Cutter - Moho Right?
The Cutter is unfortunately a "Square Box" RV - even though it says AIRSTREAM it's not as wind slippery as the classic mohos or the trailers. It has a high center of gravity and presents flat sides to the wind.
Things that can be wrong?
TIRES - inflation and age. Are the tires more than 5 years old? Even if it's just sat, the rubber ages and degrades. Are they properly inflated and balanced, one out of balance or severely underinflated tire can start "the wave" where the moho starts to behave like a horse on a merry-go-round. Bad springs or airbags can cause this too.
LOADING: If you've got too much load on one side or one corner of you moho that can also start the bouncy-bouncy ride.
SHOCKS & SPRINGS & AIRBAGS: Pleeeee-us tell me you don't have the original shocks on your 13 year old moho! Even if you only have 10K miles, the shocks will lose their seals from age rather than use.
TOWED: If you were towing wave runners, you had to be using a tow dolly. If your "drop" is wrong and the dolly is nose up or nose down rather than running level - it's set up to rock and roll. Are you sure you've got the correct size ball. I saw a man towing his new Airstream with a 2 inch ball - new ones need a 2 5/16" ball - so the thing never locked down properly. The tail won't wag the whole dog, but it can make any other small instability bigger.
Most moho's zip past my teensy trailer thinking that they're kicking sand in my face. I concur. I've only seen ONE moho lying on it's side at the bottom of a big grade with smoke rolling out. I will slow down, especially on steep downhill grades and in bad weather (including high wind). It's simply the "wimp out and live" solution.
A big moho is less stable than a semi-tractor trailer, and if you ever feel "pushed" from behind or like a cross-wind is trying to force you into an involuntary lane change your best move is to take your foot off the gas. The other stuff is also important, but not as important as respecting two things WIND and GRAVITY. If your problem got worse going downhill -- that is an indicator that (A) some kind of maintenance is overdue or (B) your macho is driving while your brain is napping.
If you simply must be a speed demon, look for empty stretches of road across level territory, good visibility and great weather. Then go like a bat for 1/2 hour, followed by a day of driving like you're chauffering Miss Daisy!
Don't let death be the first clue that you're going too fast!
Today is a gift, that's why they call it the present.