actuator

I've had a problem with 2nd gear slipping to 4th gear then slipping into neutral. It has been an ongoing problem that my mechanics have yet to fix. I'm hoping to find some help online so when I take it back to the mechanics I can give them a list of possible causes that they haven't investigated...

Well, I know I need to replace a few solenoids on my actuator, so I might just replace the whole thing... so if somebody happens to have a new one lying around or one with low mileage... or spare solenoids, let me know please! Thanks!