The 4 most common part(s) or condition(s) which cause the symptom Washer won't spin are listed below starting with the most likely. Check or test each item and watch any available videos.
RepairClinic Item # 1871380
If the washer won't spin, check the drive belt. If the belt is broken or if it isn't tight on the pulleys the washer won't spin properly.
RepairClinic Item # 2858
If the washer won't spin the drive block might be worn out or may have come loose. Underneath the agitator the drive block connects the inner tub (the one that spins around) to the transmission. If the drive block wears out the transmission shaft will still spin but the tub may not - or it may spin slowly. This also usually causes a lot of noise. The drive block is relatively easy to replace.
RepairClinic Item # 3319979
If the washer won't spin then the drive pulley might be worn out, seized, or damaged. Remove the drive pulley and inspect it carefully. If it is damaged or defective replace it.