Snowthrower engine pulley turns but traction belt does not
This problem is for a Craftsman 536.887990 snowblower. It seems to have gradually lost traction - occasionally it might still move but more often it does not. One thing I noticed is that when I engage the traction lever, I can see the engine pulley still turning but the traction belt stops turning (it might turn for a sub second, then stop again). It almost seems that the belt is slipping when the traction lever is pressed and the swing plate comes in contact with the friction wheel. The swing plate is in good shape and the friction wheel is also OK - there are some cracks in the rubber but I am not convinced if that is causing the loss of traction.
Additionally the "traction drive spring" that sits behind the traction drive idler pulley is broken. My thought is that while this should be replaced, its not the root cause.
Any suggestions on what the root cause is. I am going to try and replace the traction belt in any case, but if someone has a better suggestion, please let me know.