Update. Spoke with Canon on 1/7/14. Per the engineers - 'the noise did not occur under normal operating circumstances nor was the squeak able to be recorded on any audio equipment.' Lens will be shipped back with a smile from VA.
My last recourse would be to record some audio of the squeak on my 5D3 and send it back in yet again - but for what? This would be its 5th trip in if I'm remembering correctly!
I give up - Canon has wore me down. Tired of the constant back and forth and being down a lens. I'll just take a hit and sell old squeaky…It almost lasted a year haha! Im seeing Zeiss in my future. Very dissatisfied with all things Canon, but looking forward to the great things I've been hearing about Zeiss.
I miss manual focus primes... I know they won't squeak
Thanks for following my story friends and I hope you have better luck than I!