I started up the boat for the first time this season and noticed an audible knock. It sounded like rocks inside the crank case, but the engine ran smooth. Trimming up the drive quieted the noise so I figured it was a U-joint going bad. I noticed a slight tick starting late last season, but it cleared up after a little running. I replaced the bellows and gimbal bearing 3-4 years ago, and had the drive off early last season to replace a shift cable and everything looked fine, bellows still nice and soft and flexible, no signs of water inside.
I pulled the drive yesterday to inspect/replace the U-joints, and it was a different story. There was residual water inside, drive shaft is completely rusted, gimbal bearing is shot. Bellows had a bunch of rusty water in the bottom, and what looked like clear jelly. I pulled the drive bellows and did a full inspection, they look perfect. No cuts, scrapes, or cracks, still flexible and soft. No signs of water entering that way. Where else could water be getting in? The drive gasket was perfect as well, no rips or tears that could have allowed water to get between the drive and pivot housing.
I pulled the drive yesterday to inspect/replace the U-joints, and it was a different story. There was residual water inside, drive shaft is completely rusted, gimbal bearing is shot. Bellows had a bunch of rusty water in the bottom, and what looked like clear jelly. I pulled the drive bellows and did a full inspection, they look perfect. No cuts, scrapes, or cracks, still flexible and soft. No signs of water entering that way. Where else could water be getting in? The drive gasket was perfect as well, no rips or tears that could have allowed water to get between the drive and pivot housing.