Many chemicals both in the detergents and possibly in water can cause damages to the machine. There are some other problems like hosepipes or other fittings getting loosened in the course of time. Improper electrical connections can also cause damages to the machine. No one can predict the problems that may occur due to moisture, heat, chemicals and electricity. Overloading of clothes also can cause damage to the machine.
Breaking down of your washing machine when it is most needed is really painful and the things become even more disturbing when you don't have any idea about its different spare parts. So it is really important to have complete knowledge about your appliance. Your little awareness about the washing machine will save you from those tough times, helping you to fix it on a temporary basis.