I would suggest that you may have something under the slide that is lifting it as it comes in, or your bottom rails are dropped down due to a roller bearing failure. The top should move to the leaning inward position as the slide rails pull it in. The angle is controlled by the elevation of the outer ends of the rails as they move in. Too low equals top hanging out. If it is working right the top will contact the sidewall first and the rail will pull the bottom in last loading the top against the sidewall seal.
Really only three things can cause the problem.
1. Binding in the slide itself.
2. Something under the slide lifting it as it comes in.
3. Lower rails not raising enough as they retract, which lifts the slide tilting the top in first.
I have the correct PowerGear service manual for yours. PM me with your e-mail and I will send it to you.