Lower Unit Lube Question

[Bighand2]

This question is probably opposite for most questions about lower unit lube. I have a 1977 Johnson 70 HP outboard that is NOT electric shift. My question is - Can I use sae80w Type C in this outboard? I have a few tubes of this stuff from when I owned an electric shift outboard and thought that I could save a few bucks. Any help or advice would be greatly appreciated.

 

[Vic.S]

Re: Lower Unit Lube Question

The correct oil, as you probably realise, is a high viscosity outboard gear oil. ( around 80W90 EP)

I had not realised a type C oil for electric shifts is as high as 80W.

If you cannot use it I'd love to know why not!