Gearbox Oil whats your thoughts?

[jerry book]

We have been running Mercury hi performance in #6 speedmasters and have had only 1 failure in 7 years. The case that failed had 50-60 hours on it.

[Danny Pigott]

OMC High Vis. with STP mixed in it. This is an old stand by. i used it in merc D units Konig units Yamato units. We used this for many years an never had a problem. I have got a merc. unit under a 3 cyl. omc FEH an it has not failed.Botton line is if you have got a good unit it will last, if its not it will fail.As far as speed gain i don't think it will make much differnce the water pump will put more drag on the unit than the oil can make up for other than the pumpless units. In the 50's my dad had merc. units converted to pumpless.

[Phil McDaniel]

I've been running the same thing Danny's running except I add some molybdenum disulfied. Same gears in a "D" unit since "81 and they haven't even laped in yet. Phil