Do I have to use a marine type gear lube or is automotive 80-90 ok for my lower unit lube?
Howdy,
It's fairly important that you reveal exactly what you have! Some diifferent drives use different oils. (Some Volvo drives actually use regl'r motor oil!!) Most of us will need a leetle bit more info than "Verical Unit"
Welcome aboard. You can use any lube you want, but marine gear lube is preferred over auto. Marine is supposed to work better if water happens to intrude into the lower unit.
That, however is the claim of the manufacturers of the "Marine" lubes of course......
Since there is no NMMA specification for "Marine" gear lubricant, it's true, You can use any correct wt gear lubricant. And also true, if you have an electric shift OMC drive, there is a rather specific lubricant recommended for it BY OMC......... Sierra sells it as does Evinrude and others............
If you're talking about a Cobra, you can use any hypoid gear lubricant of the correct SAE weight rating.
Most of us like the synthetics like: Mercury HP, Mobil1, Volvo Synthetic, Am$oil, and a few others. (Mercury and Am$oil actually
claim adequate lubrication with water intrusion)
AM$OIL Synthetic Marine Gear Lube is water resistant. It maintains extreme-pressure protection even when contaminated with as much as 10% water. It promotes longer seal life to help prevent water contaimantion. AMSOIL Synthetic Marine Gear Lube is designed to prevent rust and is compatible with aluminum, copper and brass alloys.
yada yada yada...........and they claim to do an actual standard test with 10% water,
FALEX Extreme-Pressure Load
Test B (LbF) (ASTM D3233B)
(Understand, there IS no special "marine" test for lubrication quality with 10% water) I suspect that ALL hypoid gear lubricants meet the test parameters with up to 10% water........which might be why the NMMA didn't bother to come up with a "marine" spec for gear lubricants......
If you're changing the oil in a Cobra, use whatever you want and you can get it from Autozone O'reillys, West Marine or your favorite marine guy.
If you're changing the oil in a DOG-clutch Cobra, BE SURE TO FILL IT CORRECTLY ACCORDING TO THE OMC SERVICE MANUAL! DO NOT FILL IT FROM THE BOTTOM (drain port)
Cheers,
Rick
