Indesit W103 Banging during wash cycle

[Plymouth_Monkey]

Hi,
I have an Indesit W103 (UK) and the machine is making banging noises during the wash cycle as if the drum was loose and is banging against the chassis, any ideas as to what may be causing it, the drum rotates manually without any noise and from this I am assuming that the bearings are ok, there seems to be no obvious problem on inspecting the inside of the machine and I am at a lose to find out what is causing this. the banging does not occur on spin cycles only on the slow loosing off the clothes between the main cycles, any help would be greatly appreciated

 

[Sleepyhead]

Check the concrete weights, especially the one on the front. They may have come loose.
Failing that it could be a broken spider leg on the rear of the inner drum.