Washing machines don't usually run silently, but in most cases, a squeaking noise that occurs while the washer is agitating the clothing is not normal and signifies a problem. If the noise only happens when the washing is agitating, the problem is likely connected to the motor or your water pressure. Depending on the specific cause, you may feel comfortable fixing it yourself. Otherwise, call a professional.
Agitators are located in the center of the drum, or basket, of top-load washing machines. Front loading washing machines do not use agitators -- instead, gravity moves the clothes from the top of the drum to the bottom. Agitators usually consist of a tall cone fitted with arms at the base. The purpose of the agitator is to rotate the clothes and soapy water around the tub to clean the clothes. The agitator itself is not usually the cause of the squeaking noise. It is powered by the drive mechanism, which consists of a motor, clutch and gears.
A repetitive squeaking noise during the agitation cycle may signify a problem with the motor. Specifically, the belt on the motor may be wearing out. Some motors use rubber couplers, which also wear out easily. The belt is necessary for the agitator to turn, but over time, it wears thin, just like the belts in your car's motor. An easy way to test for this problem -- if you're handy -- is to take the belt off the motor and then run it. If the squeaking noise stops, the problem is indeed your belt. Of course, this means your agitator won't move. Replacing the belt should fix the problem.
Water Pressure Issues
The tub, or drum, fills with water right before the agitator turns on, and water continues to circulate throughout the washing process. As the tub fills and water circulates, you may hear a squeaking or squealing noise if you have high water pressure. This sound is caused by the force of the water moving through the pipes. To adjust this, turn the knobs on the hot and cold valves on the pipes that go into your washing machine.
New washing machines may squeak at first as the parts "warm up," according to the GE Appliances website. The noise should disappear after five complete washing cycles have run on the machine. Unbalanced loads, overly heavy loads and loose items in the drum may also cause noise when the agitator comes on, but these things usually do not produce a squeaking sound.