Volvo SX-M Not Going into Gear

[Bobbyh68]

I have 2005 Stingray with a 4.3GL engine mated to a Volvo SX-M 1.79 and the Shifter wont move. Last year the outdrive would pop out of gear at around 3000rpms and motor would over rev. I didn't have time to look into it before winter came. Now its spring and the boat is running fine But wont go into gear at all now... Please help, I think it might be a bad shift cable. But would like your guys input. Also where should I purchase new cable? (if that's the problem) Thanks in advanced, Bobby