I have a John Deere Model 660E tiller Serial #Q09226 on a 1050. The bearing behind the lower sprocket of the chain drive has locked up. On the outer shaft is a 4 slotted nut that is exactly like the hub nut on an old Dana 60 4X4 truck front end. In fact, I have the hub socket that fits this but still can't get it to budge. Can anyone else offer suggestions as to how to get this loose? Also, will I have to use a wheel puller to remove the sprocket behind it or should this just slide off?