You should inspect your W210 Upper front spring perch for any rust. If you
see flaking or really rough undercoating by your upper spring perch, chances
you got rust. Also inspect the joint between the upper spring perch and the
body. There should be mastic filler (chaulk)... that might be falling out...
if so, you also got rust there.
Inspect your front springs on the bottom... on the lower control arm. Look
for a crack within 5" of the end of the coil. If you got a crack, chances
are you got broken springs.
Rear springs are not an issue.
I recently worked on my folk's 2001 E320. One front spring snapped while we
were working on sway bar links and sprung out. Thankfully, it didn't kill my
friend. I was working on it only a few minutes earlier. So we decided to
change all the springs to Eibach Pro Kit.
The second front spring was already broken when we compressed the spring to
We also had complete rust through on driver side upper spring perch weld...
only 50% of the weld was left but that's like 75% of strength is gone. Had
MB repaired it for $800 for one side.
With new upper control arms, all 4 sway bar links, dealers replaced lower
ball joint a while back and new Eibach Springs, the handling performance has
increased tremendously. The car now steers like a go cart with almost same
ride quality if not smoother. Very slightly firmer that is only apparent on
harder bumps but not rough at all... I'd classify it more Euro handling
rather than mushy ride of stock.
Understeers are all eliminated.