The brief
Mr Delson's E200 had a weird noise when crossing humps, a knock and a creak from the front over bumps and uneven roads. He brought it in. That kind of noise over humps usually means the anti-roll bar links. The anti-roll bar runs across the front and ties the two sides of the suspension together so the car leans less in corners, and the links are the short rods with ball joints and bushings connecting that bar to the suspension. The joints wear and the bushings crack, so over a hump the link works loose and knocks or creaks, and the anti-roll bar can't do its job cleanly. A worn link only knocks louder, and it puts strain on the parts around it, so they need changing.
The diagnosis
On the lift the front suspension got the once-over. The anti-roll bar links were the culprit, the ball joints worn with play you could feel by hand and the bushings cracked, which is exactly what makes that knock and creak over humps. The rest of the front, the arms, the bushes, the shocks, checked out. When the links on an axle have gone, you do the pair, they wear at much the same rate, and a fresh one next to a worn one just means you're back under there soon for the other side.
The work
Both front anti-roll bar links were unbolted and removed, and a new pair of genuine Mercedes-spec links fitted, the ball joints torqued to the manual figures and seated properly, the fresh bushings checked. The rest of the front suspension was given a final check while everything was accessible. A road test confirmed the knock and the creak were gone, the front end quiet and tight over humps and through corners.
The outcome
No more weird noise crossing humps, the anti-roll bar working properly again, and the car flat and composed through corners. The E200 went home with the noise sorted. Worn anti-roll bar links only knock louder and put strain on the parts around them, so doing the pair put the front end back to quiet, the small job that protects the bigger ones.
