large) crack about 7k miles ago, safe in the knowledge that because the pulley was done up to the correct torque with a new bolt, then the key will hold fast - the compression of the pulley onto the crank gives such massive frictional properties - that key will not break.
Why do you think Yamaha/Duratec engines don't even have a key. (neither do zetec cam pulleys for that matter).
Sorry about the little rant - but I needed to set the record straight....
Now I'm off to hide..........

too much of a gamble .i've been there with 10 bent valves and a snapped timing belt

[S-Express]

yes you're right - it is.
BUT I just wanted this common misconseption quashed !

[Keith]

Ok so the key is sheared - BUT if you had actually managed to bolt up the pulley to the correct torque with a new bolt etc - that damaged woodruff key would hold fine.
You don't honestly belive that all the engine's torque is transferred through a 5mm thick peice of sintered alloy do you?
I put my crank pulley back with a similar (though not as large) crack about 7k miles ago, safe in the knowledge that because the pulley was done up to the correct torque with a new bolt, then the key will hold fast - the compression of the pulley onto the crank gives such massive frictional properties - that key will not break.
Why do you think Yamaha/Duratec engines don't even have a key. (neither do zetec cam pulleys for that matter).
Sorry about the little rant - but I needed to set the record straight....
Now I'm off to hide..........

Every thing's tightened to the correct torque, I Know what I'm doing....

still didin't find how it happened

[newsh]

My theory is it happens when you tighten it, the nut moves the pulley round and breaks the key as you torque it up, this means if you use it again it might break completely while tightening and end up correctly torqued but in the wrong position.

[Keith]

My theory is it happens when you tighten it, the nut moves the pulley round and breaks the key as you torque it up, this means if you use it again it might break completely while tightening and end up correctly torqued but in the wrong position.

you mean you would change it every time you change your timing belt ?

[Jamo]

Ok so the key is sheared - BUT if you had actually managed to bolt up the pulley to the correct torque with a new bolt etc - that damaged woodruff key would hold fine.
You don't honestly belive that all the engine's torque is transferred through a 5mm thick peice of sintered alloy do you?
I put my crank pulley back with a similar (though not as large) crack about 7k miles ago, safe in the knowledge that because the pulley was done up to the correct torque with a new bolt, then the key will hold fast - the compression of the pulley onto the crank gives such massive frictional properties - that key will not break.
Why do you think Yamaha/Duratec engines don't even have a key. (neither do zetec cam pulleys for that matter).
Sorry about the little rant - but I needed to set the record straight....
Now I'm off to hide..........

The woodruff key breaks the crank still rotates but the cambelt does not as it is driven off the crank pulley which will be slipping, the valves therefore aren't closed in time and the pistons smash into them bending them.

Impossible scenario? Check the forum or ask Phil2.016v this is what happened to his Avant

The torque isn't the issue, the non rotation of the crank pulley in time is!

[S2central.net]

Its little money for a lot of confidence...

[Jamo]

you mean you would change it every time you change your timing belt ?

This is what Vagparts advise their customers and Martyn has a thread on here to that extent.

It should be treated as a service item.

[newsh]

you mean you would change it every time you change your timing belt ?

Yup

[Keith]

The woodruff key breaks the crank still rotates but the cambelt does not as it is driven off the crank pulley which will be slipping, the valves therefore aren't closed in time and the pistons smash into them bending them.

Impossible scenario?

I Know about it, that's the reason why I posted this image.... so people can see what can happen even when work is well done !!!!!

I think I will now change it everytime !!!!