[PS Volunteer - Appguy]

Just verify the feet are all touching the floor.
It is normal for the tranny to start vibrating a bit after years of operation, nothing to worry about, I see it all the time!

[bettyboop]

You could try this, go to a washer bone yard in your area, buy a used spin basket like yours, take it home, see if it helps. If you lived near by I've a dozen you could have. shipping would be rediculas.Bettyboop (in florida)

[PS Volunteer - Appguy]

For insurance reasons the bone yard will not let you in. In this city we have a few major appliance stores and there is at least one who will let you pull off parts from junked washers, just ask. Really not in their best interest for them to help, but if you look poor enough they will realize you are not going to buy a new one from them.
Also I have never seen vibration from a bad spin basket and never saw a counter balance leak fluid.