I have a Kenmore top load washer that hasn't been spinning, but will if you spin it by hand. Today it started making a loud knocking noise when entering spin cycle. Right now it won't spin at all, acts like it is locked up. It still will agitate and drain. I checked the coupler and its ok. I replaced clutch parts last year. So I am wondering if its the drive block or transmission. The drive block still has the notches in the side. So any ideas??