Lower Unit

Zimmergl

Recruit
Joined
Jul 27, 2015
Messages
2
Have a 1986 Nissan 12hp and I've removed 4 nuts from studed lower unit and pin from shift linkage.lower unit will not separate am I missing something.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Welcome aboard.

Started a new thread for you. Please read the Help Tip on top of the page about old threads. Thanks.
 

Sea-Alice

Cadet
Joined
May 7, 2009
Messages
10
No Title

I've finally conquered the same problem on a 2001 Tohatsu 18hp four stroke used around saltwater. Here's what I did. Removed the powerhead to ensure the shaft wasn't rusted to the engine - this removed weight from the unit so I could manipulate it easier; probably not necessary on two strokes. (I am curious whether mechanics have ever found rusted shafts unless engines were submerged.) Struck the LU judiciously with a rubber mallet and pieces of wood to no avail - had no gap at all. I drilled small holes on both sides where the flanges came together (see picture) and applied PB Blaster and/or Sea Foam Deep Creep in these holes and around the SS studs. I did this and rotated daily with the unit laying flat. Finally had to heat it with a propane torch and finally got the gap widened enough to begin wedging the two pieces apart. Note the corrosion on the bolts (see picture); the flanges were painted sufficiently well as to not corrode together. Hope this helps - just minimize any damage and take your time.
 

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Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
If you have already a stuck drive shaft inside crank shaft you have a problem, removing powerhead won't ease the situation as the powerhead will turn sideways but not disengage upwards. That's why is a must grease upper drive shaft splines from time to time to avoid those unwanted conditions, check if possible to achieve a small opening between lower middle and lower leg to insert plastic wedges and work from there pulling lower leg offf. Good luck.

Happy Boating
 
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