After consulting with the Amsoil rep, went with 75-90 Severe Gear, he reccomended it over the Marine, said it is a much better oil for this application. Said not to use the heavy stuff unless running real high HP, has better shock protection but doesnt "wash" the gears down as well.

Cool...thanks for sharing. Sounds like Gadgets is on to something with the thicker stuff holding on to the particles.

I ordered the 75w110 today as hot as these drives run I'm going to give it a shot. I'm trying to keep this bravo alive for one more season.

Missed your post. I have never run it in drives. I have always used Merc lube with frequent changes and never had any issues.
I have run the Redline in hot rod car rear ends with great success. Launching of a starting line at 3500rpms with 12" slicks and shifts at 6000rpms and it worked well.

I think Mr G has a very good point about it being sticky and not letting the metal fall off the gears.

Talk to a friend of mine today about a guy running synthetic in his drive don't know the brand or weight, but it foamed and built so much pressure it blew all his drive lube into the bilge and when he removed his plug it shot out and they couldn't find it. This concerns me now.

Does anyone think the 75W110 will be too heavy and cause foaming issues? I've run the Amsoil 75w90 Marine lube, but never just plain gear lube...Don't know if there's a difference?

I just ran my boat today for the first time with the new 75w-110 in my bravo X's 30p. Ran flawlessly, and for the people who think you're going to lose speed do to being a touch heavier, my boat ran the same! I would not be concerned one bit. The most probable reason for the foaming would be water. Did he add anything to the product? That might cause an issue too.

I don't know the details all I know is it was synthetic gear lube. I'm glad to hear yours ran flawlessly cause that what I have to run in mine...I hope you'll come back and post after running it for a few hours when you drain it as I'm lucky if I put 25-30hrs on a year, so unless I have issues I won't know for a complete season how well or not it worked.

Royal Purple is synthetic.. been running it for 15yrs or so.
If your buddy had water in the lube, it would have shown up on the drain.. At some point it will settle out.
RP has a very quick seperation period. Water falls out very quickly, so I have been told by the reps.
How did your buddy fill the drives?? That may or may not be an issue.

Wasn't my buddy he was just at a run and had this happen. I've run Amsoil in my drives for 4yrs and never had a issue as well was just a concern and figured I'd post to see if anyone else had experienced that problem as well.

Keith I do have one, but the upper case needs to be drilled for fittings. Not something everyone wants to do on their own.