It seems to me that the bronze spacer(clutch) is worn too thin and needs to be replaced. This happens when a blade spins on the shaft because it was not properly tightened.
Gear Lubricant Question by Ken Potter
I have owned a Rockwell 315 for 30 years. I am replacing the armature and gear for the third time now. Maybe because I use masonry abrasive blades sometimes. What is the best lubricant to use in the gear case?
I cannot loosen the nut to change the blade on my Porter Cable 315 circular saw. I have changed blades on quite a few other circular saws, so I know the process. However in this case the hole shaft just spins even tho the blade is locked w/a piece of wood.
This is a fairly common problem with your model of saw. It has to do with the bronze washer and the sprung blade bolt wearing out. You will likely need to remove the blade bolt using an impact wrench. After the bolt is removed you will want to replace the bolt and the bronze washer. The blade bolt is part #846781 and the bronze washer is part #801669. Both are available from http://ereplacementparts.com.
Good luck with your repair!
-Mark
Response #2 Posted By John
You need the back wrench. A large flat wrench that fits the flat spots on the back washer. Your blade is spinning on the shaft and you can't hold the shaft still by jamming the blade. I have 2 315s and have used them since they came out.
