The seal goes on the outside of the housing with the lip down or pushed in. Then insert the push rod or manual button. Screw the threaded piece or set screw into the end on the inside leaving 5-6 threads exposed. Use a blue loctite on the threads. Mine did not have a washer with it but I had one I put on it "lock washer" and then the lock nut. I threaded the set screw in until I could put the housing on and the gear was not being pushed out. I had a extra starter out already to set my travel.
Neil