could it be your levelers 'cracking' under stress, or the chassis? is it a 'metal' sound?
mine does this, especially at the rear... sometimes on it's own, and sometimes when we move around inside the coach. Never been able to drill down to the source, even laying under the coach for a while and watching and listening, but I imagine it's some sort of chassis 'creaking'... sometimes we can go a long time without hearing it, days or weeks, and other times it seems all day long, especially in the hot months.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
110,000+mi since '14 - US, Alaska, Canada (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )b