Can't get my lower unit on

[chris16371]

1973 Merc 500. Started up motor today to check a couple things and the impeller stopped pumping water. I already had one on hand and replaced it but now can't get the lower unit back on. Water tube is positioned correctly and so is shift shaft. The shift shaft coupler was kinda looking bad and I had an extra so I swapped it out but everything is lined up correctly in forward gear.

 

[GA_Boater]

Given the distance, it looks like the driveshaft isn't going into the crank shaft splines. Turn the flywheel a bit or if you have the motor in gear, rotate the prop slightly.

 

[chris16371]

I turned the fly wheel but had to do it with motor in gear bc of shift shaft being locked in forward on lower unit. I appreciate your help! Worked perfectly!

 

[chris16371]

Ik you said to turn prop if motor was in gear and I did but the driveshaft didn't turn at all when rotating the prop so that's why I had to turn flywheel with it on forward gear. Was the driveshaft suppose to turn as I turned the prop? It just made a clicking noise. Now that it's all back together everything seems to be working the way it should.

 

[GA_Boater]

Clicking sound means you should turn the other way. :smile: Turning the other way would turn the driveshaft.

The click is from the dog-clutch that stops the prop from driving the motor backwards if it stalls in forward gear.

Time to go boating!

 

[mav6759]

On the front of the lower unit, there is a gear that has to be lined up with the splines as well, I forgot what this gear is called...but you have to make sure that gear is line up inorder for the lower unit to go in...

 

[Mercurylips]

I turned the fly wheel but had to do it with motor in gear bc of shift shaft being locked in forward on lower unit. I appreciate your help! Worked perfectly!

Chris- Next time you need to turn your main drive shaft to get your lower up, loosen the spark plugs and the shaft will turn much easier. I just loosen the top 3 on my 50.

 

[chris16371]

I didn't known I could turn prop the other way, didn't want to force it and break something lol but now Ik for next time that it will just turn the drive shaft.

mav6759 I think your referring to the shift shaft coupler, I made sure they were both lined up in forward gear. That coupler doesn't seem to be of high quality material and would be very easy to ruin so that was the first thing I checked. I appreciate everyone's replies!!