Gimbal bearing is pretty easy to check, I recently had to learn all this on my Mercruiser 888. Pull the outdrive off (6 bolts) and reach in through the ujoint bellow and check. Shouldn't be any grinding at all. Should run kinda tight with a very smooth feel.
Before you remove the 6 bolts put in forward gear all the way. When reassembling line up shifter shoe while sliding outdrive back on.