When I start the vehicle and put it into drive we get a pretty good
clunk when
the transmission shifts from 1st to 2nd...and same on the downshift.
Anyone else experience this and how to fix it?

Come to think of it, I believe that it also does this kind of loudly
when parked and trying to engange it from Reverse to Drive as well.

Could it need a fluid/filter change? Drive shaft regrease? Please help.