What's the word? I'm betting on the input shaft bearing secondly the pilot bearing. 
Dang we were betting ? I FOLD !!!! LOL
L50-52 trans are known to have input bearing failure. I have an L52 in my 82 which replaced the L50 with a bad input bearing. The L52 is doing the exact same thing as the L50 did in mine and that is exactly what he is describing. I am getting use to it making noise but imo its still the pilot bearing on mine. I am just to lazy to pull the tranny back to change it. Some time next week I will and then I will have my answer which should answer his.
OK OK I bet 5 trillion on Bill Clinton.
