1937 Ford windshield wiper question.
 

If someone has a known 1937 Trico wiper motor could they look at it and tell me what I need to know. The original standard black arm from my coupe and a couple 37 Bob Drake ones I have ,they have a serrated hole that attaches to the motor shaft. My question is the motor shaft what is it supposed to look like ? Mine is brass ,threaded on the end for the nut and has a taper not a matching serrated diameter .Is this correct? I don't have the original wiper motor from my car,it was replaced. The Bob Drake arm no matter how tight I draw it down with the nut comes loose after a few minutes. Got the motor from Ficken years ago as he had issues fixing my original. Scarey day yesterday in a downpour. Thanks

Re: 1937 Ford windshield wiper question.
 

try using some plumbers teflon tape

Re: 1937 Ford windshield wiper question.
 

Well I got an email answer to my question that explains it all. Another example of todays manufacturing that I will never get used to,"Form over Function". The email was from a well known Trico wiper rebuilder and stated that my problem was probably due that the repro arm was made off a well worn sample,the internal spline will not fit to shaft correctly and come loose. Form over function seems to be the norm ,it only has to look like a wiper arm but will not work as such,sorta like Ford script fan belts that don't fit but look good. Guess my answer is to stay out of the rain.