What does Merc recommend for a GL (Gear Lube) rating on the Bravo drives? GL-4 or GL-5. Anyone have any thoughts on this recommendation? Does anyone think a GL-4 is inadequate? I need to know.

Thanks,

I use AMSOIL GL4 exclusively in my Bravos. I run twin 565 hp. I change at approximately 25 hr intervals. I believe it superior to Merc High Perf lube. I've used AMSOIL for years.

Merc doesn't specify anything but their own product for the outdrive. Personally, I use a Pennzoil 100% synthetic (GL-5) that works great. FYI, Volvo recommends GL-5.

I'am running the Amsoil 75-90 , it has a gl-2 through a gl-5 rateing

Interesting how many use Amsoil. I have become a distributor for Amsoil mainly since a friend of mine purchased a couple of Teague Platinum drives and they highly recommend Amsoil. I even called them to ask which one they used and it was the same one that Amsoil recommends for Outboard lower units and sterndrive lowers which is the 80W-90 AGT/ALU which is only rated GL-4.

Amsoil offers about 6 different gear oils. Only the AGT/ALU is recommended for Sterndrive use. I will contact Amsoil and find out why the others would not be recommended. Here is the list of what they carry.

AGR 75W-90 (GL-2 thru GL-5)
AGL 80W-90 (GL2 thru GL-5)
AGT/ALU 80W-90 (GL-4) Recommended
AGO 85W-140 (GL-2 thru GL-5)

Series 2000
TGR 75W-90 (GL-2 thru GL-5)
TGO 75W-140 (GL-5)

The technical properties of these lubes do not differ significantly although the four ball wear properties of the recommended lube is better than the others.

Thanks for the input. I will continue my research. I have to have the answers when people ask me why.

That's interesting that Teague specified Amsoil. I've always known them to endorse Redline products.

They claim that the Amsoil gear lube resists foaming better than anything else on the market. I spoke with them directly.

Is anyone using the Mobil 1 GL5 Synthetic gear lube in their Bravo?

RED LINE SHOCK PROOF ,JUST LOOK AND READ ON THEIR WEB SITE IT WORKS GREAT AND SO DOES MOBILE AND AMSOIL ,MY OPOION RED LINE SHOCK PROOF IS BETTER IN GEAR BOXES BECAUSE IT STAYS ON GEARS ,MY 2 CENTS WORTH

Bobby, which weight of shockproof do you recommend? Seems like the Heavy weight might be too heavy.