Horrible grinding sound when spin cycle ends.

After washing a blanket my washer made this awful grinding noise as the spin cycle stopped. Thinking it was just strain from a heavy sopping wet blanket I gave it a rest and tried a small load of clothing the next day. To be clear the washer still spins, agitates and carries on as normal all the way up to the spin cycle. Its not spinning enough to wringe out the clothes they're still soaked but it does spin. When the spin cycle ends it comes to a slow halt and makes this banging and grinding sound. What part could it be and what should I look for when I take this thing apart?