I looked up your model number and your washer is a direct drive washer that has been manufactured by Whirlpool for sears.
You could have something stuck in the water pump or you could have a problem with the motor.
I would remove the cabinet and unclip the water pump from the motor, but leave the water hoses connected to the water pump being the washer is still full of water.
Take a big flat blade screw drive and see if you can turn the pump by hand, like the motor would turn it. If should be able to tell if the pump moves free or if something is stuck in it.
This topic has a video that shows you how to remove the water pump.http://appliancejunk.com/forums/index.php?topic=6346.0
The other videos in the topic also relate to your washer too.
Let us know what you find or if you have any other questions.