Here are the circumstances:
>'09 E350 4Matic, 36K miles
>Cold, wintery, driving very slowly (5-6 mph) on a "wash board" street.
>The knocking sound sounded just like someone knocking their knuckles on a table top.
>The sound seemed to emanate from the left front suspension.

As we exited the neighborhood on to smooth local streets, the knocking sound stopped. But I think I may have heard it previously under similar conditions. This time it was very noticeable, even "the boss" could hear it.

Comments/thoughts will be appreciated.

relinuca

 

Actually, the road was paved but was covered mostly with about 6" of ice, except the spots where some salt had been randomly thrown down; hence, the wash board effect.

FWIW, I don't believe E-class' utilize torsion bars in the front suspension system, certainly not as a primary component, nor do they have shock absorbers per se though the McPherson-type struts within the double wishbone design perform a comparable function.

Your suggestion about a defective bushing is a good one as there are several points throughout the system with such wear-able items. Thanks.

relinuca