the flex plate is broke all the way around the center !!!

going to try the harmonic balancer it seems to be a little sloppy. well that's another strike know such luck.

2000 mercury cougar 2.5 when you turn a/c on loud knocking noise! thought it had a timing chain slapping. have now changed timing chains & tensioners, belt, belt tensioner, idler tensioner, a/c compresor & power steering pump have no ideas can some one help?