Merc 50 LU square shift shaft?

[verno]

Anyone know what models and or serial number groups had the square shift shaft? I have an NOS short shaft lower unit and having trouble finding a long driveshaft that fits it. I Tried two different driveshafts from my stash, one 70ish and one 1983 and neither will work. Other than the square top on the shift shaft, (I changed to the splined shift shaft). The lower unit is configured same as and will bolt up to early 70s to mid 80s but the driveshaft seems to be it's own design in the gearing business end. Another adventure in mercury learning experiences

 

[Faztbullet]

Re: Merc 50 LU square shift shaft?

It going to be a early 60ish model as it had straight gears instead of beveled and used a bolt to hold pinion gear on ,not a nut like the later models.