Like others, I've had a leak from the shower that causes water to drip under the trailer. The dealership happily charged me to caulk silicon between the shower pan and the shower glass on both sides - I've now removed that useless and potentially damaging non-repair - then sent me merrily on my way assuring me the problem was solved. It wasn't fixed and I still have an issue with the dealership on this one (sloppy investigating, incorrect repair) which I will take up with them later.
There's a (small, very small) furnace vent at the front of the shower base. Now I know I should have done this before
but finally I took it off after the most recent trip and looked in to find a swimming pool in the rectangular opening under the P trap. Water was leaking from the lower of the two drain nuts directly under the shower pan. Trying to tighten it while I was also making breakfast didn't produce the desired results so I had to wait until I got home. Here's the procedure:
Reaching in with one hand since there's no room for one or two more, I used brawny brute force
to loosen the nuts (see picture). It didn't take much. I also loosened the nut on the downhill side of the P trap and took the entire P trap and shower drain off to see if there was a crack somewhere since I hadn't been able to stop the leak before. Good news; there was no crack. There is, however, a rubber ring that sits inside the black pipe just above the P trap bend and seats against the bottom of the white shower drain. In this case it wasn't quite tight enough to seal properly.
I would have thought the dealership would have looked at that as being one of the primary causes of a leak under the shower but this way they I'm sure they were just doing their best to get me back for more customer-dealer appreciation.
(I admit, I'm a bit cynical here.)
When reassembling, the upper nut that sits against the shower pan is used to draw the shower pan centre upward (not downward!) against the drain flange. Here's why: the whole P trap assembly then rests on the subfloor and provides solid support for that part of shower pan. Hopefully the picture explains things better. Tighten everything firmly. If you can get tools in, you can get things tighter than I did but I have to be happy with hand tightening. There just isn't enough room to swing a tool in there.
I'm told that when disassembling and reassembling the drain from the shower pan, do it slowly and deliberately to avoid cracking the pan.
The bonus is that I just saved myself $300. Besides, if there's still a problem I can now complain to the repair guy in person.
Forest River Surveyor SP-230