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MW22r · 09-27-2021, 05:31 PM

The more I read and study previous posts on this forum it seems that progressive rate springs would soften the ride on my 2019 Ford E 350 class C more than just changing out shocks? How to choose the proper springs is the question since it is almost impossible to find out what the existing spring rate is? What say you?.....bob

Ron Dittmer · 09-27-2021, 06:11 PM

Hi MW22R/Bob,

Before changing anything on your 2019 Ford E350 chassis, you first need to research your specific rig. Don't take other people's word on what you have.

I advise to call your area Ford dealer, provide your chassis VIN number and ask what the ratings are of your front and rear springs. With that information in-hand, weight your rig during your next RV trip, then compare how your actual load compares to the front and rear spring ratings. For short rigs with 138" or 158" wheel bases on the E350 chassis, owners often learn that the rear springs are loaded at or near their max load rating, but the front springs have lots of extra margin. That "extra" translates to a high-riding, rough-riding front end. The information presents the option to change the front coil springs to the next available rating less to lower the front to better "level" the rig, along with improving comfort and handling. Lowering a high-riding front axle also raises the tail by roughly half the amount lowered.

Your actual weight on each axle also determines what your tire pressure should be. There is a world of difference between 80 psi and 50 psi in front tires. The proper tire pressure for the load it carries, provides a better ride and better handling. The same applies to the rear tires. 80 is much worse than a required 60. It is critical to use an accurate digital tire gauge.

As far as shocks are concerned, I personally appreciate the Heavy Duty Bilstein shocks I installed a few years ago. But shocks are surely a subjective matter by some people. I would leave that decision for a later time, after you have evaluated your springs and tire pressure.

Some short rigs with a 138" or 158" wheel base are built on an E450 chassis. In those cases, I suspect both front and rear springs are subject to scrutiny.

Longer E350 and E450 rigs with longer wheel bases have different dynamics. They often don't need to do anything with springs. But still I would evaluate them to make certain.

I am surely no authority on this forum. I only share my personal experience along with personal projections. For every point, there is a counterpoint available by another forum member.

Winterbagoal · 09-27-2021, 06:13 PM

Maybe have a look at Sumo Springs? They have all sorts of stuff that's supposed to soften the ride by replacing the factory bump stops with constant contact molded urethane "springs" that compress as the frame and suspension interact. There are varied degrees of firmness. Kind of like looking for a new mattress for your chassis.

MW22r · 09-27-2021, 06:26 PM

Ron. Thanks for the update. I have read most of your posts for years and I think you have provided the definitive summary on suspension. It seems like everyone immediately wants to swap out their shocks (Koni or Bilstein) but I now understand that shocks are "dampers" to minimize the boingy action of springs when the springs really take the initial force of a bump or pothole in order to keep the tire on the road. Good advice about calling the Ford dealer. You are located not too far to my south so you know the area I live in is kind of out in "podunk" as far as service options. Elkhart, Grand Rapids and Kalamazoo offer some alternatives but I have yet to find a Ford Dealer(even a Ford Truck Dealer) who will even perform an oil change. I am not very mechanically inclined so thank goodness for the folks on this forum and You Tube to explain what to others may seem as very basic mechanics.....Bob

Winterbagoal · 09-27-2021, 07:25 PM

Quote:

Originally Posted by MW22r

Ron. Thanks for the update. I have read most of your posts for years and I think you have provided the definitive summary on suspension.

Seriously? Good luck, Bob.

MW22r · 09-27-2021, 07:39 PM

Yikes!

donr103 · 09-27-2021, 07:42 PM

You doing work or shop?

Ron Dittmer · 09-27-2021, 10:07 PM

Quote:

Originally Posted by Winterbagoal

Seriously? Good luck, Bob.

Per my closing statement....."I am surely no authority on this forum. I only share my personal experience along with personal projections. For every point, there is a counterpoint available by another forum member."

Bob, If there is no Ford dealer in your area, just call any Ford dealer to retrieve the information concerning what springs your chassis is outfitted with.

sibe · 09-28-2021, 05:17 AM

Good info here, Ron has done alot research and his own real world experiences... Personally I have some experience with suspension and alignments from the collosion industry but RV's are tough... manufacturer designs, specs, layouts and chassis design as ordered etc... makes for a unique approach full of confusion, trail and error and some luck.. or you find someone with EXACT model you have and see what worked..

RonandDeb · 09-28-2021, 06:16 AM

Quote:

Originally Posted by Winterbagoal

Maybe have a look at Sumo Springs? They have all sorts of stuff that's supposed to soften the ride by replacing the factory bump stops with constant contact molded urethane "springs" that compress as the frame and suspension interact. There are varied degrees of firmness. Kind of like looking for a new mattress for your chassis.

This is what I did. Before running out and spending a ton of cash on sway bars and shocks, try the Sumo springs. They are a breeze to install and personally, I found them to be all that's needed, for me anyway.

Phil G. · 09-29-2021, 01:50 PM

Quote:

Originally Posted by MW22r

The more I read and study previous posts on this forum it seems that progressive rate springs would soften the ride on my 2019 Ford E 350 class C more than just changing out shocks? How to choose the proper springs is the question since it is almost impossible to find out what the existing spring rate is? What say you?.....bob

Congrats on your 22R - the specs and features read like that should be a great compact Class C! It's similar in many ways to our E450 based, Winnebago Itasca 24V Class C except for, because of it's E450 chassis, our's probably used to ride even worse than your E350-based one does.

What I did was just change the rear shocks (the front I left as stock) to special shocks that provide little to no damping on sharp bumps - thus not adding their stiffness in the rear to the stiffness of the rear springs on sharp bumps. By "sharp bumps", I mean roadway potholes and cracks.

In the rear I changed to automatically adjusting Koni F.S.D. shocks - which add little to no damping to the already stiff rear springs on sharp (high frequency) bumps - but in real time self adjust to provide (low frequency) heavy duty damping otherwise.

My shower in the rear used to have it's shower door latch always come loose with the stock Ford OEM E450 shocks in the rear. Now, since changing to the Koni Frequency Selective Damping shocks in the rear, that shower door latch never comes loose.