Hello, hopefully someone can help me find the issue on my parents washer. The washer agitates but won't spin, when the water empties out it makes like a drowning or whining sound. I have already changed the clutch, coupler and capacitor.

Today I took it apart and was about to change the drive block but seems it's in good condition as the drive basket tabs seem to be sitting fine on the drive block. Cleaned both baskets as I thought the build up of lint and grim caused the basket to not spin but after cleaning and putting back the basket and tighten the nut with the spanner wrench it seemed to not want to spin freely again. Put everything back and still wouldn't spin when trying it all put together. Any suggestions or advice would really be appreciated

Kenmore washer 110.81821110

Thank you so much for the info, will order the part and try it. Think that's my issue as I did a bit more research after your response and found a video of a guy explaining how to see if the transmission is working correctly and saw another one where the guy has the transmission open and explained my same issue. The transmission turns to the left and agitates and during the spin cycle it turns to the other side and if it doesn't, a gear inside the transmission either wore out or broke and doesn't allow the basket to turn. Thanks so much for the help, greatly appreciate the info. Will update when finished, thanks again