Writing this on behalf of my neighbours series 80 Kenmore Washer.
I’ve read a number of posts on this problem and I understand its rather difficult to diagnose when not being there and there could be a number of problems causing this but, thought I send my observations any way.
She put a few rags in to clean and apparently it doesn’t matter how much water or clothes are in the wash tub. Everything thing ran well until the spin cycle started and when it did it made a very loud clack clack sound. It was more defined as it started the spin cycle and softened slightly as the speed of the tub increased tho still very noticable. When the spin cycle completes there is a rather big bang bang as the tub slows and stops.
Aparently this just started out of the blue, one day it was fine and then not. I saw a video on how to remove the cabinet of the washer to get a closer view and see things more clearly, so I may do that next once I connect with my neighbour.
Thanks for all replies in advance. Maybe worth finding a good used one instead of repairing if its significant.
Cheers 
Jack