1/2" sound like a lot. When you slide is closed how far off are the paint lines?
The attached is what I have in my tech library, but I have never messed with my bedroom slide. So I look forward to your summary after you fix your problem.
See .pdf attached for adjustment info. And note the extension adjustments shown in the diagram below does not give you much information on how to adjust the slide-box-height.
To understand (possibly) how to adjust the bedroom slide-box-height, the video link below may be of some help. Note: The RV in the video is for a gas rig, but I think it talks about the same bedroom slide (aka single cylinder type) we have in our 40' and 38' diesel rigs when the bedroom slide extends on the driver's side.
However, I don't know where the adjustment bolts are located or how to get to them if you are trying to raise your slide-box? ...When you check your paint lines that may give you a few ideas too.
Here's the video for reference:
Note: Winnebago 36' RV floor plans have different bedroom slides, so you guys need to keep this website forum link in your tech library when adjusting your bedroom side... which shows how you guys need to get to your cylinders when they leak:
https://www.winnieowners.com/forums/...ml#post3861497
Note: Slide creep is a different issue that involves solenoids or check valve.