Apparently soap and other stuff works it's way onto the shaft and over time solidifies and essentially glues the drum to the drive shaft.
There were a lot of opinions online but what worked for me was a spray to free rusted parts - multiple applications - boiling water poured around the rim of the shaft and then finally pulling, shaking from side to side and pulling at the same time until it finally released.
My second friction point was that the inner wash spin basket was froze to the Gear-case spindle and would not budge as there was much wash residue and oxidation on the gear-case spindle.
An overpriced tool can be bought to remove the basket if yours does not pull out freely. This is my experience with belt-driven Cabrio machine, problem started about 3 years after purchase.
At the same time, the additional torque load and vibration cause the retaining nut to work loose, and the cam pulley itself migrates downward.
As less of its splined core is engaged by the basket drive shaft, and the pulley wobbles.
In completing the repair I had to remove quite a few pieces of hardware in order to get at the part I was to replace.