API GL-5 in DF300AP lower unit?

[ChrigelKarrer]

Manual require LU oil for hypoid gears, today this is virtually impossible to find (at least not written on the bottle and/or not in Costa Rica), BUT
as far i was reading API GL5 has the same properties and should be fine for hypoid gears.
Do i miss something?
Chris

[Murray]

I've been using automotive API GL5 gear oil in a 1995 40hp Mercury for 10 years and haven't had any LU issues. My Suziki dealer sells Quicksilver gear lube, claims it's a better product than Suzuki's product. Reading the bottle "improved emulsifiers to help protect gears should water enter the gear housing". I'm guessing standard gear oil (automotive) will be lacking the additives for marine applications. Personally I'd be looking for the proper oil for a 300hp, those gears are spinning fast, not to mention the "extreme pressures". For my DF90A I'm using marine grade ($19/L), the beater Mercury gets automotive ($6/L). It will be interesting to see what the real experts on this forum think.

[Harper]

I use Amsoil Synthetic Marine Gear Lube 75W-90. It's rated API GL-4, GL-5. Meets specifications and requirements of all marine outboard manufacturers, including Suzuki. Most all your gear lubes are for hypoid gears.