I have a 2nd hand Kenwood. The Liquidiser screams when in use. I have dismantled the whole thing and tried just the base with the blade on the mixer with the same result. The other kenwood blender I have is fine (but doesn't have a handle)so I know the actual power unit is ok. Any ideas what the problem is? Or do i need to replace the blender base unit?

Heather, July 2011

It's probably the shaft bearing. I have one and I took it apart: the shaft showed some corrosion probably from liquid ingress and you can feel the friction in the shaft when you hand-turn the blades.
I lubricated the internal part of the shaft with oil and grease but it didn't last long. The resultant heat when you run the liquidiser causes the rubber/plastic drive (on the bottom) to debond. I have rebonded it well a few times but the heat generated from the bearing defeats it.
I have also bought (twice!) a replacement base online - it is a cheap plastic unit with removeable blades but the same thing happens! The plastic drive goes soft and it debonds from the metal shaft even though the shaft turns freely (i.e. bearing/shaft is good).
Maybe a brand new liquidiser is the answer- if the new ones are compatible.

John F, February 2012