Hotpoint WML520P

Hi
I was called to this unit about a month ago as it was noisy. found bearings gone and replaced tub assy.
got a call 2 weeks later to say it was still noisy. On inspection I found that it would start to make knocking noise on high end spin with load in. This noise would be amplified if you pressed lightly on upper concrete weight. after checking everything was tight I put it down to a fault in the new drum.
Changed the tub assembly but the same problem still persists.
The upper springs are in the correct locations which you can see from the marks in cabinet and the suspension legs are fitted into the rear 2 holes of drum each side.
what am I missing??
Has anyone had this issue before?

Geoff