I had to study HOW it works and how things react with others before I could understand where the cogs are supposed to go. If you hold the arm too high, the cover won't go on, hold it too low, and it won't engage the cogs...therefore, I started too high, and by trial and error (kept lowering the arm for each successive attempt) found where the arm position needed to be in for the reverse cogs to "find their home". It IS a pain in the a$$, but once you get it it's not that bad. A good test: when you get the cover on and you wanna "test" to see if the lever made it in the right position, moving the arm toward the engagement position for the reverse will pull the cover INTO the motor, if the cover wants to push OUT, then you don't have the cogs behind the gear slot you have the cogs in front of the gear.....I think that helped me....