Rage

Merc states their drive lubes will still work if contaminated by some water like up to ~10% as does Amsoil for their AGM Marine lube. I once had an old outboard that before I repaired it had a persistant water entrance problem from a damaged water pump sealing surface at the drive shaft that confirmed this capability for the Merc lube.

I have been using Redline Shock Proof Gear Lube (Heavy) since 2006 on a new Bravo X1. At that time Redline application chart recommended it for drives. That chart is now gone and Redline currently says not to use this in drives. A post on a diffferent site reported catistrophic drive failure with the Redline lube do to water contamination.

My Redline lube last season tested with 0.5% water vs lab recommendation of <0.1%. and the lube did not look abnormal and the drive had just been rebuilt (do to excessive torque breaking a gear not water in the lube). It is easy enough to get some fishing line wrapped around the propshaft and cut a seal.

The Amsoil SVG appears to be the lube of choice to protect the gears in high hp Brave drives. Does anyone have first hand experience of running a drive with the Amsoil SVG that became contaminated with water?

Just trying to make an informed choice. Thanks for any input on the Amsoil SVG lube vs water.

dogturd21

I have used the Amsoil drive lube for many years with good results. The interesting thing is that even though its a fully sythetic gear lube, its the same price as most dino oil gear lubes, and frequently even cheaper.

At one time I used other Amsoil gear lubes and Mobil 1 gear 80w-90 gear lube, and I did discover that its important to use a lube with a tolerance for water.

Rage

So which ones had problems and which ones did not?

dogturd21

Both of them had problems, only the Amsoil marine gear lube (and other marine-specific gear lubs) did not have the problem.
I used a Amsoil Gear lube 80w-90 that was for automotive differentials, and a Mobil 1 same same. Both had problems where even a tiny bit of water would settle to the bottom and corrode parts of the gears. Obviously I had a small leak but it took me years to track down the source. One time I drained the oil after running it a while on the hose, and the milky crap that came out was quite scary- leaving it sit for a few hours in a 2 liter clear soda bottle showed that it was only about 1 ounce of water in 2 quarts of oil. It turned out that the cause was a bad lower shift shaft bushing that let water creep into the bell housing- as the drive cooled down it would pull water in via the drive shaft seal. this was only discovered when I pulled the drive immediately after the boat was pulled from the water- this time there was not enough time for the water to run out past the bad bushing. I had tested the upper and lower gearcases and never had problem, rebuilt both uppers and lowers myself, and still had the water problem. Well, of course I would- the bushing is in the bell housing, not the drive. The water problem was bad enough that I was changing the drive lube 3-4 times a season.

That said, the drive (Alpha SS with a 454 420 hp) is still going strong with all the original metal parts after 1700 hours.

Rage

Thanks. Great hours. So as I understand it the problem you had was rust. The marine lubes did not allow rust on the gears and the non marine lubes did. Did they all turn milky looking when the water was present or which did and which did not?

dogturd21

Both lubes turned milky when water was present AND the oil was highly adgitated, as would occur while the drive was engaged. But the marine lube would keep the water in suspension for days, while the non-marine lube would allow the water to seperate in minutes or hours. So the marine lube protected agains corrosion far better, and it allowed all of the water to be removed during a drive oil change. The non-marine lube always had the danger of leaving some water in the drive after a change, or the danger of corrosion when the water seperated out. Obviously the danger depends on how much water gets in there- I was suffering from 5%-10% water during the worst events.

I think this is an important attribute of marine gear oils that is frequently overlooked.

Rage

That is the kind of detailed info I need. Thanks.

robby dmax

i agree was just looking at putting the redline in but after reading this i am going to use the amsoil.
thanks

dogturd21

Well, I like the Amsoil- its priced right, its a full synthetic, and does a great job. That said, whatever brand gear lube you prefer, I would recommend that its specific for marine use and can withstand water contamination.

Rage

Interesting independant test results on marine gear lubes:

http://bwbmag.com/output.cfm?id=1891729&sectionid=308