i just got this 84 3/4 ton scottsdale. it sat since 2000. i did some tunning and all was well until one day it started clanking, not knocking and it really only did it when it was cold or untill the tranny fluid started circulating then it would quit. then it just got worse, but i could tell that it was coming from around the flywheel dust cover. so i pulled it off and you could see grooves from were the flywheel was hitting it so i thought the flywheel was cracked. when it warmed up and drove it quit, the knocking stopped. but it is doing it agian. you can watch the flywheel and the converter flopping/wobbling back and forth. is the trans shaft warped or could it be lack of something else. i have another tranny in an old k5 blazer that ended up being a parts truck. i guess i'll just have to swap it out huh.