If your Maytag top load washer is not agitating properly. In other words the washer fills properly, spins at the right speed, but the agitator is not moving fast enough to wash the clothes.
You will need to check the following parts until you find out the part that needs to be replace to fix the washing machine.
Here I am going to give you a brief description of the parts you need to check, and below you will have the links to the pages with the videos that will show you how the repairs are done.
The agitator: A stripped agitator spline could cause the agitator to turn too slow leaving the clothes dirty. This doesn't happened too often, but could happened.
The belts: This washer uses 2 belts. The motor to transmission belt is used to make the washer spin or agitate. The motor to pump belt is used to turn the pump to drain the water from the washer.
The age and the amount of time that you use the washer has to do with how fast the belts wear out. When the belts wear out, they tend to slip and grab the transmission pulley less ,slowing down the agitator action. The link below will show you how to remove and replace the belts.
The springs & slides: The motor is mounted on 2 metal plates that use 4 slides and 2 springs to give the belts the proper tension to agitate or spin the drum.
The metal plates mount one inside of the other and dirt sometimes prevent the springs from giving the motor the proper tension. The video on the link will show you how this repair is done.
The transmission: The oil on the older transmission could get thick when the washer is located on a place that gets cold. Thick oil will cause the gears in the transmission to turn too slow to wash the clothes at the right speed to clean it.
As you could see if any of these parts fails to work properly it could stop the washer from washing the clothes properly.