Gear oil

[waterboy84]

Im in the process of changing the lower units oil but im alittle stuck on what kind of oil/lub to put back in it. I have a 120hp force what kind of oil can i put in it when i drain the old thanks for the info

 

[flyingscott]

80W90 Marine grade lube

 

[waterboy84]

Thank you flyingscott. I appreciate the info

 

[jbcurt00]

Get a factory service manual, it'll have lots of helpful info in it, including LU oil specs. Having one will help you keep it running well.

 

[waterboy84]

Yes i been wanting to get a service manual but i dont even know the year of my motor. Is there any kind of way you could help me identify Certain things on or about the motor however i spoke to someone before but they wasnt much of a help. Only thing they told me was my motor was a 1990-1994 becuz i have the switchbox ignition. Is that good info on the year of my motor.

 

[jerryjerry05]

On the block under the ignition pack and coils is a foundry stamp.
​Or under the rear mid section is another stamp.

I use 80/90 gear oil from Wallyworld.
Been using it since 1988 no problems.

But I'm kind of anal about the drives. I check the oil every other trip and change it 2-3 times a year.

These lowers the bottom drain plug is an allen set screw.
It weeps water and no mater what I do trying to seal it, it LEAKS!!!

Finding a replacement unit 25in. ain't cheap or easy so I watch them very carefully.
I do have another just in case one of them takes a dump.