Mr.Biriggwa

Hello all,

First I must say I am more of a "lurker" than a poster, so I apologize in advance for my lack of engagement as a fellow E55 owner. I have been dealing with a rather strange issue while driving. According to previous posts here regarding the "rear end shimmy over bumps", many have resolved their issues by simply replacing all subframe bushings and calling it a day. I have been trying to figure this issue for around 8 months without any success. So here's a brief synopsis of what has happened and what i've done to attempt to fix the issue:

1. When accelerating from a stop with shift points between 2k-3k rpm the rear end seems loose and wants to break out to one side (to many of you that would indicate worn subframe bushings). I have been skeptical because all 4 subframe bushings are polyurethane and were installed 5 years ago. Is it possible that they are bad? IMO it is unlikely. Found that the original shocks were worn so I replaced them with Koni sports around 10k miles ago. That stiffened up the ride.

2. When going over bumps (after the shock installation) I noticed that my rear end was "skipped" to one side. So I thought that maybe something was wrong back there. Additionally, I would get the random weird tracking between 50-60 mph. The tracking seemed to be a front end issue at the time so I had the wheel bearings replaced as well as the LCA and bushings. That lessened the random "wobbly" feeling at speed, but by no means did it cure the problem. It was more like curing the wobble enough so that the ESP light didn't light up going around long bends at 80mph (I have since gone to target to replace my stable of underwear).

3. Now I am at a point to where i've replaced the LCA and bushings, front wheel bearings, suspension at all four corners, I still have this problem. This problem does not seem to be tire specific either (I have had continental dws, and just replaced the rears with the Pilot Sports A/S). The funny thing is that when I let of the gas at around 40mph the car does this weird tracking thing that I can best describe as going over pavement with ridges and it messes with your steering.

Some things to note:

the technician says the transmission mount is worn, but doesn't see it affecting the drivability of the car in the manner that I have experienced. He also said that I had a "used" knuckle on my front left side (made me a little skeptical).

I am currently running renntech springs with the Koni sport shocks (yellows).

The only other thing I can think of (after a few fingers of whiskey) is that perhaps I need to replace my renntech springs with H&R springs.

I am at a loss and the technicians at the dealer are at a loss as well. They were very frank with me in the things that they looked for and were hesistant to really dig deep because it could get expensive for a problem that is not readily obvious. So perhaps you gentlemen/ladies (if there are any) could shine some light, I would be ever so grateful. If you feel I've left any details out I would be happy to provide as much as I know.

P.S. I feel like i'm writing a "Dear Abby" Letter about my car

A Hopelessly "in love" E55 owner LOL

tsquare

I am not certain by any means, but I think your problem is the Poly Bushings that are in the rear. I remember reading about some issues similar to yours regarding the use of poly bushings.

You might want to google for possible links regarding poly bushings.

Good luck

timmins

My car suffers from similar behavior, particularly the "skipping out" of the rear end over some bumps. I also find that the car wanders a little at highway speed, and tends to need constant steering correction.

I replaced the sway bar bushings and links, got new tires, and had an alignment performed. The problem is either slightly better, or I've just got used to it. I can't imagine this is a characteristic of the car, it just doesn't feel stable enough for a high-speed sedan.

Sorry I can't offer any solution, but I feel your pain.

RustbucketRacer

My buddy had a similar effect on his car. He ran RennTech springs with stock shocks. He also replaced all that yoU (OP) mentioned. The problem only went away when he went back to a stock E55 spring and number 1 pad.
In hindsight, maybe he just needed camber links in the rear.
I have my stock springs if you want to try them out and see if it goes away. I'm in SoCal.

vincentie

i have the same problem, kinda gave up trying to find out the reason, i also have gotten used to it,only difference is it doesnt kick to one side like you say though , it just a wiggle over bumps , changed out a lot of new parts and its still there , i am running bilstein sports with ebach springs always thought that maybee the ebach springs might be for the regular e class and not the e55, i never got around to changing them though ! i got camber adjusters back there so i dont think its a camber issue either