Dryer drum belt, length 88.75" x width 1/4". If the drum does not turn, but you can hear the motor running then there is a good chance the belt has broken.
Washing machine drain pump. On some models you will need to configure the replacement pump to match the old pumps outlet port direction and reuse the old mounting bracket. If the washer does not drain then the drain pump may be clogged, damaged, or defective.
Water inlet valve. The water inlet valve opens to allow hot, cold or warm water to enter the washing machine. If the water inlet valve is defective, the washer may fill slowly or not fill at all.
Washer replacement transmission kit. If the washer does not agitate, but the motor and belt engage the tranmission then the tranmission has likely failed.