I have a Whirlpool Gold washing machine, model number LSB6500PW4. Recently, the basket either doesn't spin at all or spins slowly during the spin cycle. When it doesn't spin at all I can manually turn the basket a couple times and then start it again and it works but still turns slowly. I tested the draining of the water to make sure there is no blockage. The tub drains completely well within the 180 seconds before the tub starts to spin. Sounds to me like the clutch is going. Do you concur? If so, is that a part I should try to replace myself or hire out? Thanks in advance.

Is the Gold series belt drive? I can't remember. I would look and see. Could be as simple as a wore out belt. Not a difficult job. If it is the clutch and you are handy you could change it yourself. Not a real difficult job. Just pay cose attention where eveything goes. Maybe take a photo prior to disassembly for reference. Good Luck

There is a belt that appears to turn the water pump but other than that it looks like direct drive.

Then I would inspect the coupling between the motor and trans.