A common cause for this leak is the spring wearing a groove in the clutch shaft itself.If the engine is still together take a look at the clutch shaft just as it enters the seal,the spring usually sits at a angle and rubs a groove into the shaft.
The seal will have to be replaced and the shaft either repaired(brazing etc) or replaced,The bearing usually is ok but check,to prevent this from happening again just place a washer in between the spring and the seal,I think its about a 1/2" id washer ,My 02 came with a washer in place from the factory,not sure when they started to install them.