I have a Poulan Pro model PR55R621CA. Rear drive shaft turns fine, but wheel drive pinions are not "gripping" the shaft. I don't have any experience with this design. What makes the shaft "connect" to the pinion? I need some help!
I was going to check my Poulan Pro riding mower to help with your problem, but then I realized your mower is a walk behind? Sorry. An expert on the site should come along soon.