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Mercedes-Benz C-Class suspension knock

My Mercedes-Benz C-Class has developed a front end 'knock' from the passenger side when driving over irregularities in the road, such as potholes, at low speeds. In the past eight months the car has had the drop-links replaced (both) and lower control arms replaced (both).

The MoT two months ago failed to pick anything up and it passed. However, the knock has got noticeably worse in recent weeks. Any ideas what could be causing it?

Asked on 9 November 2016 by Michael Neill

Answered by Honest John
Front suspension perches have a nasty habit of collapsing due to rust. A spring could have broken at the lower end. Or it could be something very simple like a sleeve bush dropped out of the anti roll bar U shackle.
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