TheInfuse

Does anyone know what would cause the rear end of my car to feel like it jumps or jolts from side to side over large bumps and potholes?
I've driven many cars and never before experienced this feeling going over bumps. The best way I can describe it is that it feels like the rear wheels skip out a few inches over every bump.
I'm not sure if this is the tires bouncing on the pavement due to less suspension travel or if it is just some issue with my setup. The car drives fine in every other aspect and in fact rides amazingly as long as you don't hit any decent bumps.
I've done some searching online and I can't find any reliable info as it seems to be caused by a number of different things. Is there anyone out there who has dealt with this issue and has any advice? Should I change my tire pressures?

Info for reference:
2010 E350 W212 All stock except for Rims & Springs
Lowered on H&R springs
20" Vossen CV3R front and back (Just recently balanced)
Front Offset 40
Rear Offset 50
Tires are Michelin Pilot Sport and Super Sport
Front tires 245/35ZR20 (35 PSI)
Rear Tires 275/35ZR20 (40 PSI)

The G Man

Looking at your setup, I would start with the springs.

KEY08

its because you are lowered. How ghetto is it?

Abrown3mtg

It's most likely an alignment issue and likely induced by lowering. When you drop a car, you alter the chamber. Having the chamber thrown off, you will feel far less sure footed due to a smaller contact patch on the tires. I have experienced similar sensations in vehicles (including my w212) as well. How many miles are on your vehicle? Worn suspension components could result in similar symptoms.

The G Man

Also, your rear wheel diameter is about 1" bigger than the front. It a good thing you don't have 4matic. The different diameter must do wonders for your stability system. You might want to change the rear tires to 30 aspect ratio.

belarus27

does the same principal applies to airmatic? cuz i was thinking lowering mine a bit due to extra floaty effect

blegthbloo

When I put my springs on, I had it checked a few times (A/B service, misc checks, etc) from various people and they all reported the alignment was good... don't ask me how, but I can't argue with people who do this every day. I'd say it's probably worn components.

Diesel #2

It feels like i have been commenting on a lot of tire size threads lately lol. Ok one more, I am sure those sizes are wrong, there is no way you can run 275/35/20 in the rears. I dont think you can fit 245/35 in the front either. Your sizes are more than likely 235/35/20 and 275/30/20.

As to the "jumping around" of the rear, sounds like a suspension problem.

TheInfuse

Sorry for the late response as I've been working all day..

As for the tire sizes they are absolutely correct. I just double checked to confirm.
Also, it is not a 4Matic. Just a standard RWD model. No Air components in the suspension that i know of either. I don't have any problems with the setup other than this one issue

As far as the suspension components, everything looks good to the eye but I would probably need to get some in depth checks done to be sure. All bushings appear to be in tact and nothing appears worn or damaged. The tire wear is even and doesn't seem to be wearing the tires unevenly that i have noticed over the last 8,000 miles.

What do you mean "how ghetto is it"? I was assuming the performance springs made for this car would improve the handling to some extent. Maybe the springs were not the best route to go but the previous owner installed them and now I'm dealing with it lol

Diesel #2

Is 5 mintues of your time worth $50 ? I am not saying i do not believe you but can you snap photos of those sizes of the rear and front on your car ? if so, i will forward you $50 through paypal. Again, im not saying you are wrong but i need to see it to believe because my rear wheel are 26.4" and they rub if i go over speed bumps quickly so it is hard to believe your rear sizes are 27.6".

TheInfuse

lol of course for you I will!! Give me a second to take the pics and post

TheInfuse

Here is the tire proof lol
My Paypal is Byteknightrepair@gmail.com

TheInfuse

I don't have any issues with scrubbing except under the most extreme circumstances. If I've got a full tank of gas, 3 passengers, and I hit a large dip in the road the rear tires will scrub slightly. Never had any issues in the front. The rear scrub has only happened to me a couple times in the last 8,000 miles.

The rims are brand new and were just replaced by Vossen under warranty. I was hoping their new CV3-R series were the exact same offsets. They were not. My original rims were 55 rear and 44 front offset whereas the new rims are only available in a 40 and 50 offset.

Diesel #2

The proof is in the pudding. Thank you.

Money sent, buy yourself some tire shine, just kidding bro. Thanks again your post was very useful to me.

This leads to be wonder if the front perch location on the 2010 is located higher than the 2016. Because i have 235/40/19 tires up front and i can barely fit a few pieces of paper between the tires and the perch, but your tires are more than 1" larger than mine. But i guess it can be done. Do you have a lot of negative camber?

TheInfuse

Well Damn I honestly didn't expect you to be serious lol. Now I feel bad for taking your money..

