I renewed the bolts on my 1978 Trillium
There were 4 behind the axle
/ 2 under each
settee. In the front there was 1 on each side
under the Gaucho. One was missing and 3
snapped off when I tried to remove them.
Stainless steel bolts were so expensive I used
good quality 5/16" (hope I remember) bolts.
Before installation I painted the nuts, bolts,
and washers with several coats of Rustoleum
primer. Living in Arizona rust is not too large
of a problem.
The fun thing is putting them back in by
yourself. Clamping vice grips on the top bolt
heads to hold them while I was under the trailer
did the trick. The bolts are still in good shape
after 4 years. Of course the first ones lasted for
over 30 years.
Good luck on your project. I have been
considering pulling mine apart to repaint