We got a Kenwood Chef mod a901 as a gift but no
The parts that may require service after a very long tim would be the gear box which would require a clean out and refill with grease and the output shafts which can be wiped clean and given a touch if grease as well. The motor bearings could do with the same treatment and all this calls for a strip down of the mixer. However, if there is no perceptable play in the drives and no strange noises, the unit is possibly best left alone with just the minimum lubrication being applied as you intimate.
on Dec 12, 2011