After driving 25,000 miles in our 2019 Winnebago Navion 24D (including all the way up, around, and back from Alaska!) we saw a definite need to do some upgrading of our suspension. The truth is, these same modifications apply to all Sprinters, including delivery, Class B and Class C RVs. In the spirit of sharing what we learned from a LOT of research (and hat tip to Brian Terwilliger‘s fantastic testing of the various combinations of upgrades and advice he gives on Facebook), we hope this info will be useful to many Sprinter owners out there.
Just the shocks and sway bar
It’s true. There are so many possible upgrades you can do to help with drive comfort, noise, and steering, but by upgrading the sway bar and replacing the stock shocks with custom tuned shocks from Agile, we love the ride. Struts, springs, and other upgrades could have some improvement, but may actually have the opposite effect when combined with just the two upgrades. For example, the Sumo springs upgrade, which is common for Sprinter owners to add, can actually counteract the control from the new Agile Fox Shocks and introduce vibration. See below for specifics on the new gear. These upgrades apply to all models (although there will be slight differences in parts depending on your model year). For purposes of this article, we are presuming you have a 2008-2018 Sprinter 3500 chassis.
So what was the problem?
You’re driving down the road and a tractor trailer passes you, pushing you out of your lane with the force of air. A gust of wind blows you onto the shoulder of the highway. When you make a turn, the vehicle leans hard. Coming out of a driveway, it feels like you’re rocking back and forth more than sailing in a regatta. Meanwhile, all your stuff goes rocking and rolling all over the RV. Any of this sound familiar? While I’m not going to go into the how and why (here’s a great intro on Shocks from Mobil and one on swaybars/anti-rollbars/stabilizers), these become even more important with the heavier weights of modern RVs. The question becomes, what do you do about it??
Agile Fox 2.5 Shocks

This is some incredible engineering. Agile Offroad of Southern California saw the problems facing Sprinter 3500 drivers and took action by tuning/modifying Fox shocks that were originally built for Semi-trucks to work wonders for vans. The Agile Fox 2.5 Shocks are specifically engineered for 2015-current 3500 Sprinter chassis, and they make several other options for earlier models and 2500 chassis. Through tuning the damping and adding a custom length shaft, these shocks do a fantastic job improving your ride and work with your new sway bar to significantly reduce sway (like coming out of a driveway and rocking multiple times). Upgrading your shocks requires just 4 bolts, but be forewarned, these shocks are hard to compress by hand. We used a second jack to compress them once the first bolt was attached!
Hellwig Rear Sway Bar

The second part of the combination is a significant upgrade to the sway bar. The Hellwig 7254 Rear Sway Bar is the correct size and part for 2008-2018 3500 Chassis Sprinters. These include those badged as Mercedes, Dodge, and Freightliner. Sway bars really help with stability against wind, truck wash, and make turning corners a breeze. This upgrade requires 6 bolts and is definitely in the realm of an upgrade anyone could complete.
Did it really make a difference?
Yes, yes it did. Coming out of a gas station, the passenger used to almost feel like needing to brace themselves from the violent rocking resulting from simply pulling out of a driveway. The ride is smoother, easier to drive even with one hand, less overall rocking even at highway speeds and great stability against the wind. Plus, when we’re parked and walking around inside, the rig doesn’t rock so much and feels more like a sticks and bricks home. From a quality of life standpoint on travel days, this is probably the biggest improvement you can do yourself to your Sprinter. 10 bolts and about an hour of your time can make a world of difference!