I have a knocking noise in time with road speed (not engine revs) when I'm coasting or slowing down. But only when steering straight ahead. It stops when I turn the steering wheel slightly. Could anyone help me please with suggestions for the cause and/or how to investigate it.

Thank you.

Could be a few problems here but you will need to elimnate them one by one, start with the drop links, then move onto the anti roll bar rubber bushes next for me would be the wishbone/control arm rear bushes Quite popular problem you can see if these are torn or cracked cracked strut spring right at the top mount could be an issue, might be slight play in the bottom ball joint as well, strut top mounts have also been an issue most of these joints can be checked with a pry bar to strees the joints to see if there is any play, the spring is a visual spot a goood light up under the wing and a feel around the top fold of the spring, have even seen the front bearing come out with a clonking noise , just a few pointers but good liuck hope you can sort it out