Suspension

[rferg]

I have a 2012 Melbourne 29D. It has a large diameter rear sway bar and rear helper leaf springs. Don't know if it came that way or they were added. The previous owner says they he didn't install them and I know there was an owner before him. At any rate, Here is my question. The ride is a bit harsh. I trailer a Rzr and the trailer Rzr combo is probably 2,000 lbs. We do some boon dock camping and some of the places are rough to get into. Not extreme, just not maintained roads. Was thinking of removing the helper leafs and installing air bags to have an adjustable ride and to maybe get a little more lift on the rough roads so I don't drag any dump pipes, etc. off. I'm not real suspension savvy so could I get some ideas/input on doing this? Thanks.

[Grumpaw374]

Our last rig, a 2012 Forrest River Lexington was a 29 footer, anf like yours was built on a Ford E-450 platform, heavy duty, with factory helper springs and a very robust rear sway bar. Just no getting around the fact that the Ford E-450 is a very rough riding chassis, even with 8-9 thousand lbs of added camper weight. We towed a Subaru Crosstrek, about 3400 lbs, for most of it's 60,000 miles without a problem.
Ours came with a Forrest River added Firestone airbag system, and I upgraded the shocks to Bilstein's. Kept the airbags at around 70 psi, but remember, your probably running 70 psi or more in those six 8-10 ply tires, which in itself dosen't give a very soft ride.
Aside from a shock up grade and air bags, there's really not to much you can do to soften the ride or modify the harsh suspension.

[foglght]

Air bags are going to do the same thing the helper springs will with some exceptions. The helper springs are typically set up so they bring the RV back to unloaded ride height.

Normally if you wanted a better ride the suspension would be designed for a much lower spring rate, but maintain the correct "check load." The check load is the amount of weight the spring will support at a specific ride height.

F=kX Force = Spring rate * Distance

For Ford to change the check load they would have to modify the spring design specifically for chassis that are loaded up like motorhomes. Given they use the same chassis for every motorhome, they don't do anything.

Since Ford does not design the vehicles for normally being driven around at rear gross vehicle weight, the springs sag a bit, which is why some places add the hellwig springs, or in other cases the air bags.

There's even a super duper solution which is about $10k and is called liquid spring. If you want a nice riding class C.......that's it.

Both are accomplishing the same thing which is to support the load at closer to unloaded ride height. The issue is you are adding spring rate rather than just changing the check load. Stiffer springs means harsher ride.

The airbags will give you adjustable spring rate, but you'll either be purchasing an on board compressor or carrying one with you to add air to the bags. OR, you just keep them pumped up all the time which makes for an even rougher ride.

If you are going places where you have enough suspension travel to drag a dump pipe, it is unlikely you are going to find a solution to a better ride unless you actually lift the motorhome a few inches to give it more suspension travel. then you can soften things up a bit for off road driving. There is a place that makes lift kits for it.

https://weldtecdesigns.com/product/w...t-king-shocks/

The other reason coach builders add extra rear springs and the bar is to prevent roll. Adding the helper springs increases roll stiffness and with the center of gravity being so much higher than the design intent, the vehicles need more roll stiffness. If you take that away, you WILL feel the roll much more and it will have less stability on the highway.

If you put a lift kit on it, it will have less stability; but it will be awesome and you will be able to take it more places off road.