3 Piece Drive Shaft Coupler Bolt Procon coupler bolt-on 56C for Series 2, 3, 4 5. There are two wheels and a spider in this set. It?s dirt-resistant and is also reliable against dampness and grease. Make sure the motor is unplugged and can't switch on while you're installing the drive shaft coupler. The motor should be connected on half of the connection of the motor shaft and the set screw should be made very tight. You shouldn't have to force the coupling on the motor shaft and pump. It's important to check that the shaft doesn't stick out past the elastomer component as well. An established and trustworthy company that you can rely on produced this item.