normal noises for a HOOVER Dynamic Next DX C9DG ?

so I got a used HOOVER Dynamic Next DX C9DG the other day pretty happy with it on the whole stripped it down give it a good hoover out inside – even took the drum out to go all the way and clean fluff off the rear NTC sensor and the fluff out of the condenser float.
but what should the dryer sound like when its on and the drum is turning? – because I am getting a tap , tap , tap sound (a bit like a machine gun) when the drum is turning clockwise – and a vibrating/graunchy noise when the drum is turning anti-clockwise. I traced it down to the 2 belt tensioner pulleys. Do they normally give trouble on this model tumble dryer? – I sprayed some WD40 around the pulley area making sure I didnt get any on the drum belt itself and the sound has greatly been reduced but its still there a bit the machine gun (ticking now) on clockwise and vibrating on anticlockwise, the perfectionist in me wants to see if I can get it even quieter in operation so any ideas welcome please , if not i will just put up with the noise level it is now.

On another not (but maybe connected to the noise) I took a photo of the fan from the front of the machine (after removing the cover) and to me the fan does not look like it sits ‘central’ in its hole, it looks a bit too the left. here is picture (got to send a url link to the pic because I seem to be over my limit/quota for media on white goods forum) :

https://i.ibb.co/L9ZqHFd/95064249-174620500415679-2122604616146223104-n.jpg

I see there are 2 bolts under the plastic base of dryer where the motor is, is it possible they can be undone and just shift the motor so that it can get the spindled and fan centralised there . The graunchy and tapping sound is not coming from the fan rubbing in its hole by the way, its definately coming from the brown pulleys themselves. And the drum rear bearing and 2 rubber wheels at the front of the drum are A1 condition so its not them causing the sounds. Just the pulleys making the noise.

Any ideas please? – many thanks.