Thor Mercedes Diesel Class C Sway Issue

BABBOTT · 09-15-2021, 12:23 AM

I am a new owner of the Class C Mercedes Diesel 3500, Citation 24SJ motor home and while we love the coach layout and detail, I am very disappointed in the sway from wind and large passing trucks

I understand this is an issue with a lot of motor homes from the website comments.

Guess my first question is where to start to minimize the sway? Roadmaster auxiliary rear sway bar? Hellwig upgrade front sway bar?

Any tips on where to purchase and have installed would be appreciated.

Bob Denman · 09-15-2021, 12:52 AM

SumoSprings will stop the sway...

I've got them on all 4 corners of mine!

Flwestcoast · 09-15-2021, 01:03 AM

I have the Quantum 24CR and agree the sway is not pleasant.

I’ve ordered Fox shocks for the rear and will decide after that if i need to do more. The new Mercedes chassis already has the heavier rear sway bar. I’ll look to options on front if this isn’t enough.

BABBOTT · 09-15-2021, 02:51 AM

Thanks for the help.

The summo springs are the rubber plates that go between the existing springs?

BABBOTT · 09-15-2021, 02:56 AM

It is my understanding Roadmaster makes an auxiliary rear sway bar that can be added to the present factory bar.
They also can supply a replacement sway bar. Your understanding is the replacement bar is not any stronger than the present factory bar?

Flwestcoast · 09-15-2021, 07:56 AM

Read this posting on other forum. I found this after I went under my coach and thought bar looked larger than what people were replacing. Very informative thread…

https://www.irv2.com/forums/f280/my-...on-478870.html

I google my questions with forum in the line so I’m not limited to just this forum for info.

Edit
Did you have your alighnment/toe/camber checked? I thought coach drove ok so I was shocked when I had mine done. I did a thread here on results. Ask Thor for goodwill reimbursement.

Bob Denman · 09-15-2021, 12:21 PM

Quote:

Originally Posted by BABBOTT

Thanks for the help.

The summo springs are the rubber plates that go between the existing springs?

Yes, and they do a really great job of reducing the amount of sway.
It's probably the easiest thing that you could try.

Flwestcoast · 09-15-2021, 12:32 PM

I looked up the auxiliary sway bar you referenced. I am sticking with the Fox shock option. I’m a couple months in on the back order log and will wait for those. I don’t like the mention of having to modify exhaust in the description of the sway bar plus I feel the OEM sway bar is sufficient for that aspect of sway. Everything I have found on the Fox shocks has been extremely positive. The mechanic at the shop that does my alignment said Fox were the best and I will love them… I will do those and re-evaluate after.

paulwadley · 09-15-2021, 12:41 PM

I added Summo Springs a couple of years ago to my 2018 Thor Siesta 24SS which is built on a 2017 MB Chassis. It solved the majority of the issue of side sway(going in and out of driveways and passing trucks on the road). They are very easy to self install and would be the first thing you should consider. They are called Summo Springs but actually just replace the MB factory bump stops from the frame to the chassis.

Paul

BABBOTT · 09-15-2021, 12:47 PM

From the web comments its hard to tell if the Hellwig replacement sway bars are actually heavier.
Have seen several positive comments about the sumo springs. Have you tried those on the rear.
I will look up the Fox shocks. Thanks for the help.

BABBOTT · 09-15-2021, 12:49 PM

Thanks Paul. I have looked up the install on u-tube and agree that should at least be the first option.

Flwestcoast · 09-15-2021, 03:22 PM

Quote:

Originally Posted by BABBOTT

From the web comments its hard to tell if the Hellwig replacement sway bars are actually heavier.
Have seen several positive comments about the sumo springs. Have you tried those on the rear.
I will look up the Fox shocks. Thanks for the help.

From what I have read it’s about .1 difference. Practically nothing IF you have the newer chassis. Mercedes also apparently fixed the bolt issue on new chassis. The cost is not worth doing that IMHO. But I spent a lot for the Fox shocks after all my research. I went for biggest bang. If I’m not happy I will do the sumos also. Agileoffroad.com

Since waitlist is about six months for Fox it would be good to do the sumos now vs nothing but I’m not that big of a rush and I’m not sure I could do the sumos myself to keep costs low. It’s about 225 to get shocks installed once I receive them. I’m not “auto mechanical” and at 115 pounds I don’t have the physical strength men do.☹️

Flwestcoast · 09-15-2021, 03:24 PM

Quote:

Originally Posted by paulwadley

I added Summo Springs a couple of years ago to my 2018 Thor Siesta 24SS which is built on a 2017 MB Chassis. It solved the majority of the issue of side sway(going in and out of driveways and passing trucks on the road). They are very easy to self install and would be the first thing you should consider. They are called Summo Springs but actually just replace the MB factory bump stops from the frame to the chassis.

Paul

Which sumos did you add in case I decide to add those also?

waynetaylor55 · 09-15-2021, 04:17 PM

First thing I did was get an alignment. that took care of 50% of my sway issues. I had a +5 caster adjustment made.

Next I replaced the factory front sway bar for a Roadmaster. Another 20% or more resolution to sway.

We are to embark on a 3000 mile trip. If I need anything else, I'll probably do Sumo Springs to help with the bounce.

paulwadley · 09-15-2021, 06:36 PM

I installed the SSR-338-47 Sumos to the rear and the SSF-106-40 Sumos to the front end. The rear ones slip into the factory bracket and the front ones have a threaded bolt that extends out of the top to hold it in place. I did remove the front wheel on each side to gain better access. I used my hydraulic levelers plus a stand alone bottle jack for safety.

Paul

KUDZU50 · 09-22-2021, 07:55 PM

I own a 2014 Citation 24SR and had an alignment done before I went on a trip to the Grand Canyon. Driving Hwy 89 from Flagstaff to the Canyon the wind was blowing & howling plus hundreds of tumbleweeds were hurtling across the road and hitting our motorhome. Real wild west. Had to stop twice to remove tumbleweeds from under RV. Off in the mountains we witnessed a huge wildfire. I really didn't sign up for this, but, it made for a unforgettable experience. Only bad thing that happened on that trip (which was my fault) was we lost a rear hub cap in New Mexico on the interstate. If anyone see it let me know.

I did experience a little sway, but for the wind speed felt the motorhome did an excellent job on the trip. Safe Travels!

paulwadley · 09-22-2021, 10:11 PM

KUDZU50 Sorry that you lost a wheel simulator(chrome hub cap). I lost one just over a year ago and replaced it for about $100.00. I then used zip ties to add security to each one to be sure that another does not fall off. I put 2 zip ties on each simulator attaching it to the rim.

Paul

You may also like: