Gear lube question????
 

I saw this on the tech part any thoughts???
Always had jet boats but last year I bought a boat with twin mercruiser outdrives. Always one to stay on top of maintainence I changed oil in both outdrives. I went to the local merc dealer to get the proper oil & he said mercruiser hipo oil (green) was the only oil to use so I bought & installed it. At the end of the season I decided to drain out old oil & install fresh oil in case it had become contaminated. The oil drained out of the drives ok but I thought it looked a little sludgy. The reservoir however didn't drain. Upon further investigation I discovered that the oil in it had turned to some kind of green muck. I had to remove both reservoirs, scoop out the muck, flush & clean lines to outdrives, & wash out reservoirs ! I should also tell you that I installed drive showers on both outdrives at the beginning of last year & I dont race the boat or run it very hard. I thought this might have been some kind of fluke or something but when I went to help a friend winterize his boat who was also using this green oil we found the same thing in his reservoir! It was then that we both decided to install Mobil One gear oil. Is this OK to use ? Has anyone else had this problem ?

Maybe the only buy Mercruiser oil pitch is simply to get you to only buy Mercruiser oil???? Is there any evidence that the gear lube you buy off the shelf at W. Marine or Boater's World is any less quality, especially if you change frequently? Are we being taken by the marketing blitzkrieg on a majority of mundane engine products? Could this be like the big scam of insurance companies where they feed off ones fears and sell unnecessary overbloated policies? Hmmmmm. Definitely a point to ponder...

thats wierd...

I run da green stuff all the time in my TRS

never seen any of it get sludgy.

hmmmmmm.

It sounds like you might have a seal leak. look at the O rings on the drain plugs. It's very common for them to leak. Its a good idea just to change them when you change the fluid. I will be using Amsoil. I seen it used in a 2.5 lower unit, after years of use it had shown little to no ware

Merc hipo gear lube
 

Lots of people swear by Merc gear lube. Me personally, I use nothing but 100 % synthetic AMZOIL GL4 in my Bravos. I change frequently as well.

There have been many threads on OSO about different lubes. It seems the common truth is that most name brands are pretty good and some may offer better properties than others.

The golden rule: Change often.

I have to side with the Amsoil. I run series 2000 75w90 in my alpha drive hooked to a SBC. The boat is a 86 and I have had it now 7 years...no problems the Gear lube still looks good at the end of season..

Any of the gear lubes mentioned in this thread are good to use in
Mercruiser sterndrives. The only issue you are going to have using a synthetic based gear lube is when and if you have water intrusion in one of your drives the water will not imulsify(mix with) the synthetic gear lube. So once you have water in the drive it will be a CATASTROPHIC FAILURE if it is not taken care of A.S.A.P. We have seen in the past a Bravo I running with big horsepower and no additional cooling as a drive shower literally turn Mercruiser's green gear lube into grease and fail a bearing inside the drive.Also if you mix standard brown Mercuiser gear lube with synthetic green you will get the same reaction as powergrudy did.

On our F1 race boat we found the Mobile One broke down under sever stress and heat. We've had better luck with Amsoil and Allison. Also a little Pro-Long seammed to drop the reistence and make it turn easier.
PS: Never had much luck with the Merc.