Sprinter suspenstion upgrades?

rvthereyet

2015.5 Unity TB
A while back, while we were getting our replacement galley window installed in Dallas, TX, we talked with a fellow sprinter owner about suspension upgrades.

He apparently has experience in this area, and highly recommends the below.

While up in Gainesville FL for the front end alignment last month, I talked to the service adviser.

He said that if we brought him the parts, he'd install them, and would not void the warranty.

What we need is someone more versed in this area that I am to chime in with your thoughts.

Thanks in advance.

--Tom

(posted with Bill's permission)...

=================================

Kathy,

I promised to send out the details to the Sprinter suspension upgrades that I have done. So, here are the details.

My issue with Sprinters is they are a bit top heavy (duh) and waddle, wiggle, sway and bounce down the road. Fortunately, the after-market parts people have solved it almost completely. After picking mine up at the factory last month ago it definitely needed some help. I got to know the technical staff at the factory and their official response is: “we are an authorized MB outfitter, so we make no modifications to the Sprinter chassis or MB will pull our license”. They don’t even drill a hole in the frame to add the Unity body. Wow! After further discussion, they admit that the Unity could use some help and most owners do some of the things I did.

The expertise that I bring to the group is MB and Sprinters. I have had a bunch of the MB products and know them better than most. I’m also a bit fearless when it come to twisting a wrench to get something to work better. All of the upgrades that I’m suggesting will not effect warranties. They are not modifications but upgrades. A subtle but important difference. I did all of the upgrades in my driveway with common tools. I have also discussed this with the Plano dealer MB tech. He will be doing my front-end alignment on Thursday. He seemed a bit amused that I was doing all of these Sprinter upgrades in my driveway. All in, it took me 3 hours to install all of it.

If you are reasonably handy, you also can do these yourself. If you need a little coaching, please ask. It will be the best $1,300 you spend on your rig! The ride and performance improvement are unbelievable. We are taking 40 MPH curves at 60 MPH and stuff isn’t shaking out of the cabinets on curves and on entering/exiting fuel stations. The machine simply performs better, is even more pleasurable and safe to drive.

Parts/prices, sources and problem resolution:

My unit - 2015.5 Leisure Travel Vans Unity MB on a 2015 Mercedes Benz Sprinter 3500 cab chassis.

These parts work for a 3500 Sprinter 2007 - 2015:

Koni shock 8805-1047 (2) rear $165/ea, UltraRVproducts.com, keeps the rear end much more composed
Koni shock 87-2657 (2) front $221.50/ea, UltraRVproducts.com, stops the front end from bobbing
Hellwig rear anti-sway bar (1) 7254 $183.62, Amazon, sway/waddle is gone!
SumoSprings front (pair) SSF-106-40 $177.30, Supersprings.com, truck passing and wind sway
SumoSprings rear (pair) SSR-335-47 $185.20, Supersprings.com, truck passing and wind sway
MB camber adjusting bolts (2) , 001-990-77-00 $25, MB dealer, when you change the front shocks you have to have the front-end aligned - theses bolts allow for adjustment.

This sounds complicated but really it is not. I have done the homework for you. I also have the torque specs on all of it.

Bill Case
 

jackfish

Active member
I have all those items installed except the MB camber bolts. Can MB install the camber bolts during regular service, do they usually have these on hand?
 

rvthereyet

2015.5 Unity TB
I have all those items installed except the MB camber bolts. Can MB install the camber bolts during regular service, do they usually have these on hand?
Not sure, but will ask.

By the way, please let us know if your upgrade was worth it, any regrets etc?

Does the RV handle better as he describes?

--Tom
 

Custommm

Member
" I also have the torque specs on all of it."
would be nice to have that precious list !
Thank you
 

Don Horner

2012 Unity IB
I installed the Sumo Springs only. My problem was the excessive side-to-side sway when exiting some driveways at an angle -- it could really be radical. Since installing the Sumo Springs (not actually springs, but bounce absorbing bump stops), the side-to-side sway still happens, but is damped quickly and no longer goes as far. I'm satisfied with the rest of the ride, so I'm satisfied overall.

I should add that as a former builder of autocross cars my son used to win state and regional championships, I'm very familiar with adjustable, gas pressurized shocks like Koni and Tokico, and with larger, stiffer sway bars. But, I'm not trying to turn my Unity into a sports car. I agree the changes add some measure of security to the Unity, but for me, and in my opinion only, not enough to justify the cost.
 

Old Crows

Calypso 2014 View Profile
*40 mph curves at 60 mph*

Why?
 

Chip D

Chip D, 2013 Serenity
These parts work for a 3500 Sprinter 2007 - 2015:

Koni shock 8805-1047 (2) rear $165/ea, UltraRVproducts.com, keeps the rear end much more composed
Koni shock 87-2657 (2) front $221.50/ea, UltraRVproducts.com, stops the front end from bobbing
Hellwig rear anti-sway bar (1) 7254 $183.62, Amazon, sway/waddle is gone!
SumoSprings front (pair) SSF-106-40 $177.30, Supersprings.com, truck passing and wind sway
SumoSprings rear (pair) SSR-335-47 $185.20, Supersprings.com, truck passing and wind sway
MB camber adjusting bolts (2) , 001-990-77-00 $25, MB dealer, when you change the front shocks you have to have the front-end aligned - theses bolts allow for adjustment.

