if water is coming in on the steer arm its probally the upper pin assembly

One way to determine if the leak is in the bellows is to have someone watch and or listen to the leak while you raise and lower the drive, also turn the wheel through it's full rotation.

Watch and listen to see if the leak intensifies at any point.

If you have a small crack in between the pleats on one of your bellows, moving the drive around can stretch it open and allow more water in.