[Kenwood] stiff drive control

[Neil]

Hey Kenwood'ers,

The 'Drive' control on my 520 is stiff as a snake at the
South Pole. 

I've had the top cover off, doused the drive chains and
variable cap sections, and bearing, with a reasonably good
electronic parts lube and cleaner, to no avail. Really hard
to adjust. I'm thinking of putting a larger diameter knob on
the shaft, even though that will completely blow this
beauty's fine looks.

I haven't been into the 6146's living room yet. Is there
anything in there that might need attention? I suppose the
plate tuning cap is hiding within...

Is this a common problem with this model?

Much thanks, Neil KH6EAM