How is the drum attached to the shaft in front loading machines

You have the problem. Replace the pulley. Here is the part to order.

With the washer empty, spin the wash tub by hand. The drum should be spin true without any noticeable wobbling and spin without much noise. If it wobbles or makes any kind of rubbing or banging noise as you turn it by hand. The problem is that the spider support arms are broken. It is an expensive repair job since the washer has to be completely torn apart and the wash drum needs to be replaced. Get a few estimates before deciding whether to repair or replace. Sorry.

Are the two pulleys lined up with each other? Is the belt tight when installed? Make sure the motor is firmly attached at it's mounting. Is the drum or motor pulley hard to turn by hand? Make sure that neither pulley is wobbling or loose on it's shaft. Hope that some of this helps!

Check the suspending springs inside. These are attached to to the drum jacket. If the springs are OK check whether the drum is wobbling. Turn by hand and check. Check ball bearings last!!!

Use a rubber mallet or an oak block to cushion the hammer blows. Be careful not to bend the shaft or your drum will wobble. Also don't ding the spline on the shaft.

Could be loose bolt @ back of pulley or Drum bearing gone which makes drum very noisy on spin expensive to fix..

sounds like the drum is loose. remove softener dispenser, usually a plastic hand nut, then you should see the drum nut, may be under softener goop though. check if tight. other thing could be one of the drum stabilizers broke, usually drum has 4 of them attaching drum to dryer frame. place unit on side and check

Sounds like drum bearings?? not for the faint hearted! could cost around 100 to get engineer to repair.

go buy new washer the drum bearings have gone and it really is not worth repairing . it can be repaired but always found that it never lasts long once done.

your drum shaft is broken this is making the pulley wobble causing the belt to come off and it will also explain the noise. This is a very expensive job sometimes requiring the complete tub to be changed might be time for a new machine