Knocking sound

[Marcus28]

Hi.

I'll try to detail as much as I can for a knocking sound I have and I'm looking for possible causes. It's a 2006 ford s max.

1.   When stationary and the engine is off it knocks when moving steering wheel back and forth and when engine is on so the power steering is obviously functioning it don't knock but almost has a grinding sound.

2.   It only happens when either stationary or slow manoeuvres such as in a car park. When I'm at speed even as much as just 20mph and over I can't hear it in cornering or straight lines.

3.   It has been to the garage for this and they replaced the track rod ends and a missing sub frame bolt and it has not fixed it to eliminate those.

4.  In my opinion it's the drive shafts/ CV joints. Hopefully nothing to do with steering rack etc.

Thanks in advance for advice.

Marcus