Expert: Sean Halliday - 11/25/2007

Question
I have a 1988 Mercedes 300SEL that makes a knocking sound in the front suspension on the drivers side. When I hit a bump in the road, it makes a loud knock like metal hitting metal. It makes the same noise when I step on the brakes- the anti-locks pulse and the noise happens with each pulse. I first thought the shock broke but it didn't.

Answer
With the age of the car,its most likely the upper and lower suspension arms/bushings which are worn or gone completely.Check also the outer tie rods and steering rack and pinion with the hydraulic arm for wear.Raise the front wheels and check the hub bearings for play up and down as well as noise when you turn the wheel.Although the shock looks ok,it may be worn out but its best to replace if you have lots of miles on the present ones especially the front on this car which is a heavy chasis and wears the shocks more over time.