1962 75hp Johnson Lower Unit reinstall

[rmulek]

This is my first post to the forum. My first boat/motor I've owned but I've been on the lake and boating for many years. Luckily friends and relatives have always owned boats. I was given a 1965 Crownline boat with this 1962 Johnson. It's been in a garage for 16 years and never used in that time. It would not start but after I've rebuilt the carb, fuel pump, starter repair, reed valve gaskets and cleaning, new gaskets for the heads and exhaust cover plus timing adjustments I got it running.

I'm down to replacing the water pump/impeller and have that completed. My problem currently is reinstalling the lower unit. The drive shaft spline need to line up with the power head and that is where I am running into problems. I have read that if you turn the prop at the same time you raise the lower unit into the power head it will turn the drive shaft to help align the splines. But on this motor turning the prop does not turn the driveshaft. I'm not sure if it's because its the Electromatic shift or what. Also the new water pump kit came with new O-rings for the drive shaft. It goes on just after the drive shaft splines but it is slightly bigger that the original O-ring. ​The Johnson dealer said the bigger O-ring was just an improvement from the old one. But I'm wondering if the bigger O-ring is what is causing part of the problem. That and getting the splines to line up.


Any tips for getting the lower unit reinstalled on this vintage motor.
Thanks for any help

 

[joereeves]

I've often wonder why they changed the original part number. I just checked my remaining stock whereas I have those O Rings (both part numbers) in one bag... yes, the later number is ever so slightly larger. No, that would not interfere with the installation of the lower unit as the O Ring sits below the splines.

Make sure those splines are well greased.

The solution to your problem..... simply have someone slowly turn the flywheel by hand. On that model, there are four (4) splines so somewhere within a 90 degree turn, those splines will line up.

 

[rmulek]

I've often wonder why they changed the original part number. I just checked my remaining stock whereas I have those O Rings (both part numbers) in one bag... yes, the later number is ever so slightly larger. No, that would not interfere with the installation of the lower unit as the O Ring sits below the splines.

Make sure those splines are well greased.

The solution to your problem..... simply have someone slowly turn the flywheel by hand. On that model, there are four (4) splines so somewhere within a 90 degree turn, those splines will line up.

Thanks for that quick reply. That helps, better understanding of where the O Ring sits. Ok, just turning the fly wheel makes sense. We'll give that a try, sounds like it should just slide in after that. The pump kit included a packet of molly lube to coat the splines. Again thanks for the fast response.

 

[joereeves]

Thanks for that quick reply. That helps, better understanding of where the O Ring sits. Ok, just turning the fly wheel makes sense. We'll give that a try, sounds like it should just slide in after that. The pump kit included a packet of molly lube to coat the splines. Again thanks for the fast response.

I strongly suggest that you remove all the spark plugs first to avoid any accidental starts that'll rip your hands off!