As far as the perch there must be some difference because I've got almost half an inch clearance between tire and perch. I've seen on other posts and forums where others had my same size and the tire was torn apart by rubbing the perch and after that I made sure to keep a close eye on mine. So far it hasn't even come close to touching the perch.
As far as the camber it should be extremely close to 0. All of the wheels appear perfectly vertical to the naked eye.

The G Man

Sounds like your suspension is so stiff that you are losing tire contact every time you hit a bump thus causing the car to skip.

KEY08

^agreed, and my comment about the ghetto stance is how low did the previous owner go? Something is wrong with the setup/springs. Your shocks are not allowed to rebound and cushion the bumps. You've seen those really lowered ricers going down the street and bobbing up and down like a damn rabbit? I think you are suffering from a poorly engineered suspension setup by the previous owner, and it is way too stiff.

TheInfuse

This is what I'm fearing too but nothing drastic has been done other than installing the H&R Springs. I can adjust my side view mirror to see the rear wheel while driving and it has a decent amount of suspension travel. To me it looks like more travel than you would get with a coilover setup. If i really am losing tire contact I would be surprised because the suspension really isn't super stiff. The ride is still comparable with stock springs

The G Man

With your 275 summer tires, there is no way you would be skipping over bumps unless you are losing tire contact. The cause might not be the stiffness of the suspension but it is the result of not having a full tire contact patch. Another possible issue is that you have increase the diameter of the rear wheel by 2" over the OEM set up, you must bottom out a lot, if not, your suspension must be as hard as a rock. Did the last owner change the wheel offset, that will affect the alignment. This is one of the reason why I stay away from modified used cars, its just another headache I do not need.

Diesel #2

Hey no need to feel bad, you didnt take it, i gave it.

I too was lowered on H & R springs, no issues. How long have your springs been installed ? Your shocks might be worn out from the lowering springs. Have you had anyone check out your suspension components ?

TheInfuse

Springs have been installed as long as I have owned the vehicle so I don't know the exact answer to that question. My suspension components have not been checked professionally but I was just under the car recently and visually inspected everything I could front and back. I didn't see any components that appeared to be worn. Everything looks fairly new so that's why I am wondering if there is maybe something I'm missing that I need to add to this setup or If it's just flat out wrong in some way.

I should be able to install those springs without causing more suspension problems right? or am I missing something here?

TheInfuse

It's hard to picture these tires not having a full contact patch because there is no camber and these are some pretty wide tires.
Also It never bottoms out. The rear tires will lightly scrub over very large dips or bumps in the road but I've never felt the suspension bottom out in the front or back. Like I said before the suspension feels stiffer than stock of course but in my opinion it's actually still quite comfortable. I've ridden in vehicles with coilovers that were far worse

K-Mac

Do point out to reduce rear end flex / twitch especially when applying power lane changing / overtaking we manufacture uprated bushings (12) for the ‘6’ rear multi link arms. Noticeably improving, stability, vehicle control.

There is only Front and Rear basic “Toe” adjustment OEM therefore we also manufacture and have reinstated from the early ’90’s “precisely adjustable” Rear Camber (and extra Toe), Front Camber and Caster kits.

Allowing to “change tire contact angle’ to cater for conditions encounted with day to day commuting - high cambered roads, load carrying, altering height, fitting wide profile tires, suspension sag, curb knock damage and correctly resolving steering pull.

Kits replace the 4 highest wearing front and rear bushings at the same time.

Front bushings are 2 axis / self aligning without the OEM oil and air voids. Result is also significant improvement to brake and steering response.

Rear 12 link bush kit #502628 K $480-
Rear Camber (and extra Toe) kit #502226 K $480-
Front Camber and Caster kit #502916 K $480-

(Also manufactured front replacement top strut mounts for coil spring models - also precisely Camber and Caster adjustable available in Stage 2 (Street / Race) #502916-2 L $545- Stage 3 (Full Race) #502916-3 L $545-

Delivery $30 one kit $20 each additional kit.

Accept PayPal, Visa, M/Card

TheInfuse

So these kits are just upgraded bushings and that alone might solve this issue? I'm willing to replace all the rear bushings if that's really what's causing my problem.. I just want to be sure before I spend that much.

ddcarter3

So, I have a 2016 E350 CPO. At ~18,000 miles, I took my car the MB of Austin. I asked the Service Adviser to take a ride with me to feel this same issue. Mine is all stock. I was told it is the rear tires. I found this hard to believe. I drive a lot of highway miles and complained that the tires shouldn't be that worn. He said it is a RWD car. I asked him how old did he think I am (55)?? I grew up on RWD cars. My other vehicle is a 2001 F250 7.3 RWD truck!! They would not back off. I bought 2 rear tires after a white knuckle ride from Austin to Houston. I am now approaching 40k and the rear end is stepping out again!
This seems to be a design flaw!!
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