Tips for Installing RV Sway Bar and Sumo Springs
We picked up our RV in the winter of 2016 and at a trim 25 ft in length, the Mercedes Sprinter 3500 chassis held promise for decent handling. The memory is still vivid, leaving the dealership, making a hard right turn, and startled at the lean and twist of the entire coach. I thought it was going to rip off of the chassis! That first lesson in driving the RV taught me two things: First, exit driveways and parking lots more carefully and, second, research ways to correct the side to side sway of the coach.
Reading the Sprinter forums, I found many people had resolved the problem by upgrading the rear sway bar with a beefier Helwig sway bar and installing Sumosprings. Sumosprings are not actually springs but are more like bump stops on steroids. The small OEM bump stops are less than half the height of the Sumosprings. That means the larger Sumosprings could reduce the amount of bounce when going over uneven surfaces. Both items sounded like reasonable upgrades.
Now that I am in my late 60's, I have adopted the adage "let someone else do the heavy lifting" whenever I can. However, after getting an estimate of $1,650.00 to install the sway bar and Sumosprings, I decided to install them myself. I had already priced the Sumosprings and Helwig swaybar at just over $500.00 and watched the videos on the install. Even at my age, I was confident I could do this myself and save a bundle in labor costs.
The swaybar install was easy. I simply removed six bolts and replaced the old sway bar with the new Helwig bar and hardware. Since the Helwing bar is much heavier than the OEM sway bar, I decided to use a floor jack to hold the new bar at the proper height while I started the bolts. On a scale of 1 to 5 (1 being the easiest), I would give this a "2". A quick job with a big return on my investment of time and energy.
The front Sumosprings are installed with just a nut and a washer. It's a little tricky since the threaded post is partially concealed by the frame. This is where YouTube can be a great resource, and watching the install video was the key. The mechanic used a small magnet to place the washer on the tip of the threaded post. Once he could feel the washer catch onto the post, he slowly slid the magnet away allowing the washer to drop onto the post.
Next, he used a deep well socket stuffed with cellophane to hold the nut in the socket. This made it so much easier to start the nut over the post. You may want to take note that the front end of the vehicle has to be raised a couple of inches in order to maneuver the new Sumosprings into place. I used a bottle jack to raise the unit just a few inches (the tires never left the ground).
The video showed the back bump stops literally pop out with a small pry bar or large screwdriver. So, after popping out the old bump stops, I used the same bottle jack to raise up the back end of the RV just a few inches to pop in the Sumosprings. Well, it wasn't quite that simple. I'm not sure if I was just tired from the installation of the other set of springs and the sway bar or if I just didn't have the angle right (maybe both), but I just couldn't "pop" it in as illustrated in the video.
I took a break, had lunch, and tried it again. My Dad was a life-long mechanic working on big trucks. I remembered laughing with him when we were having trouble fixing one of my cars. He offered some "tongue in cheek" advice: "Whenever you have difficulty working on any vehicle, start cussing at it!" Sure enough, a few choice words later (and maybe a different angle of attack) the stubborn bump stop popped right into place.
Once everything was installed, I wondered if I would be able to tell a difference in the ride. I have to answer with an emphatic YES! The sway of the coach is greatly reduced and the ride seems more controlled. The front end doesn't dip abruptly and the minimal body roll almost instantly corrects to the straight and level.
I have just over 30,000 miles on the RV and my only regret was not doing this sooner! Do your research and, if you think your unit has a bit too much "rock n' roll" consider checking out more substantial bump stops and a heavier sway bar
