1973 MERCURY 50 HP lower unit re-install

[old folk]

How do I reinstall the lower unit and get my shifting lever to operate properly ? I can get the lower unit back in place but the shift lever will not go into neutral or reverse, have done installation twice, trying with controls in fwd gear & neutral as well, same result, shifter always locks up.

 

[merc850]

Well I'm assuming this is a 4 or 6 cyl. motor if so:This is how I do it in about 60 sec.: Turn the LU shift shaft by hand counter-clockwise until it
stops, then with Vise Grips tight on the bottom of the shaft turn it a
few more degrees CCW until it clicks into a stop, this
should be neutral - check by turning propshaft --
prop should spin freely.
Put control in N and go ahead and attach LU to driveshaft housing some turning of the flywheel will help the DS splines align.
Do not shift into reverse unless you turn the prop at the same time.

 

[Texasmark]

Drop the LU whereby the shifter linkage is unmated at the splined shift shaft at the front top of the LU. Move the remote control through FNR to ensure that it's movable on it's own and place in the N position with a slight rocking motion to ensure that you are in the center of N.

With a pair of vise grips (my favorite tool but pliers will work) grasp the shift shaft stub on top of the LU, mentioned above, and attempt to twist the shaft one direction or the other with a mild to moderate twisting motion. It should move one way, the other, or both ways. Turn it until it's at a limit and you can feel a little detent which, upon slight rocking of the shaft feels like a pointed object in a conical object seeking the bottom.......which is just what you have with your shifter 3 position cam and the cam follower on the front of the prop shaft.

Rotate it back and forth a couple of times to get the feel of it and set it in the center position....N. Recouple your LU and things should work for you.

Mark

 

[old folk]

Thanks for the help on LU install & shift problems, will give it a go Mondy

 

[Stacraft1768]

I am in the same spot, and have tried this a million times by now, when I get the shift shaft in the position where the prop spins freely "neutral" , A the upper and lower cam are misaligned B when I do get it reassembled the controls are locked up in the neutral position. merc850 said not to shift into reverse w/o spinning the prop. What issue would be caused by shifting into reverse and not spinning the prop. Simultaneously?
I have a 1965 Mercury 500 50hp
Any help would be great I am yet to get this boat on the water