The sway bar end link joints may wear and cause a knocking noise over bumps. Loose or warn links should be replaced to correct this type of noise.Google+
Car Problem Reports
Mercedes-Benz CLK500 Worn Sway Bar Link Joints Causing Knocking Over Bumps
Mercedes-Benz CLK500 Problem
Average Mileage: 70,666 mi (50,000 mi - 90,000 mi)
I own a 2003 CLK500 Mercedes Benz and when driving over even the smallest bumps on the road and the bigger bumps you definitely hear the loud knock(noise)sounds like there is no cushion under there sort of speak. I have brand new tires all the way around the car. and this noise was happening even with the old tires on the car. Yeah, I mean the way they make some of these new parking lots it's almost like a small curb when entering the parking lot and I would have to go very slow upon approaching and going over it and I can still hear that clunk-knock-noise. I have not yet got it diagnosed or repaired,just trying to figure out what could be the problem before I bring it to the service shop so they don't try and rip me off.