Lower Unit

62cruiserinc

Petty Officer 1st Class
Joined
Oct 30, 2009
Messages
295
Right now, my 1981 Sea Ray is sitting on blocks at the marina about 10 miles from home. I need to replace the impeller and gear lube.

Is there any reason I can't just unbolt the lower drive unit from the upper and take it home to my workshop to replace the impeller, seals, etc. and then take it back and bolt it on? I would cover the exposed upper unit with a plastic bag taped over it while the lower was at home. I have a lot of tools at home and it would be more convenient, especially if there were any surprises during the impeller replacement.

Also, can the pressure test on the lower drive unit be performed while it is off the upper unit? I have seen videos where they do that. Isn't there an oil passage between the upper and lower unit that has an o-ring seal? Wouldn't the pressure leak out through that passage if it was removed from the upper?

Thanks
Steve
 

alldodge

Moderator
Staff member
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Mar 8, 2009
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42,535
Don't see any issue with your proposal with the impeller change.
 

Rick Stephens

Admiral
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Aug 13, 2013
Messages
6,118
To pressure test the lower you just have to plug the oil passage.

Personally, I don't like installing lowers to hanging uppers, easy way to damage seals and it's a bear to line up everything while you lift. Super fast and easy, 5 minute job, to pull the whole drive and do the reassembly by dropping the upper down onto the lower. Far easier.

Rick
 

bspeth

Senior Chief Petty Officer
Joined
Aug 30, 2013
Messages
758
Take the whole thing home and build a nice stand for it,you really should pull it every year. With a little practice it really becomes routine.
 

62cruiserinc

Petty Officer 1st Class
Joined
Oct 30, 2009
Messages
295
It does sound like a good idea to take the whole outdrive off and take it home. Remove six nuts, disconnect the tilt rams and pull it off from what I see on videos. Also, I can check some of the other parts to see how they are.

A stand is a good idea. I have a woodshop so making a stand will be easy.

If I pressure test and fill the outdrive at home, will there be any issues with laying down the outdrive on its side in my car while taking it to the marina?

Thanks for the suggestions.

Steve
 

Rick Stephens

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Aug 13, 2013
Messages
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If I pressure test and fill the outdrive at home, will there be any issues with laying down the outdrive on its side in my car while taking it to the marina?


Steve

None. As long as the seals are halfway decent, it won't even drip. Lots and lots of boaters do that. And over the winter, not having an outdrive on a stored boat means no one can borrow it.

Even with the boat stored in my shop I leave my outdrive on a roll around stand for the winter. I service it when I winterize and then leave it on the stand until spring. When I reinstall I check everything over, wipe a thin layer of 2-4-c grease on any bare metal, like input shaft and bellhousing studs. Slide the alignment bar in for a quick double check and finish up checking everything else. Way I built my stand the drive won't slide in with the prop on it. This is good and bad, I'd like it assembled with prop, but this also means I always have the prop off for the winter and can check for fishing line wrapped on the shaft and I can grease the splines - necessary maintenance.
 

62cruiserinc

Petty Officer 1st Class
Joined
Oct 30, 2009
Messages
295
Well, I pulled the whole drive off yesterday evening. It only took about 10 minutes to remove, but next time it probably would take half of that time.

The boat is a 1981, but the previous owner replaced the drive with an SEI about 5 years ago, so everything came apart pretty easily.

What do you guys use to clean the gasket surfaces with? When I work on car engines I use a scotchbrite pad to clean off the metal surface. Also, do you use any sort of gasket sealer, or just use the gaskets dry?

Thanks
Steve
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
The gasket goes on dry. Use a scraper, or scotchbright as long as you don't remove aluminum. I also use acetone to make it squeaky clean and dry before reassembly.
 
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