So I take it that when a motor mount wears out, it starts to make noises that might make one think its a transmission related issue? Hence my other post........
when my bottom wishbone wore out I could hear a grinding whenever under a hefty load (Like going up a hill without downshifting.) Upon upgrading the sound went away, so I can only assume that that was the culprit. Granted I have the v6 so I can't say for sure, but I think it is a safe bet, especially if you have done any modifications supplying more power than the stock mount was meant to handle.
Yes. This happened with me when my passenger motor mount crapped out on me. Sounds like a grinding sound whenever you put the engine under a load. Replaced/upgraded it and the sound went away.