Yep an 05 is the SX series with a conventional gimble bearing like an OMC Cobra some parts are actually the same. You probably have water in the bellows so check the u joints and input shaft seal (rust on shaft can cause seal to fail oil leaks). This is why I/O owners should pull the drive once a season to check these things before they become expensive problems.
If you wind up having to change the gimble bearing get the right tools to remove/install it can be a bear of a job otherwise.
With proper maintenance (yearly drive pull, change bellows after 5 years) the gimble and u joints can last indefinitely. My gimble was installed in 2005, still fine, u joints are original 32 years old, still fine.
