I can't tell you sure on a Holiday Rambler. But on some of the slide outs I've seen there are adjusters on the bottom of the slide out close to the outside underneath at the end of the rail.. It usually looks like a large bolt with nuts on it. You can lift or lower either side by raising or lowering the nuts. You need to know the clearance specs from Holiday Rambler to be sure you are adjusting it correctly. You should be able to do a very minor adjustment if you're carefull. Hope this helps some.
Jim and Lynda, (Sophie, Jake, attack trained killer Shi-Tzus :-))
2003 Fleetwood Expedition 38N 2005 Saturn Vue