Hi. Had an 1990 Coleman Sun Valley for about 10 years. We bought it used in about 2000. We loved it. It was a smaller one 8' X 10', only the beds pulled out, no bathroom either. We never eat or cooked inside just slept in it. Took it all over southern, central and eastern California. It was perfect for myself, wife, daughter and daughters friend.
Suspension was a simple leaf spring assemble. Tires were over sized trailer tires, wider then a normal truck tire but not as tall; a bit expensive to replace but fairly easy to get. It was really easy to pull tire and grease the wheel bearings, too. I carried a scissor jack to make changing ties or working on it easier. Trailer never had any troubles on hard packed dirt or gravel roads. I thought she was great. She is long gone now, but some days I still miss her and the simple family trips we took with her.