steering column knocking over spped bumps, SL55

[RattlerRattler]

There's a distinctive knocking in the steering column when driving slowly over speed humps, I've not sensed this any other time, maybe it's the relatively slow speed and direct / even pressure on both front suspension that's causing this?

I've tried a search here but found little info. Is this a known issue on r230s or even is it the suspension?
TIA
Tim

 

[Alps]

lower front arm?, get it on a ramp probably a bush needs replacing somewhere

 

[RattlerRattler]

Thanks, she was only MoTd a few weeks ago, would this likely to be picked up then?