A washing machine that runs quietly through most of the cycle but suddenly starts vibrating loudly during the last minute of spinning is showing a very specific mechanical pattern. This timing matters. The final phase of the spin cycle reaches maximum drum speed, and even small defects that stay unnoticed earlier begin to surface under peak load.
When this happens repeatedly, the issue is rarely random. It usually points to instability in the drum support system or reduced ability of the machine to balance high-speed rotation.