Lower Unit question

fancy1

Seaman Apprentice
Joined
Aug 14, 2011
Messages
31
Our 1977 Mercury hasn't been running right it sounded like it was getting air from somewhere so we replaced all the fuel lines fuel tank and everything hoping this will work, well while we were doing all this we decided to take the LU off to see if we could get the locking mechinism to lock when in Reverse now we can't get the LU back on right, we had forward, N and Reverse before, well now we can only get Neutral and Reverse. We took it back off several times and put it back on after turning the shift shaft but we still can not get Forward at all any clue as to what we can do.? We followed the manual.
 

Alannuts

Recruit
Joined
Jul 8, 2012
Messages
4
Re: Lower Unit question

Our 1977 Mercury hasn't been running right it sounded like it was getting air from somewhere so we replaced all the fuel lines fuel tank and everything hoping this will work, well while we were doing all this we decided to take the LU off to see if we could get the locking mechinism to lock when in Reverse now we can't get the LU back on right, we had forward, N and Reverse before, well now we can only get Neutral and Reverse. We took it back off several times and put it back on after turning the shift shaft but we still can not get Forward at all any clue as to what we can do.? We followed the manual.

The prescribed method for putting the LU back in is as follows:

1. Place shifter in forward gear position
2. Turn the shifter splines on the LU in a counterclockwise direction until you feel the indent for the Neutral position.
3. After finding neutral, turn the prop by hand in a counterclockwise direction only while you turn the shifter splines counterclockwise again until it clicks into forward gear.
4. Reinstall the LU being careful to align all the shifter splines with the upper unit as you do this. If you need to turn the prop to align the motor splines, do this in a counterclockwise direction.

Good luck! This can be a pain to get it all aligned and a helper is good to have!

Alan
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,803
Re: Lower Unit question

Alan's instruction are not correct, but they are pretty close. Skip Alan's step #3 completely and substitute this: Set the Control to neutral and reinstall the gearcase. Turn the flywheel by hand to align the driveshaft splines. Grease all splines before reassembly.

Remember the reverse lock should lock the motor down in neutral and reverse, but not in forward.
 
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