OOhh. Did you tap it with a brass hammer? It sounds like it's not seated properly. (well I hope thats all it is.) The grooved Code 3 is the original version. I can't imagine it needing so many shims unless you somehow got the worst Code 3 pulley on the planet. Mine was a huge disappointment with the dial caliper and feeler gauge, but works great. Good luck getting to the bottom of the problem.

Les