My rebuilt trans (Dealer replaced, 40 thou since) on my 99 has a slight shudder when shifting out of park into gear (drive or reverse) and when shifting between the two. This is all while not moving. It seems to accelerate normally and shift ok between gears.
Is this a sign of a bad motor mount?
I hope...

 

might be- the front and right side mounts fail all the time
Do a load test while watching the mounts for motion

smell the fluid too