Also, there are several things that need to be greased inside the extension box, assuming they are Stellings.

True dat.

front and rear u-joints, slip joint and carrier bearing.

Thanks Chris, I'll do that next time around.

Chris

I talked to the marina that does all of my service today, and they said that they will not put Amsoil in the drives, for liability reasons. They said that they will only use the Mercruiser Racing Oil. Will it be bad to go from the Amsoil to the Mercruiser Racing Oil?

They wont use "Amsoil" for what reason??? Is it because it is Amsoil or is it because they wont use anything other than the Merc Racing Oil???

Probably because they bought Merc HP lube in a 5 gallon bucket at a cost of about $8/quart and going to charge you full retail ($14) quart price.

They claim that since they are a Mercruiser dealer, than the Mercruiser oil is the only thing that they will use. They based this on liability reasons. They also said that they don't know much about the Amsoil. Frankly, if the Merc HP racing oil is good, I really am not dead set on Amsoil, esp. considering that the Amsoil is hard to purchase. I am not a racer, and don't run the boat very hard for long periods of time, so I would be curious to know the differences in the oil, and what the true benefits are with the Amsoil vs. Merc. HP oil? Thanks for the info Griff.

I have always run the Merc HP gear lube with no problems.

I guess someone is making out on my boat as I've had my out drive servied every 2 years or 100ish hours. Should I follow your owners manual suggested service interval................Nah I might even do it more often. Preventive maintenance does have a meaning after all, like it or not.

I'm just passing on what the Maintenance Schedule states in the owners manual I have. It's not my opinion, assumption, or inclination... just the facts as printed in black and white. I believe that would be preventive maintenance according to Mercury. I'm not telling anyone what to do, just supplying information. You're the captain do what you will with your boat. Heck, change it every six months if you want that's even better.