My wiper motor came loose from the linkage so im trying to get it all working again. I took the wiper arms off thinking i needed to get in there, but i was wrong. Anways, i no longer have any reference point to get this all lined up. I can get the arms lined up again, thats no problem, my main problem is the small arm that slips over the motor stub and turns with the motor. Basically i cant seem to get it so it will stop at the bottom. its always somewhere else....

is this a trial and error (ive been trying for 2 hours) or is there a trick to it?