[scottz]

It if is like mine (should be, the 3120 and 3160 are the same except for kitchen/dining slides swapped) the fresh water tank is in the rear bay, all the way in the back, taking up most of the area between the frame rails. Yes, it is right below the couch.

Several cross country trips and a trip to Alaska and my couch has never moved.

As for the "nails"; I pulled all of mine; about 60.

Some of them will spin out with a 1/4" bit, just like a screw.

Some of them will spin part way out and you then take a pry bar or claw hammer and pop them the rest of the way out or put pressure on them and continue spinning.

The stubborn ones will just spin and you take a pry bar and hammer to get under the head and pop them out.

Replace them with self drilling screws and washers (I used #10 x 3/4"). Use a good power driver or drill and wear safety glasses. While you are doing this inspect the skirting that rolls under the trailer and attaches to the frame. The factory did not use any washers on mine and after a few months, several had pulled through and others were loose. Put some washers on these.

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