Kenmore washer will not spin?

My 8 year old Kenmore washer, model 110.20994992, will not spin. The parts list that came with it indicates it is a direct coupled motor drive. The motor runs when spin is selected, the pump emptys the tub. I also can hear the motor speed changing when I select different motor speeds. The motor stops when I lift the lid. I have the rear cover off and was planning to check the timer but I cannot determine how this unit mechanically engages for basket spin. There are no external solonoids or engagement bars so how does that part of the drive mechanism work. Any thoughts on what else to check after I look at the timer? What am I getting into if the internal mechanicals of the transmission drive are at fault?