AMG Sway Bar on E350 Sport

A fellow Mercedes-Benz enthusiast, Jerry, asked us a question about replacing the sway bar on a 2006 E350 Sport with a sway bar from the AMG E55. That question brings up several considerations.  Here’s Jerry’s original question:

Subject: 2006 E350 Sport Sway Bar Replacement
I am looking to upgrade the sway bar in my E350 sport 2006,  the car has a tendency to roll to much going into corners.  I was wondering if switching to a 2006 E55 AMG sway bar would improve this roll.  Or if you have any other suggestions to make the car handle better but not bounce down the road.  Thanks in advance. – Jerry

There are several issues here to consider before making this type of modification to your suspension system. So, we asked our colleague John Olson, which has been custom building springs for SL’s for a decade or so. Here’s John’s response:

  1. Confirm that the E 55 AMG’s front and rear anti-sway bars are thicker (anything 2+ mm thicker would be noticeable). The change would reduce body roll. The stiffness increases logarithmically with minor changes.  Most “tuning” for cars occurs in 2 mm increments between 19 mm and 25 mm. Too big a change can unduly stress the brackets holding the bars. If the E 55 diameter is thicker, check for a difference in bracket part numbers too.
  2. The thickness of anti-sway bars is not always identified and differences in parts numbers could be other reasons. Consequently, have the thickness of your bars and a local E 55 measured with a micrometer before ordering.
  3. If the E 55 is 2+ mm greater front and rear… replace both, or you will concurrently alter the over-steer/under-steer behavior without motive.

Anti-sway bars and shock absorbers do not reduce coil spring travel, nose dive, or other behavior that is the job of the springs. 75 to 80% of the shock absorbers’ “job” is muting rebound, not compression. After changing anti-sway bars, if you decide there is still too much travel in your suspension system, progressive or sport springs would be the next step. The springs we make are not harsh but would definitely control the car’s weight better.  – John Olson (www.slmarket.com).

It is a quick check to assess whether the modification is appropriate for the vehicle. Keep in mind that the original parts were designed by engineers based on several factors; rarely just one. Often you can obtain feedback for common modifications but, if uncommon, the mods can have unanticipated consequences.

Post Author: Greg Magnus

One thought on “AMG Sway Bar on E350 Sport

  • Greg Magnus

    (June 22, 2010 - 3:52 pm)

    Jerry said he just came back from his local MB dealer and they looked up the sway bar. The E350 sport and the AMG 55 use the same sway bar; same part number.

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