Gear lube for Merc

[Barefoot Bob]

In my Rude I always used high visc gear lube from OMC. What should I be useing in the Merc. Also wondering if all this gear lube is just alot of talk. What about using my good 80/90 gear lube that I put in my customers vehicals?

[sho305]

The idea is the marine lube can handle water to keep any corrosion in there away. It will keep the water suspended in the lube unlike the car stuff. It will still separate if it sits a while. There is a good chance of moisture getting in there if only in tiny amounts.

In my experience, changing the lube often is the best idea when you are running lots of power thru a gearbox. I know the Bravo I/O drives will stay alive a lot longer when you change it a lot with Merc fluid. I know guys with 500-800hp motors that swear by it and those who did not blew them. They changed about every 3-4 weekends of use. I think it breaks down faster under those overpowered conditions. Then it was $9k for a drive.

I like synthetics after break-in myself, though I don't have any hipo units right now I need to change often. I just drain it over winter and put new synthetic in anything I want to go fast, a quality lube for normal stuff. I change it more if it is leaking water of course, and I think the synthetic is a hair thinner making it faster.

Synthetic is a no brainer for something like my inline, if it adds a hp or two...it is only under $5 a year more to run it:) Free power. I want to add 10-20% synthetic motor oil to thin it more, but have not dared to do it yet as LUs are stressed pretty high. I was thinking of trying a duralube type permanent treatment additive in a small %. I doubt it could hurt it.

Once I ran my old ChrisCraft a couple times on regular diff lube that was thicker than 80/90, like 90/140? It slowed it down quite a bit. Only had a little summer left so I tossed a $7 gallon of that in instead after working on it. I have heard of putting graphite in gearlube too, but never done it. Saw a toyota with 320+k miles ran on graphite motor oil only...

On the other hand, I bought a stick shift car once that shifted hard and notchy. When I drained it mineral oil came squirting out of maybe 10 weight like water. Shifted better with the right stuff synthetic blend in there, and could not notice performance difference. That is a drag racing trick I guess, good for a couple tenths. That trans is shot now, but they are known to puke synchros anyway.

[Capt.Insane-o]

The best stuff I have found to date, when I first got my Viper together i tried everything and burnt it all but for the merc Hi perf. The sierra gear lube is junk, go with the merc and be happy. I even use it in my trucks/car.:cool:

[Barefoot Bob]

Who has the best deal on purchasing a gallon at a time. I service 4 units a year and my OMC dealer was selling me a gallon of High Visc at $26.00

[sho305]

I know the Merc stuff is good for hipo. I have used Valvoline and got some LubiMatic synthetic on sale in my low power rigs. It was $4 a qt in the winter.

I was getting bring-your-own-jug Merc lube from a dealer here cheap, but then I quit believing it was Merc lube.

[Barefoot Bob]

I told the Merc dealer I usually purchased a gallon a year. They have 5 gallons they will sell me for $65.00 It is alot of fluid but maybe I should just get that.

[Markus]

I am running Quaker State Synchron Fully Synthetic 75w/90 automotive gear lube.

I received it after having ordered the Itasca marine gear lube, so I checked with an engineer at QS. He told me that the marine and automotive products were identical.

[Barefoot Bob]

Thats good to know

[sho305]

I'll have to look for that 75/90. All I see is 80/90.

Faster:D

[Barefoot Bob]

He is from Sweden, its probably metric;)

I am going to check with my Wholesale oil supplier and see what they have. But I will probably just purchase the Merc gear lube so I know what I got. After all, I am pushing 1800 pounds through the water with a motor putting out about 250HP. So I better not mess around.

[Hooty]

I get the Mercury Hi-Perf from BassPro. I can't remember how much I paid but I do remember they're cheaper than anybody else I tried.

c/6

Hooty

[sho305]

Yeah, I remember those beater cars I had as a kid. I would take Dad's 3k mile drain oil and pour it in all the time; they burned enough to not have to change it....just a filter a year or so. Never had an oil failure on those 100k+ cars, never cared if I did for a couple hundred bucks either:) Sure smoked the tires off fast though:D Now I have too much invested to gamble.

Hmmm, metric oil....a whole new market! Bob! I could be a millionaire....:o

[stvhelm]

Amsoil series 2000 Racing gear lube. cant beat it with stick. it goes in blue, and comes out blue.

[Stoker100]

Great stuff for gears that get hot. It really coats and makes the gears super slippery. I run it in everything including my sportmaster. Been running it in my bravo one with 560 hp without a shower for a while with no problems

[sosmerc]

I put Amsoil GL4 synthetic in all my customer's stuff (as well as my own). Been using it for a number of years. I sell it for $17 a gallon. I've been happy with it, but then again, I change the gear lube in my CLE before every outing.....for the few precious hours a season I get to run my own boat, it's cheap insurance!!;)

[Barefoot Bob]

Hooty...Thanks, I will have to check my cataloge. I never thaught of looking there.


Helmut....Amsoil is a super oil. One thing I did find out about there gear lube in cars is. If the car is stored over winter, the oil doesnt coat the gears very well and they rust. I saw this on customers cars. And it might also be do to storing in a moist garage.


Stoker100...My friends all use E.R. and have great luck. My cousin has been using it for about 20 years and swears by it.

[Barefoot Bob]

Have you ever seen a problem with stored cars where it doesnt cling to the gears?

[sosmerc]

Sorry Bob, I have no experience with "stored cars". but I have heard (probably somewhere on these forums) that Amsoil doesn't "cling" to stuff very well during periods of storage. That scares me abit as I use Amsoil in all my stuff as well as customers. When I bring an outboard out of storage (or winterization) I crank it over with double mix (with the plugs out and ignition off) just to wet everything down well before actually starting it up. I just brought my own boat out of hibernation the other day and in addition to this double mix crank over procedure, I also did an injector pressure drop test prior to firing up. This confirms that all injector pairs are delivering approximately the same amount of fuel for a given pulse duration....and it sprays a helluvalot of fuel into the crankcase before the first actual start up. She started instantly and sounded fine....but have yet to put her in the water and have my first run for 2003. I'm no oil guru, and we sure hear a wide variety of opinions on the subject here, but I do believe that synthetic is probably a notch above the regular stuff....no matter what brand. ;)

[stvhelm]

http://www.amsoil.com/products/tgr.html

[stvhelm]

http://www.amsoil.com/proptour/index.htm

[Markus]

Most synthetic base stocks do not have the rust protection properties of mineral oil, which is why your Amsoil experience is not at all unlikely.

Actually, the most common reason why some high performance synthetic oils have not been through the TC-W3 test is their poor corrosion protection. This was especially true in the past.