I had a 2000 HOliday Rambler Endeavor DP, and adjusted the slide. Yours is probably similar. From the link above by MountainAir05, click the link titled instructions for slide-out room vertical adjustment....and follow those steps.
In addition to the adjustments described by power gear for vertical adjustment, there were some rollers inside the kitchen cabinets (kitchen in slide) that can be adjusted. The power gear illustrations do not illustrate these rollers that are inside the kitchen cabinets and under the sofa. Some of those rollers are hard to find.
It's not hard, but make small adjustments and check the results.
Fred