1979 OMC Gear Lube

Buzzsaw420

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Good afternoon, I have a 1979 120 hp OMC with the 400 hydro- mechanical outdrive. I have looked thru other threads and can’t find that combo to find out what gear lube to use. Any suggestions? Thanks in advance, Buzz. Still trying to get a service Manual.
 

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Scott Danforth

Grumpy old guy who plays with boats
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or yamaha or synthetic or ....... you get the picture.

remember, you have 3 gear boxes. the intermediate attached to the motor, the upper and the lower.

i would split the case, throw in a new raw water pump kit with a housing and inspect the vertical driveshaft (the splines wear and strip out.)
 

Buzzsaw420

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Ok it’s going to be a bit before I get to the vertical drive shaft but now that you explained that I have written that down on what started as a memo and looking like an encyclopedia. Does the gear oil need to be specific(75w140 example) or just high performance, etc. Thanks again.
 

Scott Danforth

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Ok it’s going to be a bit before I get to the vertical drive shaft but now that you explained that I have written that down on what started as a memo and looking like an encyclopedia. Does the gear oil need to be specific(75w140 example) or just high performance, etc. Thanks again.
75w90 marine
 

racerone

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You might not be aware that these OMC sterndrives are not high on the hit parade.------Be prepared to do the maintenance or replace drive / replace boat.
 

Buzzsaw420

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You might not be aware that these OMC sterndrives are not high on the hit parade.------Be prepared to do the maintenance or replace drive / replace boat.
Oh ya I’m aware, I feel like I stole someone’s kid when I ask an OMC question and the next thing you hear is junk it. I got the whole kit and kaboodle for $500 because the guy couldn’t store it anymore. There’s lots to do but me and my son are determined to fish out of her this summer. The guy told me he just did the wires,plugs etc and lower end so I’m going from there. Cheers, Buzz.
 

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racerone

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Well----60E ---appears to be from the Bracebridge / Muskoka area.------I see ( in the pictures ) some issues with stringers / wood under the floor in your future.
 

Buzzsaw420

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Well----60E ---appears to be from the Bracebridge / Muskoka area.------I see ( in the pictures ) some issues with stringers / wood under the floor in your future.
Interesting Muskoka is 3 hours north of me so she’s been around. You are very right about the floor also.
 

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racerone

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Well-----That mess is no surprise at all.----Looks like some repairs had been done already on it.-----Support the hull in a frame.----Cut that junk out and put some composite material in there.-----Most folks would say that there are better / easier projects around.-----Your location.
 

Scott Danforth

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Yep that was under 2 layers of plywood and one really scummy carpet! Mice liked it.
your boat is the victim of a "deck over" the boating equivalent of buying a car with 5 gallons of bondo over the sunday comics to fill in giant rust holes.

basically, you need to pull the motor and drive and replace the transom, strings and deck.
 

bruceb58

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Hate to tell you this but I would just accept your $500 loss and find something different.
 

racerone

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Boats like that must be , and are often scrapped.----Or they must be repaired properly.-----If a hull like that fails in Canada ( ice cold water ) with the boat sinking the event might be in the newspaper.-----It sadly won't be on the sports pages.-----
 

Buzzsaw420

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Boats like that must be , and are often scrapped.----Or they must be repaired properly.-----If a hull like that fails in Canada ( ice cold water ) with the boat sinking the event might be in the newspaper.-----It sadly won't be on the sports pages.-----
Hopefully the Restoration of the Century section.
 

Scott Danforth

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Hopefully the Restoration of the Century section.
after $6k and 1-2 years maybe.

just in the raw water pump, vertical driveshaft, tilt motor and ball gear kits (normal maintenance) your bouncing off $1k just dont damage the lower shift cable. that is getting close to another $1k

the hull is another $3-4k

interior is another $2-3k

so all told, your between $7-9k to restore it to make it safe.
 
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