Mercury Lower Unit installation

jhall555

Cadet
Joined
Mar 4, 2010
Messages
19
1973 Mercury 40hp 402 SN: 3476258

Before I took this apart, everything worked correctly.

I am in the middle of installing an extension kit, everything has gone smoothly except for the lower unit gear (FWD, REV, NEUT), I took out the gear assembly on the prop shaft to inspect them. Everything looked great.

After I installed the gear assembly back into the lower unit, and I try and spin the prop, it does not spin one way, and the other way it just clicks and never engages. The drive shaft also does not spin when I spin the prop. The shift shaft spins (not 360 degrees, it stops 3/4 and I can spin it the other way 3/4) and feels like it is not engaged. This is with the lower unit detached from the power head.

I know that there is a "pin" (sorry I am not too familiar with outboards) at the end of the prop shaft that has a coned shape on the end of it and is spring loaded, which should push up against the lower part (shift cam?) of the shift shaft and that is what engages FWD REV NEUT. Do I need to physically turn that shift shaft with the lower unit detached to engage?

Again, I apologize if this is confusing, and can post pics if needed.



Here is a diagram of what I am working with:

http://www.boats.net/parts/search/M...OUSING ASSEMBLY, COMPLETE (PAGE 2)/parts.html

Thank you so much in advance for any tips/advice
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Mercury Lower Unit installation

You need to drop the unit down, then shift it into rev. put the engine in rev and reinstall the unit. The shift shaft is not aligned
 

jhall555

Cadet
Joined
Mar 4, 2010
Messages
19
Re: Mercury Lower Unit installation

You need to drop the unit down, then shift it into rev. put the engine in rev and reinstall the unit. The shift shaft is not aligned

That makes sense! Thank you so much!
 

jhall555

Cadet
Joined
Mar 4, 2010
Messages
19
Re: Mercury Lower Unit installation

Stupid question and simply just wondering: Does the motor and lower unit have to be in REV to reinstall or could they be in Neutral or FWD ?

What is the best way to get the lower unit in REV? Turning it one way or another, how many "notches" should I feel before hitting REV?


Thank you again, and I think I should be good to go after this.
 
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