Re: Can you check bellows midseaon?
If water is coming in around the shaft going into the coupler, you can bet there is water in the bellows. Milky gear lube in the drive lube reservoir would also be an indication of problems, water in the drive from somewhere.
Short of that, pulling the drive is about the only way of knowing for sure.
It would also help if you put your Engine Make, model, and year, along with type of drive, in your signature. Then we don't have to guess as to what you have.