4l60e not engaging gears at all

i have a 95 gmc sierra 2wd 350ci. i turned a corner a couple weeks ago and went to hit the gas and truck just revved, when i shift it feels like it goes into gear but no movement. checked fluid was overfull so dropped the pan changed the filter topped off fluid, let truck run for 30 mins and the fluid was cold, there was a small ticking noise right before it stopped moving.

Obviously this is internal, something let go, has to come out and get disassembled for a diagnosis.