[A/S] Frame Scraping

[David@xxxxxxxxxxxxxxxxx]

I recently acquired a 1990 32' Excella 1000 and I'm
having a problem when I back it into my driveway. 
Between the crown on my street and the (slight) upslope
on my driveway, the frame rails in the very back of the
trailer scrape the concrete.

This was not a problem with my 1974 27' Overlander
because it was shorter and it seems that the 1990
trailer sits a little lower as well.

I don't think the scraping is causing any damage to the
frame rails (other than paint obviously) because it is
slight but it sure sounds nasty and leaves marks on my
driveway.  Are there rollers that can be mounted to
these frame rails to avoid this?  Any other suggestions?

How low to the ground should my trailer sit?  Maybe
there is a suspension issue or tires.  I have checked
the inflation pressure and that is fine.

David Robertson