Why does the top agitator not move and the washer stops?
the washer fills but the top agitator doesn't work and the machine shuts down in mid wash.
Agitator Repair Kit
If the washer won't agitate this agitator repair kit may solve the problem. The kit contains the components that wear out over time. This is a relatively easy repair.
Drive Block or Bell
If the washer won't agitate the drive block or bell might be worn out or broken. The drive block connects the washer transmission to the agitator, if it's worn out the transmission shaft will still move back and forth but the agitator will either stay still or move slightly.