Lower Unit Shift Adjustment...Trouble

frustratedboater

Chief Petty Officer
Joined
Jul 10, 2007
Messages
413
I have rebuilt my lower unit and installed a new shift shaft, carrier seals and the like... I am not sure of the positioning of the shift cam in relation to the shift mechanism on the engine. I am installing a new side-mount shifter and new cables as well, so right now, the shift linkage is free on the motor... Right now, with everything hooked up/lower unit installed, no matter where I move the shift arm on the motor, my prop shaft seems to always be in forward gear and can't seem to find neutral.

I'd like to post pictures, but that usually poses challenges for me and not the easiest site to do so. How should I set to cam, where should I have the shift linkage slide (forward, middle, or back), and is there anything else I may have misaligned??
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Drop the lower unit off again. Rotate the shift shaft CW until it clicks into neutral. Set the shift mechanism in the slide to mid-travel. Install lower unit.

BTW, what engine?
 
Last edited:

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Pull the lower unit; rotate the shift shaft CCW with your fingers until it stops. This is the correct position for Fwd Gear. If you want to install the L/U in Fwd, move the shift arm slider forward.

You'll be able to turn the prop as you reinstall the lower unit, this will engage driveshaft into crank splines. Make sure your control is in Fwd too.

If you have trouble with this, pull lower unit and shift to Neutral. Using a pair of Vise Grips or equivalent, cushion shift shaft with a shop rag and turn the shaft CCW with the Vise Grips, the first detent you feel should be Neutral. Leave L/U in Neutral, move slide to middle and make sure control box is in Neutral as well.

You'll have to turn the flywheel as you reinstall L/U. Sometimes the shift shaft won't quite engage; since you have the shift arm loose, you can move it fwd/aft as needed. Generally Reverse is all the way back, Neutral in the middle, Fwd all the way to the front, but in practice you may find it's a bit biased one way or another.

Just a note, when the shift shaft is in the proper Fwd gear position, the reverse lockout rod in the mid-section will point to about halfway-up the ramp of the plastic shift cam, when the cam is properly installed on the shift shaft.

HTH.........ed
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
CCW is reverse. CW is forward. I prefer to let it click into neutral so it can't drift while manoeuvring the lower unit into place.
 

frustratedboater

Chief Petty Officer
Joined
Jul 10, 2007
Messages
413
The engine is a 1993 Merc. 115hp, inline 4-cyl... When I had the prop shaft out I had noticed that the shift cam (what the shift shaft slips into), just forward of the Forward Gear Bearing Race, had some travel marks on it and wanted to install it on the lowest of those marks. I will try to double check everything and make sure that it is lined up correctly. It is last and will take another peek at it tomorrow...
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
The shift cam must be installed with the letters and numbers on it, facing up. If you put it the other way round, the shifting will be backwards.
 

frustratedboater

Chief Petty Officer
Joined
Jul 10, 2007
Messages
413
Hey, I just wanted to follow up with this post. Yes, the numbers are up on the cam, as the manual states. I had pulled the prop shaft carrier back out again (gets easier each time with grease...) and sure enough, the cam rotated 180 degrees out! Thats' why the issues... Made the rotation, and re-installed the carrier. All operates fine and REALLY appreciate the help as always!
 
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