When the pressure drops, springs result in the clutch to release. Evenly spaced ridges, named splines, line the inside and out of doors in the clutch to lock in to the gears along with the clutch housing. You can study more about these clutches in How Automatic Transmissions Function. A https://clutch-kereta86318.blogadvize.com/40348061/a-review-of-clutch-kereta