Should I rebuild my trans before we take trailer out west ??

Just don't hold it in reverse too long backing in, that's sure to test the clutch seals in your transmission. Line pressure about doubles on a 4l80 in reverse. They have valve body fix kits to relieve that on those trannys. I found that out the hard way,800miles from home. Backed in my site, and it never drove out, all the seals were in now in the bottom of the pan.