Suspension Upgrades

kylecm

Member
Happy Holidays,

Oliver, my 2014 Thor Siesta 24SA has a little over 71k miles and is really starting to rock back and forth. I think its time for a few suspension upgrades. After endless searches of the forums and a ton of Youtube videos, I have decided on a few items. I am looking for opinions, good and bad, and alternatives.

Struts and shocks.

From everything that I have read, Koni is the great option. I guess there is an argument on the Fox shocks but those seem to be moving me out of my budget. I am looking at the whole project for under $1500 parts.

Koni FSD 8805 1056 - $157 each - Shock Warehouse

Koni 8705 Front - this one I am not sure about. The picture on ShockWarehouse just looks like a shock whereas others look like a strut. I wonder if their picture is off.

Front and rear bump

SumoSprings - SSF-106-40 for the front = $155 (Amazon)
SumoSprings - SSR-338-47 for the rear - $214 (Amazon)

Rear Sway Bar

Hellwig 7254 Rear Sway Bar - $194 (Amazon)

Any thoughts on this upgrade?

Thanks

Chuck
 

Philip53

2017 Winnebago Navion
Try better shocks (Agile Fox) and Sumos first, drop the sway bar 'till shocks and Sumos installed. May save you couple hundred dollars you don't need to spend. I have had a bad handling experience with overly stiff sway bar--wasn't needed, H-D shocks did the trick. Search for threads/posts from Calbiker. Good luck.
 

kylecm

Member
Try better shocks (Agile Fox) and Sumos first, drop the sway bar 'till shocks and Sumos installed. May save you couple hundred dollars you don't need to spend. I have had a bad handling experience with overly stiff sway bar--wasn't needed, H-D shocks did the trick. Search for threads/posts from Calbiker. Good luck.
Thanks. I saw the posts from Calbiker, one of the threads had 21 pages, and I got lost in all the information. Thus my post.
 

Philip53

2017 Winnebago Navion
Kyle, concerning sway bars, the jist of his testing (and experiences) are that they are not necessarily needed with the aforementioned other changes, and may in fact lead to a more stiff ride than is necessary to stop the rocking motion you want to remedy. This was exactly my previous experience as well. Save some money, you can always add later if you think it would be needed.
 

Daystar

Member
If you can wait a few months, the Bilstein 22-249326 B6 Series Suspension Strut Assembly will be available in this country. It is their heavy duty line.
 

Mike DZ

2016 View 24V (2015 3500)
Thought I made a post on this early this am - but here is the gist - if you are a DIY'er, you could do your mods one at a time and gauge the results for yourself as suspension / ride characteristics are subjective - i.e. there is no objectively correct / one size fits all answer. I personally have sumos front and rear, commercial Agile Fox rear shocks and the Helliweg. I went with those to resolve various ride characteristics, not necessarily rocking, but tracking in wind, compression on whoops, and lean on curves and turns
 

Old Crows

Calypso 2014 View Profile
Suggest.

Skip the sway bar... stay with the OEM.

F & R Sumos you listed

R Koni FSD 8805-1056

The front Sumos will provide progressive, increasing resistance to upward motion (jounce) and will compensate for any wear in the front struts. The Koni FSDs and Sumos will help damp the longitudinal roll common to the Sprinter Class C RVs.

Also, tire sidewall flex is important so it is important to use no more than the placarded tire pressures. You may be able to drop down a couple PSI with some experience. (Assuming you are using the OEM Continental Vancos)
 

calbiker

Well-known member
I see this discussion never ends. Those who want to improve stabilization get pulled in all different directions. I've been following Sprinter MH suspension discussions for 12 years! The one thing I've found out is that almost always when people make a suspension mod they rave about it. Even when the mod makes no or little improvement, they still think it's the greatest. I got fooled into believing these false perceptions. That's when I decided to build test equipment that can test the suspension. The suspension tester differentiates between good suspension mods and poor ones. Testing has been ongoing for over 7 years. Mods that improve sway and rocking:

1. Fox modified shocks from Agile are the absolute best mod. Make that mod first.

2. Koni red struts, adjusted to max damping.

Bigger sway bars are a mixed blessing. Install Fox shocks first to determine if the side push from passing trucks is adequately tamed.

I haven't tested Koni FSD shocks/struts. I'm 95% certain they don't have enough damping. I'll be happy to test anybody's MH who has them installed. So far I've only gotten declines when I offered testing their vehicle.
 

kylecm

Member
I see this discussion never ends. Those who want to improve stabilization get pulled in all different directions. I've been following Sprinter MH suspension discussions for 12 years! The one thing I've found out is that almost always when people make a suspension mod they rave about it. Even when the mod makes no or little improvement, they still think it's the greatest. I got fooled into believing these false perceptions. That's when I decided to build test equipment that can test the suspension. The suspension tester differentiates between good suspension mods and poor ones. Testing has been ongoing for over 7 years. Mods that improve sway and rocking:



1. Fox modified shocks from Agile are the absolute best mod. Make that mod first.



2. Koni red struts, adjusted to max damping.



Bigger sway bars are a mixed blessing. Install Fox shocks first to determine if the side push from passing trucks is adequately tamed.



