Plastic Fenders

[Super_Dave]

I'm starting my second season with the new 5th wheel and just brought it home last week from storage. I noticed that one of my plastic fenders has several cracks in it starting from the screw holes. It is obvious that the screws were over tightened causing stress on the plastic. I have no idea whether the cracks started with wind stress while driving or Winter cold making the plastic more brittle. Thought that I would just mention it so those getting new rigs can add one more item to their pick up check list.

[valhalla360]

Fairly common if you look at used RV's.

It's likely not over tightening but differential contraction when it gets cold. Sidewall of the trailer contracts more or less than the plastic cover, the screws can't move...so something gives...in this case the plastic cover.

Drilling them out a little larger and putting a rubber washer in should help by allowing a little movement around the screws.

[RobWNY]

I had that happen on the travel trailer I had before I got our 5th wheel. I bought new fenders but they're very expensive for what they are. When I installed the new ones, I put a dab of color matching silicone caulk over the screws (I know Silicone is a bad word in the RV world but it's a plastic fender that gets replaced if it breaks so no harm/no foul). It did the trick. No issues from then on. It was one of the first things I did to our 5th wheel when we got it. It survived the first year travels and winter storage just fine.

[Twomed]

Yep...they just jamb a self drilling screw in them. Best thing you can do is remove them, carefully drill the hole a little larger, rubber washer or o-ring on both sides. Also a 1/4" aluminum backer plate if the screw is just stuck into sheet metal.

Kind of a pain but...a couple of hours now may save you trying to find a replacement on down the road.