Quote Originally Posted by JJ91284 View Post
Clutch piston (4 total) is what engages every clutch pack in the transmission. The way it works is trans fluid fills up the space on the bottom of the piston which then pushes the piston against the clutch steels and clutch friction plates. This then engages the clutch pack. If you didn't have a clutch piston the the clutch packs wouldn't engage.
very well explained thank you.