Keith,
Try changing the level of the coach, raise the pass side and see if that makes a difference. When you hit the out button is the pump motor running, I believe your slides are the same as mine and the drive side room slide has the cylinders under.
Have you checked the hyd oil level in the pump tank?
Does the slide go out and return evenly, the rams have a accumulator so they both should have equal pressure in and out. That along with the guides is what allows the slide to stay even.
Listen to the pump motor when the slide goes out and in, it should have a constant even sound.
I guess the slide could be hanging up on something.