I receive several service calls per week from stranded RVers with panic in their voice because one of their RV slides will not retract, and I often hear “…and our check-out time at the RV park is in 30 minutes!”  The two most popular types of RV slides take periodic maintenance, but most RV Dealers don’t tell you that, nor how to maintain them. This post is about the most common of those, the Lippert (LCI) In-Wall or Thin-Wall “Schwintek” type.  In this photo, you can see the notable Schwintek aluminum gear tracks: My service calls are not because they are an inferior system (I actually like them best), but…