Recently bought this mixer, which seems to work fine, but it sounds like something is not right, see link:

http://www.youtube.com/watch?v=naspqEkqK7c

Markus, October 2009

Ok, thanks. Is there an instruction for disassembly somewhere?

Markus, November 2009

I have seen the vid and can't quite work out the cause of the noise you have - it will either be the gearing or the motor - disassembly and inspection may be your best way forward. Years ago my mother's machine broke down - a nylon gear set had lost a couple of teeth - kenwood kindly sent replacements "cash on delivery" - so trusting of them. Excellent customer service.

Over time powder from icing sugar and flour gets inside - it may benefit from a good internal clean up.

Good luck...

Peccavi, October 2009