Samsung Washing Machine makes loud dabka dabka noise while spinning?

I have a Samsung P10 washing machine which is 8 years old.
This makes loud noise when spinning. Noise is not continuous
instead happens at intervals. When I touch the stationery
drum from inside, it seems to be bending forward. Motor and
belt are fine. I had a look at the service manual, I suspect
the flange shaft. The samsung service engineer says the whole
drum should be replaced (50% of the cost of the machine).

Any ideas ?