side to side thrashing

[LA-HODAG]

I recently bought a 2007 Fleetwood Revolution (41 feet, no tag, Spartan chassis), now at 36k miles. I experience violent side to side rocking whenever my rear wheels encounter an offset bump, such as driving over a speed bump unless the coach is exactly perpendicular to the bump. This is especially a problem when making a right turn into a parking lot that has either a dip or rise along the curb, as nearly all do. I need to slow to under 5mph to prevent the violent side to side, and even at under 5 I think it is way too much. My coach is not overweight and the ride height is correct. Is this common on the non-tag axel coaches? My last rig had a tag and I did not experience anywhere near the side to side motion, even if I had lifted the tag to make a tight right turn, but it was a much heavier bus conversion so maybe not a fair comparison. Ironically, my fear that the lack of tag in a similar length coach would result in more front to rear "porpoising" has not come to pass. I beleive the rear suspension on the Rev is made much stiffer to combat porpoising, which may be the cause of my side to side. If the side to side action is common, is it correctable? I doubt this is a shocks issue but I would consider replacing them if that will help. What about rear stabilizer or sway bars? Would they affect this situation? Thanks.

[Algoma]

You may want to look at these. Motorhome Suspension Parts and RV Suspension Parts
I have the MCU's on the rear of my coach.

[FormerBoater]

My 98 Eagle is a 40 footer with no tag riding on a Spartan MM Chassis with IFS.

I do not experience any noticeable side to side motions and IMHO what you are experiencing is not normal.

Good luck in getting to the bottom of it!

DaveS
1998 American Eagle EVS

[Tha_Rooster]

I also have a 07 rev and have not had any of those problems. Is there a valve that controls lean, like letting air out of one side and adding to the other maybe it's flipping out.

[AFChap]

A solid rear axle will rock the vehicle when taking a speed bump or other sharp bump/dip at an angle. Try it with a solid rear axle pickup truck and see. When the vehicle is tall and heavy, naturally the rock will likely be more pronounced. CONTINUED rocking should not occur unless shocks or some other suspension components are bad. We have become so accustomed to independent suspensions that we don't know/have forgotten how a solid axle affects the vehicle on bumps.