Slight knocking sounds

[Capra]

I get this slight mechanical knocking sound, but only very slightly when I reverse the car up the drive, made worse if the front wheels are not straight. Not helped by the curb being slightly raised which means the movement is made worse and not very smooth. It also does this when I reverse off the drive and have the wheel nearly on full lock to turn in the road. Going forward is always fine.

 

[KennyN]

Sounds like a worn ball joint/ drop link somewhere within the front suspension area.

If you are close to MOT time than just leave it and the tester will find it or if the MOT is a while away then get it into a trusted garage for a check,

So many variables with MB`s complex setup to even try and point you in any direction.

Kenny

 

[alexanderfoti]

Could also be the tyres skipping, Lots of 204's do this on full lock, and its more apparent with colder temps/stiffer tyres. They essentially do this:

Although not as dramatic.

 

[Capra]

Could also be the tyres skipping, Lots of 204's do this on full lock, and its more apparent with colder temps/stiffer tyres. They essentially do this:

Although not as dramatic.

Thanks for this, it does happen when the car is manoeuvred like this, and only happens on near to full lock. The MOT was last month and there were no advisories at the time.

 

[Jimbo1959]

Is it only the 204's that are known to do this?
My C207 makes a similar noise intermittently, in exactly the same circumstances, when I'm reversing out of the driveway on full lock.
I've had it into my guy at the garage a couple of times but struggled to reproduce the effect when we wanted it.
He checked the suspension out and could find nothing amiss at all.
It's been very puzzling, and this would certainly explain it.
More to the point, does anyone know what causes it or is it just a characteristic of the car?

 

[LostKiwi]

More to the point, does anyone know what causes it or is it just a characteristic of the car?

It's a characteristic of the suspension design. High caster angles plus large lock angles and as a result compromised Ackerman angles (which are always a compromise anyway).

 

[Capra]

It's a characteristic of the suspension design. High caster angles plus large lock angles and as a result compromised Ackerman angles (which are always a compromise anyway).

If I had some worn components (worn ball joint/ drop link) as mentioned before, but this be more obvious in day to day driving?

 

[LostKiwi]

If I had some worn components (worn ball joint/ drop link) as mentioned before, but this be more obvious in day to day driving?

Worn components will aggravate any noise but if the tyre slips on the road surface as a result of the compromised Ackerman angles it can be noisy even if all components are perfect.
Noises away from full lock won't be down to this - as the lock decreases the effect of Ackerman angles reduces.

 

[JBell]

Is it only the 204's that are known to do this?
My C207 makes a similar noise intermittently, in exactly the same circumstances, when I'm reversing out of the driveway on full lock.

Same chassis