Gear Lube
 

What is the best possible gear lube for an Alpha 1 Gen 2. I know the Bravo's dont like it too slick due to clutch cone but the Alpha does not have that. Have 5500 lb 24 ft boat with a newer 357 magnum Plus series merc. Have been told its 300 hp. Just wanting to put in the best fluid I can.

Chris

Amsoil Marine 75W-90.

https://www.amsoil.com/p/amsoil-synt...be-75w-90-agm/

Volvo Synthetic lube. Pricey.

Do you think this would be good in TRS drives as well?

I've always run the merc stuff!

In my 5s the merc stuff turns into water , super thin after a few weekends.
In my 6`s merc fluid expands and foams like crazy, thought there was something wrong with the drives but it was confirmed that is normal with the merc stuff.

Amsoil doesnt do any of that and I always had way less fuzz on the magnets .
Sorry but the merc stuff is junk

what weight do you run?

I agree the Merc HP green oil is junk. Their newest Merc Xtreme Performance Amber color oil is much better.

75w110

Simply use what the manufacturer spent $$$ billions on in R&D.

The merc amber oil is what I was told to use and always run

And what in the heck single item have they spent billions on ? :)

I know us boaters have spent billions on the junk Mercury peddles!!!!

Amsoil severe gear

Remember boys, the OP asked for an Alpha, not Bravo's or SSM's.

I had personal experience with the Amsoil Marine 80W-90 in an Alpha as that is what I used to put in a buddy's boat with a 5.0L/Alpha when I took over doing his winterizations. One year, he lost a shift shaft seal and didn't know it until the gear lube in the reservoir was caramel milkshake. Had another buddy that was a Merc tech at a local marina replace the seal and he went ahead and disassembled the drive to check everything out and better yet, thoroughly clean out all the milkshake. Gears and bearings all looked good (I believe the drive had around 800 hours on it at this point). So Amsoil's claims of it being able to handle a good percentage of water contamination are valid and proven out in a real life scenario.

I believe the drive had almost 1,200 hours on it when my buddy sold the boat. It was still going strong.

There's been lots of testing on rear diff hypoid gears tearing up the muloviscosity chains. It essentially destroys the oil, and that may be what you are seeing...reduction of viscosity.
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+1 on the Amsoil Marine gear oil. Apparently, can take 10% seawater and still perform to max spec. Hard to beat that for insurance.

TRS would be good to go. No shifting in TRS drive internals.

Merc HP gear oil is straight 90W


https://cimg4.ibsrv.net/gimg/www.off...31dfcc789.jpeg

Interesting. Please share some links!

Have to apologize for how some of my spelling comes out. My phone likes to go back and change what I've typed...and I have to go back and sort it out...but sometimes I don't catch it.

It really reay happens on OSO forum...not sure why.
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I'll see if can dig up the test. It was more for Diesel rear diffs....but that applies to our needs for sure.

Hypoid gears are when you have a 90° direction change, and the input shaft center is offset from the output shaft center.

Ford 9" rear diffs...are closer to Spiroid gears...where the the in/out shafts are even further apart.

It's a factor because of the sliding action that has to happen.

The helical gears we use will be quieter and straight cut.

Superbikes have that straight cut gear whine...that we've all heard.

Heli gears are quiter in trannys etc...but they have end thrust.
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As an example, on my Arneson drives...the reduction gears that also drop the level of the output shaft, are heli cut. So the case deforms with high HP. You need to reinforce the casing to keep everything together. With that forces also comes less efficient power transfer...along with heat into the fluid.

Try this link...is has a link to the Amsoil commissioned study.

https://www.corvetteforum.com/forums...ne-amsoil.html


A lot of the original links don't work anymore from almost 20 years ago.