The top reasons washing machines stop spinning include load imbalances, defective lid locks, broken motor couplers or belts, defective transmissions, and faulty water pumps. Some issues are more common in top-loading washing machines than in front-loading ones, or vice versa.
Before attemtping to diagnose a mechanical issue with a top-loading washing machine, first check to see if a load imbalance has been created by all of the clothes being on one side. This causes a washing machine to stop spinning even if no mechanical error is present. In this case, turning the washing machine off and re-balancing the load triggers the machine to begin spinning again once it is re-started. If too much water remains in the tub, it may be necessary to drain the washer first.
Another common non-mechanical reason that front-loading washing machines stop spinning is a clogged pump. The problem can usually be resolved by cleaning the trap. Once the water is drained, it may be necessary to re-start the machine.
If an imbalanced load is not the cause of the spin cycle stopping, then the issue may be mechanical. Mechanical causes for a washing machine to stop spinning include defective lid switches, broken couplers or belts, and timer malfunctions.