Like Bryan said, weigh it. Corner weights (RF, LF, RR, LR) are best. If you can get those, set tire pressure on both sides according to the higher corner weight. Most of us can only get to a CAT Scale at a Truck Stop, and those give only Axle weight. If you go to one and have a toad, tow it onto the scales and you'll get its weight also.
And, again, if you need it aligned, go for 5.0L and 5.5R Caster. Make sure the front end isn't worn out. Both Bryan and I have renewed our Ford E-series front ends with takeoff parts from 4x4 conversion shops. Cheaper to replace with takeoff than to repair.
I wonder if your exhaust system is damaged. Leaking and/or jammed against the chassis. If pipe is against chassis or hangers are shot, you'll get noise inside. You'll also get noise if a "motor mount" is bad.
It'd help if you'd post Make/Year/Model of this coach. Also Miles on it and Wheelbase, plus Front/Rear Weights if you've been to a scale.