Indesit WG1034T Washing Machine - Knocking sound?

Hi,

I have a Indesit WG1034T Washing Machine. Until now, we have had absolutely no problems. It is quite old, around 9 years I believe. (please don't say buy a new one).

When the machine is spinning, like a normal spin it makes a knocking sound, the faster it spins, the faster the noise gets.

When it is spinning really fast (super spin), the noise is not heard.

It makes the knocking sound with or without clothes loaded.

I do not have a clue as to what could be wrong, please could anybody advise me further on what to do, regarding parts, fitting..etc.

If any further information is require, please let me know

Thank you.

Jas