1998 Teton Slide Out Adjustment Help

I recently inherited a 1998 39', 3-slide, Denver Prestige model as my dad passed away. I am going over the entire trailer to check all systems to make sure everything works ok and about all I can find is the living room slide-out next to the entry door is way out of adjustment vertically (both sides). The trailer is perfectly level side to side and front to rear. It extends completely out at the bottom but the seals are away from the trailer wall by 3"at the top. I can easily rock the slide when it is fully extended to cause the top end of the seal to touch the trailer wall but it settles back to a 3" gap at the top. The kitchen slide and bedroom slide seal fine when extended and retracted. All slides are electric non-hydraulic.

I am listing this trailer for sale and want to make everything right for a new owner (or at least letting them know what needs to be done).
It's a beautiful trailer and deserves proper maintenance as needed when these issues come along.

Have any of you adjusted your slide-outs yourself or maybe had a shop do it while you watched in order to see what they did?

I have no manuals of any kind for this trailer. My dad bought it used and the previous owner did not include anything that would have come with this trailer when new.

Any help is appreciated. Thanks in advance. Bob