Forum Discussion

Phedley's avatar
Phedley
Explorer
Oct 24, 2021

Stability control

I have a just acquired 2007 winnebago Navion that has stability control issues. I’ve checked tire pressure air bag pressure all is good. Any suggestions on how to correcting this horrible feeling of being out of control?
  • No, on doubling the shocks or other hardware.
    I am in the process of adding Sumo Springs to try to mitigate the curb roll, and sway from driveways and 18 wheeler bow wash. If the handling improves, that would be a bonus, but I'm only after a low speed rock and roll improvement. These things have very mushy suspension, and the gap beteeen the frame and suspension bump stops is pretty wide, probably to soften the ride, but the trade off is serious wobble entering/exiting even slightly angled grades and driveways. If it works, great. If not, no harm done.
  • Yea bought some of the SumoSprings also. The yellow one. Have not installed yet. Let me know how your results are. I’ve driver 18 wheelers and such but never this bad.
  • The curb roll on my 30' Cambria was minimized by the addition/changing of the shocks to Koni vs. what Ford installed on the chassis. Curious to see what the Sumo can do. Was under the impression they were meant to be more of a weight bearing device.
  • klutchdust wrote:
    The curb roll on my 30' Cambria was minimized by the addition/changing of the shocks to Koni vs. what Ford installed on the chassis. Curious to see what the Sumo can do. Was under the impression they were meant to be more of a weight bearing device.


    They're a constant contact compressible bump stop between the suspension and frame, is how I would describe them.
    At least the ones I'm trying are. I have added the yellow rears (1400lbs combined support at 50% compression) SSR-338-54, and so far, they have done what they promised. I'm seeing reduced push/sway due to cross winds/big truck bow wash, and I used to bottom out the tail, if I left/entered my driveway a little too fast. That hasn't happened either.
    I was impressed enough that I ordered the fronts SSF-106-47 (1000lbs at 50% compression) hoping to add some more stability to cornering and curb roll. Even a bit of improvement will be worth it. Still waiting for them to arrive.
    My factory shocks are Bilsteins, and I haven't read anywhere that changing them out was worth the effort/cost, so I'm waiting to see if the Sumos alone will give me enough improvement.
  • I just installed the yellow sumo springs what a difference. I will be putting them on the front. Thanks for the update!
  • Phedley wrote:
    I just installed the yellow sumo springs what a difference. I will be putting them on the front. Thanks for the update!


    Good news? I've decided to wait for a while, and a few more miles to add the fronts to my chassis. The rears do seem to help, so I may not need the fronts after all, but I have them, if needed. Weather is starting to chill up here, which also helped decide which way to proceed.
  • I installed front and rear sway bars, Bilstein shocks, safeT steering arm, wheel aligjment corrected tire pressure and it made a great improvement to my driving experience
  • Harvard wrote:
    Your unit has too little caster.


    Not very helpful, as the OPs motorhome is on a Mercedes chassis.

    To the OP, I haven't seen too many handling complaints about the Mercedes chassis. Part of may be your expectations, depending on what they are. Although some say they do, these things don't drive like SUVs. Have you owned other motorhomes?

    I haven't seen anyone mention weights. GVWR is pretty low for a motorhome this size, and it would not take a huge overload on the rear axle to make it handle terribly. I would start by knowing your weights.
  • Another item that un-stabilizes the RV'S is to much weight in the overhead bins, higher center of gravity over all specially galley items as an example plates made of porcelain, caned goods ETC. rather than using some thing lighter, we started off with plastic dinner ware made by Ingrid LTD. and wife latter bought a set of Corelle and substituted for the plastic.

    The plastic dinnerware weigh more than the Corelle and all glassware is acrylic, all coking utensils are aluminum made by Tefall they ride under the sink in cloth bags for rattle abatement, the BBQ rides in the toad, and all heavy items ride low this ensures that the center of gravity is as low as possible since a good gust off wind will push the RV and being top heavy will tend to steer to the opposite side of where the wind comes from or the bow wave push is, this motion is amplified even more than when the center of gravity is lower, that leads to stability problems.

    navegator