Help. Transmission oil? 1987 Merc 7.4L GM-454 V-8 ?

[WishGranted]

Hey guys.i don’t have the Merc owners manual and i had to replace the oil to my transmissions and Im getting conflicting recommendations for what to use. It’s 1987 - engine serial numbers B793144 and B793005.
I’m stuck at the dock and don’t want to do this twice by using the wrong one. Should I just use HD 30?

 

[Grub54891]

Transmission? Is it an IO or inboard? What color of fluI’d did you remove? What brand of transmission if an inboard?

 

[WishGranted]

Inboard. Oil hasn’t been changed for the 7 years I’ve owned the boat. And the oil wasn’t black but a rich brown. (And not red).
Not sure if the transmission. But connects to a Walter V-drive if that’s a clue.

 

[WishGranted]

I don’t know the transmission, but it’s pushing a Carver 38’ Santego 3867.

 

[Scott Danforth]

Non detergent SAE 30

 

[Grub54891]

Non detergent SAE 30

Yes. There should be a tag on top of the v-drive stating the brand, possibly velvet drive or the like.

 

[Scott Danforth]

back in 1987, every fluid on your boat would most likely be SAE 30. it will be in the steering system, the trim tabs, the motors, and the drives.