NOW to make sure its EXACTLY in the middle to eliminate any wobbling ! BUT the wiper motor don't turn very fast so IF there is any wobbling , keep the belt sloppy and add a spring loaded idler pully to keep the belt adjusted. I made my own and had it on my dredge to ensure the best belt surface contact without putting a lot of tension on the belt that would cause early belt wear. I sold that dredge to Bill_Saf and he sent me a picture of what I made and its posted here (somewhere) but Ill try to repost it ! Also a little tip for you now that the nut is welded on...............use some nylon fishing line to insert into the nut before you screw it onto to the motor shaft. This will act just like a nylock nut and WONT back off!