I haven't tested Koni FSD shocks/struts. I'm 95% certain they don't have enough damping. I'll be happy to test anybody's MH who has them installed. So far I've only gotten declines when I offered testing their vehicle.


Thanks for the info. Right now I have a box with Koni Red Struts and Red Shocks. Plus a Hellwigg sway bar and throw in the front and rear sumo bump stops.

I had already ordered everything listed based on my really bad research, lol.

I am mechanically inclined but live in a townhome in DC which means my RV sits in a storage area and I have minimal tools to do installations of this magnitude.

With that said, I am heading to my hometown in West Virginia (8 hours away) in which I can install everything on the 28th or nothing.

Given my bag of tricks I have, what would you install? What would you not? What would you just sell on eBay (or other forum) and use the money towards something else.

Note: I can easily return the bump stops and sway bar to amazon.

The shocks and struts came from another source (sprinterstore) so those are mine.

Thanks again for all the info.

Chuck


Sent from my iPhone using Tapatalk
 

calbiker

Well-known member
Go install the Koni reds shocks & struts. Make sure you adjust them to max damping. The shocks have a rubber bump stop inside them that needs to be taken out before adjustment can be made. Pull shock apart (as far as it goes) in insert a bike spoke (or similar) in the bottom hole to push bump stop up & out. Now collapse shock and rotate the two sections for max adjustment. When fully adjusted, you will not be able to pull shock apart (by hand) to get the correct mounting length. I put one end of shock in vice and grab the other end, with one foot braced against the vice, I pull as hard as I can. The shock will slowly expand. You'll notice the huge difference in damping between the min and max setting. Your MH needs that damping (and then some).

A lot of people like the Sumo springs. I worked with them while they were developing their Sumos. They are a first rate outfit with great people working there. I tested a lot of different versions for them. My biggest concern for my MH was sway and rocking and that's what I tested. I didn't see any reduction in rocking with Sumos. When you analyze the issues, rocking is controlled by damping. Sumos don't really affect this aspect of the suspension control.

Install shocks & struts first. Take test drive.

The Sumos are's difficult to install. Can do that at home. Need to slightly lift vehicle (tire can still be touching ground). I've swapped Sumos, Timbrens, shocks, struts many, many times.
 

ani_malfunction

New member
I see this discussion never ends. Those who want to improve stabilization get pulled in all different directions. I've been following Sprinter MH suspension discussions for 12 years! The one thing I've found out is that almost always when people make a suspension mod they rave about it. Even when the mod makes no or little improvement, they still think it's the greatest. I got fooled into believing these false perceptions. That's when I decided to build test equipment that can test the suspension. The suspension tester differentiates between good suspension mods and poor ones. Testing has been ongoing for over 7 years. Mods that improve sway and rocking:

1. Fox modified shocks from Agile are the absolute best mod. Make that mod first.

2. Koni red struts, adjusted to max damping.

Bigger sway bars are a mixed blessing. Install Fox shocks first to determine if the side push from passing trucks is adequately tamed.

I haven't tested Koni FSD shocks/struts. I'm 95% certain they don't have enough damping. I'll be happy to test anybody's MH who has them installed. So far I've only gotten declines when I offered testing their vehicle.
I am contacting Agile for more information, but on their website they say the Koni red struts are only compatible with the 2007 and newer sprinters. Do you have any different recommendations for struts on the T1N series? I have a 2006 and the front suspension needs replaced, so figured I would upgrade it in the process!
 

ani_malfunction

New member
Not true. I have a ‘06 3500 Sprinter and installed Koni struts.
Good to know, guess I'll just have to wait to talk to them on the phone. I've tried both calling and emailing. Cal, in all of your posts you recommend the Fox shocks and the Koni red struts over anything else. It seems a lot of people only bother to upgrade the rear shocks. In your research and testing do you recommend doing both the front and rear? I'm sure having all of them replaced makes a difference, but how much of one? I'm having an issue where the van I just bought needs the front suspension replaced before I drive it back to Oregon. Certain products seem to be backordered at the moment, and I hate to pay for new (probably OEM) parts, then go back and replace them with the upgrade I want within a few weeks or months. Also don't want the van to break on my drive home haha so trying to find the right balance of replacements for the time being.
 

calbiker

Well-known member
The front struts are just as important. The OEM struts are so weak that the front end would bottom out when driving on the freeway and encountering a dip in the road. It's not like the struts got weak after years of use. The vehicle was brand new. The very first thing I did was to install Koni reds. The suspension never bottomed out again.

Koni struts
 

1hen2ducks

2006 SHC & DAD owner
It's shocks and struts changing time again; In a nutshell, what would be the recommended >> KYB shocks and struts << for my T1n conversion van.
I do typical Baja driving occasionally, otherwise US driving and camping.
Any advice would be helpful. Part numbers would be a blessing.

Thanks, Mike Cady and Sally Sprinter
 

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