Volvo Penta 4cyl 3.0GL 230B (1994)

[Crej#8]

I am wondering if someone has an opinion on what type of oil I should use? I am changing the oil myself this time around and have no idea what the previous mechanic used for engine oil. I also had a Bellow issue and laid the lower unit down so now some of my oil/gear oil leaked out so I’m wondering what to put in the lower unit as well. An old timer told me to use just straight up SAE 20 (hard to find) and then I see other information saying I can use 25W-40 and the list goes on. I have no owners manual available and I can’t find anything online that gives me a definitive answer.
Thank you for any insight!

 

[bondo]

Ayuh,...... I run 15W-40 diesel engine oil in all my motors,.....
The drive should use 75W-90 syn. gear oil,....

 

[Crej#8]

Ayuh,...... I run 15W-40 diesel engine oil in all my motors,.....
The drive should use 75W-90 syn. gear oil,....

Thank you sir! That’s ok even if I don’t have a diesel? I was reading another thread where a guy had a 1993 with same question. His manual said to use 20W-50, and he could also use the same for the lower unit. As per other specs I found online it said that the same oil in engine OR GL-5 which I believe is the 75W-90 you mention would be ok too. The oil that leaked out looked “greenish” so i’m guessing they had gear oil in that last time around? Asking because I heard you shouldn’t switch back-and-forth. Thank you once again for any insight. I’ll wait to see what you say and then I’m just gonna make a decision. I’m not gonna stress about this too much. I see other people who get really worried about what oil to use….