Crank timing belt sprocket i5

[QuattroBird]

Hi. Is there a recommendation that the crank timing sprocket with the integrated key should be changed at a specific mileage when the timing belt is changed. I hear some start to crack at the integrated key and want to avoid any such catastrophe that would ensue.
Ur quattro RR so assume similar to all UR’s S2 and RS2’s etc

If so genuine replacement best or improved aftermarket part?

[tractor Dave]

Yes, replace the crank pulley, they do shear. Get a billet one. Terrybullone on the S2 forum does a very good one.

My top pulley sheared on the S2 and I was very lucky there was no damage. I think it broke because it wasn't torqued properly during the 're build. The key is just to locate it. The large washer holds it tight and does all the work.
You can get a new top pulley on Audi Tradition for €60. I wouldn't go aftermarket for that part.
You also need to tighten it with a support tool so you don't put stress on the key. I made my own, copied from the tool used in the Haynes manual.
If it hasn't been disturbed, it's probably find for another 30 years.

[QuattroBird]

Thanks TractorDave. I am doing most things but for the TB I will draft in some knowledge but will get everything ready ahead. Worth it for piece of mind.
Thanks for the heads up will sort a billet pulley.