Welding timing pin on flywheel

[Error404]

can i do it?
while the flywheels in my hands, thought about a quick zap with the mig just to make sure the ****er doesn't fall out anytime.... any reasons why i shouldn't do this?

Cheers
Alex

[driftin jo]

can i do it?
while the flywheels in my hands, thought about a quick zap with the mig just to make sure the ****er doesn't fall out anytime.... any reasons why i shouldn't do this?

Cheers
Alex

Pin is hardened steel, the flywheel is cast iron , not clever to try and weld the two. also the heat may cause the pin to stress fracture, then at 7000 rpm snap off.

[quattro]

Not really a load bearing joint is it (weight of pin not even 20g) dont think it would fail with a small weld on it, but I would not mig it as the steel are different.

[Error404]

Thanks guys, I won't bother then as the TIG gear I borrow is miles away and I want to refit the flywheel tonight... hope i don't regret it!

[quattro]

I'd say glue it with araldite or something like that, but i think the long term vibration will just crack the glue....

[driftin jo]

Not really a load bearing joint is it (weight of pin not even 20g) dont think it would fail with a small weld on it, but I would not mig it as the steel are different.

If the pin is 10 grams it will have centrifugal acceleration of about 8kg on it at 7000rpm

[Error404]

the pin is fine as it is, not got a problem with it just didn't want to put the car back together and 3 weeks later the pins gone walkabout.. it'll be ok i'm sure

[Acidburn]

it'll be ok i'm sure

famous last words....

[driftin jo]

the pin is fine as it is, not got a problem with it just didn't want to put the car back together and 3 weeks later the pins gone walkabout.. it'll be ok i'm sure

yes I wouldn't worry about it , I know some people have had the pin come out but I think compared to how many there are in service that it is a very rare occurrence . It must be due to a manufacturing defect , the hole being too big or the pin undersize when assembled .
I have converted flywheels and fitted timing pins and there is no way any one I have fitted would ever fall out , very tight fit.
I have also drilled flywheels from the back to facilitate removing pins from the front so I could re skim the face . The pins take quite a good hammering to come out showing that the standard Audi interference fit is nice and tight.

[Ruffiano]

For what it is worth, I lost a timing pin on my flywheel, I removed the starter and welded a new pin in place, worked without a hitch.

[A80Avant]

for vems on the 7A flywheel we had to enlarge and strengthen the pin because the ECU wasnt able to pick up the signal. So from being a small round cylinder we made it bigger and flatter so that VEMS can now see it. I cannot see or notice and problems with imbalance on high revs or anything like that with the few extra grams of steel that was welded there. Maybe there is, but its not noticable. If we didnt do that, VEMS wouldnt work.

Having said that, its likely that i will go back to the OEM flywheel though, as i feel that it can cope with 620Nm of torque fine and has much smoother ride.

[quattro]

If the pin is 10 grams it will have centrifugal acceleration of about 8kg on it at 7000rpm

I get your point but 8kg aint exactly a lot for a good weld now is it........

[DJones]

I would leave it alone, the weld would add weight in the wrong place with respect to balancing.

[driftin jo]

I get your point but 8kg aint exactly a lot for a good weld now is it........

As I said in an earlier post the pin is case hardened and the heat from the weld may cause the pin to stress fracture , then you add the 8kg on to it and it could cause it to snap .I'm not saying the weld would not hold it at all just that you may stress the pin welding it.

[Jamo]

Don't weld a pin weld a piece of magnetic material onto it, that's how mine is done