1979 omc sterndrive oil type

snowseifert

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It is a 3.0L 4 cylinder 140 hp model. I was wondering what kind of oil I should be running it.

Thank you.
 

Bondo

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Ayuh,.....
It is a 3.0L 4 cylinder 140 hp model. I was wondering what kind of oil I should be running it.

Thank you.
Ayuh,...... Welcome Aboard,....... Oil for the motor, or the drive,..??

What year is it,..??
 

Scott Danforth

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being a 1979, it would be white, it would be a hydro-mechanical shift stringer 400.

my guess this is a new to you purchase. please note that that drive was obsolete in 1980, replaced by the next obsolete drive that was from 1981-1985

if you havent done so yet, you may want to pull the drive apart, replace the vertical drive shaft, the raw water pump, and you may want to look at doing a ball-gear service. this alone will cost you about $1000 if you do the work yourself.

then you can put your marine gear oil back into the 3 separate gear boxes.
 

snowseifert

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Aug 30, 2020
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being a 1979, it would be white, it would be a hydro-mechanical shift stringer 400.

my guess this is a new to you purchase. please note that that drive was obsolete in 1980, replaced by the next obsolete drive that was from 1981-1985

if you havent done so yet, you may want to pull the drive apart, replace the vertical drive shaft, the raw water pump, and you may want to look at doing a ball-gear service. this alone will cost you about $1000 if you do the work yourself.

then you can put your marine gear oil back into the 3 separate gear boxes.
Thank you! Water pump was replaced last summer. I was looking for the engine oil type.
 

Bondo

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Thank you! Water pump was replaced last summer. I was looking for the engine oil type.
Ayuh,..... I run Rotella T 15W-40 in all the motors I have,.....

You can run pretty much anything on the shelf at wallyworld if you want,....
Clean, 'n fresh is more important,....
 

snowseifert

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Aug 30, 2020
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Ayuh,..... I run Rotella T 15W-40 in all the motors I have,.....

You can run pretty much anything on the shelf at wallyworld if you want,....
Clean, 'n fresh is more important,....
Okay thank you. I wasnt sure with it being a old engine. Do you run any zinc additive?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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the T15-W40 has zinc in it.

OEM manual for your 3.0 says SAE 30

just run the T15-W40
 
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