1969 Mercury Lower unit 80hp install

[evangelistrr]

I am tring to install a lower unit on a 80 hp 1969 thunder bolt serial number 2561944. I have got a 85 hp thunderbolt that the lower unit appear to be good. went in to gear and out before I took it off the motor. Know when I try to install it on the 80hp it does not go all the way in "lower unit". The only differentance I can see it a little pin on top of the shaft my old one does not have this on there. Is this a different between them. Do all I need to do is much the pin. I was posting under rob619 earlier however I can not get in to that account it will not send me the password reset. Please any help at all..

 

[hotrod53]

Re: 1969 Mercury Lower unit 80hp install

I unfortunately don't have a good answer for you other than when I was looking for a replacement lower unit, I was told that I had to find a like unit that had the "preload pin" which is what you are referring to.