Mercury - Quicksilver U-Joint Bellows Driveline Seal Ribbed Composite 60932A4. Overview. Keeping water out of your driveline is one of the most important parts of maintaining a MerCruiser. The Mercury Marine 60932A4 Quicksilver U-Joint Bellows seals off the bell housing to stop leaks and protect your u-joints and gimbal bearing from corrosion. It's made for MerCruiser MC-I, R, MR, Alpha One, and TR/TRS sterndrives, built from a tough, flexible rubber blend that bends with the drive while staying