Check the Pan Hard Bar bolts to see if they are loose, also look at the torque arm mount on the trans, make sure thats not slapping round up there. LCA's take a look at them too. Sway bar links? check em out
Clunking usually would refer to suspension more then trans unless the trans mount was bad. the scrapping would be more contributed to it. I had a clunking noise on my car, couldnt figure it out, especially when I turned, found out my PHB bolt was loose, allowing it to wear the bushing it was in, and letting it slap around.
EDIT: replace those sway bar links, they've seen better days, not the problem, just saying lol.