In this picture you can see the effect, and penetration, of the PB Blaster penetrating oil. The coupling has broken free and is beginning to come off through the tightening of the bolts.


If you have trouble getting the shaft and coupling apart you can heat the center of the coupling very slightly with a heat gun (make sure you have an extinguisher on hand just in case) heating it in the CENTER will draw the PB Blaster into the coupling due to capillary heat draw.