Slide-out seals are wear items — but a seal that's wearing *evenly* will last 5+ years. A seal worn unevenly often dies in one season.
The 60-second check
- Run the slide all the way out.
- Walk around the perimeter. The seal should compress *evenly* against the wall.
- Look for daylight at the corners. Any visible gap = the slide is racking.
- Sweep a piece of paper along the seal. If it grips at one corner and drops out at another, you've got an alignment problem.
What causes it
- A loose drive nut on hydraulic systems.
- A motor pulling harder on one side (electric).
- A worn cable or stripped sprocket on cable-driven slides.
- The chassis itself flexing — the RV may need to be releveled before reading the slide.
If we catch racking early, we adjust and the seal lives. Caught late, the seal is shredded and we replace both the seal *and* fix the alignment.