Bill Case
Thank you Bill for doing the leg work on this.

The swaying when going into or coming out of a parking lot would be my first problem that I would like to stop.

I don't have a problem really with my Serenity when driving down the road, and it appears to be pretty stable with trucks and what not. Drove from Omaha to Chicago a year ago with a 40-50mph side wind, and it was doable. It wasn't enjoyable, but it was doable!! Have driven from Omaha to the West coast 3 times so far this year, and really don't have too much problems with wind.

The biggest problem that I'd like to permanently solve is the "bouncy bouncy" ride that is at the rear of the unit. I've given some thought to the GlideRite technology which uses a bunch of air bags. But I don't know of anybody that has done it. I'd hate to drop $4-5,000.00 and find out I still have the "bouncy bouncy" problem from the unsprung springs. Dunno. Maybe air bags might help a bit.

That and the road noise, but that's another topic.

Chip D
 
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Old Crows

Calypso 2014 View Profile
Thank you Bill for doing the leg work on this.

The swaying when going into or coming out of a parking lot would be my first problem that I would like to stop.

I don't have a problem really with my Serenity when driving down the road, and it appears to be pretty stable with trucks and what not. Drove from Omaha to Chicago a year ago with a 40-50mph side wind, and it was doable. It wasn't enjoyable, but it was doable!! Have driven from Omaha to the West coast 3 times so far this year, and really don't have too much problems with wind.

The biggest problem that I'd like to permanently solve is the "bouncy bouncy" ride that is at the rear of the unit. I've given some thought to the GlideRite technology which uses a bunch of air bags. But I don't know of anybody that have done it. I'd hate to drop $4-5,000.00 and find out I still have the "bouncy bouncy" problem from the unsprung springs. Dunno. Maybe air bags might help a bit.

That and the road noise, but that's another topic.

Chip D
FWIW, If you want to stop the side to side oscillations..... I'd go with the SUMO bump stop replacements (rubber baby buggy bumpers) that fit snugly between the axle and the frame. That works.....
Start with the rear and see how that works. More springs, stiffer anti-roll bars are NOT the solution. And they are not expensive.....

:popcorn:
 

Don Horner

2012 Unity IB
Thank you Bill for doing the leg work on this.

The swaying when going into or coming out of a parking lot would be my first problem that I would like to stop.

I don't have a problem really with my Serenity when driving down the road, and it appears to be pretty stable with trucks and what not. Drove from Omaha to Chicago a year ago with a 40-50mph side wind, and it was doable. It wasn't enjoyable, but it was doable!! Have driven from Omaha to the West coast 3 times so far this year, and really don't have too much problems with wind.

The biggest problem that I'd like to permanently solve is the "bouncy bouncy" ride that is at the rear of the unit. I've given some thought to the GlideRite technology which uses a bunch of air bags. But I don't know of anybody that has done it. I'd hate to drop $4-5,000.00 and find out I still have the "bouncy bouncy" problem from the unsprung springs. Dunno. Maybe air bags might help a bit.

That and the road noise, but that's another topic.

Chip D
First, definitely agree with Old Crows about the Sumo Springs. We have several commercial driveways in our area that slant down to a gutter and then slant back up to street level. When negotiating these at an angle, the Unity would slam side-to-side enough to make things open, stuff fall off and the cupboards to get jumbled. Since we installed the Sumo bump stops, the side-to-side oscillation still begins -- but is quickly damped to a level much less dramatic.

Regarding the bouncy-bouncy in the rear -- we had a Free Spirit based on a T1N 2500. It had a rear sofa. It was so bad, folks sitting there would actually leave the seat on slightly bumpy roads, and kids (who enjoyed it) would actually hit the ceiling (probably with a little assist by bouncing themselves :D:. But, here's the thing -- that coach had rear air bags and a compressor to adjust them, and it made absolutely no difference in the bouncing.

Not sure if they would help a Serenity or not, but I'll never have them again...
 
I have had Timbrens installed at all 4 corners of my 2013 Unity MB for over a year now and I am very happy with them. The Sprinter store installed the Koni reds in the rear last week and I am fairly happy with the rear end suspension performance now. I will install the Koni reds in front next.
 

