My clutch is making a knocking sound. I happens when reversing and I push the clutch back in while the car is still moving it makes several knocks in a row. (Only when the clutch is pushed to the floor) It does the same on occasion when going from 1st to neutral with the clutch pushed...It's not really loud, but it is noticeable. I checked the Slave and clutch fluid and they are both fine. Anyone else experienced this? Could this be the beginning of a throughout bearing going out?