Personally don't know of any 40ft bounder issues of that vintage but if it has the tag axle (2nd rear axle) would get that checked out or look at it yourself depending on your mr fix it skill level.
What chassis is it on and what engine does it have? That information may give you a much better idea of certain specific issues related to ford or chevy chassis/engines, rather than specific to 40 ft bounder.
Im sure someone with one of those beasts will be along to help you more.
1987 Fleetwood Bounder 34'
*~*Stationary Fulltimers for now*~*