Chip D

Chip D, 2013 Serenity
I have had Timbrens installed at all 4 corners of my 2013 Unity MB for over a year now and I am very happy with them. The Sprinter store installed the Koni reds in the rear last week and I am fairly happy with the rear end suspension performance now. I will install the Koni reds in front next.
While you were at the Sprinter Store, did you talk to them about the Glide Rite option? Seems interesting, but I like to wait for others here to jump into the water first.http://www.sprinter-source.com/forum/images/smilies/smirk.gif
 
They discussed the options with me...
The glide rite is outside of my budget, I also am not interested in air bags. I will do the front Koni's next, if I feel the handling is still in need of improvement it would be the sprinter store's extra rear sway bar to lock down the rear axle. That was there recommendation as the next step.
 

Sealanes

2015 Unity MB
Appreciate the comprehensive info on upgrades. Would appreciate comments on difference between Sumo-springs compared to spring assists offered by sprinter store. Do both accomplish same improvement in handling? Maybe need to go to different thread but has anyone upgraded brake system?
 

khaki8

Unity MB 2014
I have a 2014 Unity MB. I consider the original suspension on this almost incompetent from the factory. I can't believe you pay about $120K and get something so poor. The nose diving and the rock and rolling are really a problem.
I have installed the Koni's, the Helliwig sway bar and the Sumo Springs. It drives dramatically better and I now consider it competent even though it still does the rock and roll thing.
I bought the wheel spacers to make the tires further apart for the rears but at 1.5" there was no clearance so they had to go back.
I also had an upgraded sound system installed and had them dynamat the entire front compartment and doors. This helps interior noise a lot. I had the Sumo Springs installed after the audio upgrade and noticed that a big resonance was removed from the passenger compartment. You can no longer hear the diesel whine.
I love my van but am amazed they deliver them with suspension issues like this.
 

Old Crows

Calypso 2014 View Profile
I have a 2014 Unity MB. I consider the original suspension on this almost incompetent from the factory. I can't believe you pay about $120K and get something so poor. The nose diving and the rock and rolling are really a problem.
I have installed the Koni's, the Helliwig sway bar and the Sumo Springs. It drives dramatically better and I now consider it competent even though it still does the rock and roll thing.
I bought the wheel spacers to make the tires further apart for the rears but at 1.5" there was no clearance so they had to go back.
I also had an upgraded sound system installed and had them dynamat the entire front compartment and doors. This helps interior noise a lot. I had the Sumo Springs installed after the audio upgrade and noticed that a big resonance was removed from the passenger compartment. You can no longer hear the diesel whine.
I love my van but am amazed they deliver them with suspension issues like this.
And just what exactly did you expect from a 11,030 # GVWR, high center of gravity recreational vehicle????
 
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Old Crows

Calypso 2014 View Profile
Appreciate the comprehensive info on upgrades. Would appreciate comments on difference between Sumo-springs compared to spring assists offered by sprinter store. Do both accomplish same improvement in handling? Maybe need to go to different thread but has anyone upgraded brake system?
Can't speak to other upgrades. However, if you are wanting to control the side-to-side rolling and reduce the effects of gusts and passing trucks, the SUMO 'bump stop replacement' is the hot tip. Super Springs have renamed these boys "SOLO" springs. Cheapest fix there is.

They replace the OEM bumpers with ones that are in contact with the axles. They are made to resist compression and do not add any 'equal and opposite' reaction (like a sway bar) to the axle the root cause of the side to side rocking. Kills the body roll except in very extreme situations. Steadies the RV when you walk about inside. May add some road noise but it's not terrible and depends on the road surface.

How they work: http://supersprings.com/sumosprings_capacity.asp

For MB 3500's.... PN Rear: SSR-338-47; Front: SSF-106-40. Do call to make sure this is correct for your MY and TYPE.

FRONT: http://supersprings.com/images/SSF106.jpg
REAR: http://supersprings.com/images/SSR338_47.jpg

www.supersprings.com Ask for discount!

The cheapest, most effective add-on to kill rolling is for the rear. The front SOLOs do help but the abated rocking effect is most noticeable on the rear. The fronts keep the rear from acting like a 'hinge' causing the front to up & down on some surfaces. Do rear... try out.... add front if you wish.

ANOTHER POINT: It's important to recognize the effects of tire pressure on the ride and performance of the suspension. More pressure is not better!!!! contrary to 'school solutions' and what your GranPap said..... Let the driver's door TP placard be your guide. On my View Profile (3500 chassis) the recommended pressure is 61 PSI COLD F & R for MAX GVWR, 11,030#s. I'm guessing yours is the same. Here's why 61 PSI is best. There's no advantage going higher and higher pressures mean the sidewalls are less responsive and do not flex as designed. The suspension & tires are part of a well crafted team. You need that 'flex' in the tire wall to let the tire do the job it's designed to do....(besides holding air) and absorb much of the bumps, jolts, shocks, etc., etc.. The stiffer the tires are the less compliant the suspension and the worse the handling.

BRAKES! I wouldn't recommend screwing with the already excellent braking system you have on your Mercedes..... unless you want some very expensive repairs and make-overs... Its just not a good idea. Gotta remember is isn't a Porsche! The OEM brakes can haul that big boy down quickly from a good clip..... it's just going to take longer due to the weight. Drive accordingly....
 

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