My kirkland signature series washer will not spin fast enough anymore, to get all of the water out of the clothes. This just started happening. What does anyone think is the culprit? Where should I start the troubleshooting process?

Thank to all with any help! Stressed father of 4.

To check what is going on in your washer :

Remove the rear panel, and have a look on what is going on.
Check the drive belt : is it frayed?
Is there anything slowing down the drum?
Does anything look lose or broken?

Please be careful : do not touch anything while the washer is connected to the power.

If you can not find anything, remove the power - put the power cable out of the socket and on to the ground.

Remove the belt (it requires some force to remove the belt, but it is not too difficult).
Spin the (empty) drum a couple of times by hand, as fast as possible. Is the drum turning freely?
Spin the motor a couple of times : is the motor turning freely?

This procedure will allow you to research what is the problem in your machine.
Of course you can also come back to the board and discuss your findings!

Success !