Crank and Sprockets

[ein bora]

When I took my donor azz apart I paid particular attention to see if it had the updated sprocket on the crank, when it didn't - I order the tdi one and didn't think give it a second thought until today when the tdi sprocket came in.
Low and behold my crank has the two versions already cut into it. Nice surprise but is this normal. The second picture with the sprockets shows the old style on the left which came on the crank. Sorry for the poor first pic, but you can still get the idea.

[fatmobile]

A flat spot right on top of the old keyway.
 I wonder how strong that is?

[Thezorn]

all cranks have that flat spot in them from factory.

A flat spot right on top of the old keyway.
 I wonder how strong that is?

That is exacltly why it isnt used. If you are doing to upgrade, you'll want it to last. Pay a machine shop to do it on the opposing side as the stock key way. They will fill the old keyway and true up the crank nose after. Its worth it.

Does the TDI spocket actually fit snug on the crank as it is? I remember thinking that but I never checked to see if it fit.

[blackbird82]

Mine was like that as well. My 94 AAZ

but honestly I am putting my second TDI sprocket on soon

due to the alternator!  I did the clutched alternator, but not after driving on the new TDI sprocket for 100,000k

I gurantee you it will be worn, cause when I first go the car I did a t-belt and checked and it was already the TDI, machined onto the opposing side from the original keyway, and it was worn. literally the tdi sprocket was worn.

The alternator upgrade saves lives.

[Thezorn]

Mine was like that as well. My 94 AAZ

but honestly I am putting my second TDI sprocket on soon

due to the alternator!  I did the clutched alternator, but not after driving on the new TDI sprocket for 100,000k

I gurantee you it will be worn, cause when I first go the car I did a t-belt and checked and it was already the TDI, machined onto the opposing side from the original keyway, and it was worn. literally the tdi sprocket was worn.

The alternator upgrade saves lives.

Forgot to mention that. Its a must have upgrade for sure

[ein bora]

A flat spot right on top of the old keyway.
 I wonder how strong that is?

Why couldn't you just weld up the old notch and hand file the weld to match the tdi notch?

[Thezorn]

A flat spot right on top of the old keyway.
 I wonder how strong that is?

Why couldn't you just weld up the old notch and hand file the weld to match the tdi notch?

You could always do that, but the sprockets are ment to fit onto the crank with a .003" press fit and that would be pretty hard to do by hand.
If that sprocket is even the a tiny bit loose it will wear itself off the crank in no time.
I would personally never do that, a machine shop with charge you 1-2 hours max to do it right. Worth it in my opinion.