Gear lube info and cross referance needed

[zigbat]

1988 OMC 128 hp 2.3L Cobra

I just boight this boat this past spring..
Its my first boat and besides tearing it up and pushing it out of 8 inch deep areas of the river I dont have alot of other experience..

I am getting everything together to winterize it but I cant find what Gear Lube to use in the lower unit..
I think I read somewhere that OMC Hi-Vis is the recommended lube..
I looked it up on ebay and it will cost like 35 bucks for a couple quarts and I figure that there is something equivalent to the recommended manufacturer branded product that i can pump in that isnt quite so much..

Q. Is Hi-Vis the right lube for my boat
what is the equivilant if any to the recommended lube..

 

[Scott Danforth]

you could go to walmart and get the generic high performance marine gear lube for your 2.3 liter powered cobra

 

[zigbat]

Simple enough.. No GL5 synthetic or anything like that? I notices in the book that they love the GL5 Syn for lubricating just about every part when i searched for gear lube in my PDF book never did find the info in my book that way..

anyway, what viscosity or is that an all around gear lube walmart sells

 

[Scott Danforth]

it is GL5 marine gear lube.

I run synthetic in my DP. not needed in your cobra, however if you want to run syn, go for it.

 

[zigbat]

I am a big fan of synthetics..I have 10w40 full syn auto oil and full syn lucas stabilizer in the crankcase. I couldnt find SAE30 full syn (OMC recommends SAE 30) locally I went with the 10w40 because Volvo recommends Volvo brand 10w40 full syn marine so i bought 10w40 full syn minus the volvo and marine

let me ask this, is there a diffrence between auto gear lube and marine gear lube?
what do you run?

I know its an old boat, but it is very nice and has little use and was well maintained and I would like it to stay that way..

 

[vasy]

Gear Oil: https://www.amazon.com/dp/B001VMLF82
SAE30 Oil: https://www.amazon.com/Sierra-Synthe.../dp/B000N9LQH4

I use this gear oil: https://www.amazon.com/gp/product/B000QUN7GI
Seems to have good reviews but I have no had it in long enough to say anything, but ok so far.

 

[Scott Danforth]

I am a big fan of synthetics..I have 10w40 full syn auto oil and full syn lucas stabilizer in the crankcase. I couldnt find SAE30 full syn (OMC recommends SAE 30) locally I went with the 10w40 because Volvo recommends Volvo brand 10w40 full syn marine so i bought 10w40 full syn minus the volvo and marine

let me ask this, is there a diffrence between auto gear lube and marine gear lube?
what do you run?

I know its an old boat, but it is very nice and has little use and was well maintained and I would like it to stay that way..

Not going to turn this into an oil thread

Yes, there is a difference between automotive and marine gear lube. marine gear lube will still be useful if there is a bit of water in it. use marine gear lube

To answer your question on what I run..... Rotella T 15W40 in the motors and Amsoil marine gear lube in the outdrives. Rottela T is a diesel motor that still has zinc in it. I run it in all my motors (boats, truck, car, lawn mower, leaf blower, edger, etc) except one of my vehicles which runs 0W40 euroblend synthetic

your old overhead cam ranger truck / pinto motor in your boat could use zinc which the synthetics dont have, so I suggest the Rotella vs spending money on a synthetic. your OMC motor is not a volvo motor, so go off the oil recommendations for your OMC motor. in 1988 they recommended SAE 30 with a specific rating of SF or SG. not todays SM or SN oils. match the oil to the motor's needs not to your desires.

your gear box doesnt need synthetic as its a dog-clutch crash box that doesnt have much of a load on it. generic walmart brand GL5 marine gear lube is all thats needed.

if you want it to stay nice, spend money on stuff you need to spend money on, dont waste money on things you dont need to, and use the boat often

 

[vasy]

Interesting read on running diesel motor oil in gas engines:

Diesel engine oil has more additives per volume. The most prevalent are overbase detergent additives. This additive has several jobs, but the main ones are to neutralize acids and clean. Diesel engines create a great deal more soot and combustion byproducts. Through blow-by, these find their way into the crankcase, forcing the oil to deal with them. When you put this extra additive load in a gasoline engine, the effects can be devastating to performance. The detergent will work as it is designed and try to clean the cylinder walls. This can have an adverse effect on the seal between the rings and liner, resulting in lost compression and efficiency

 

[Speak]

Just use quick silver hi-performance lube - been rocking that in my cobra for years 17 bucks a litre.

 

[Scott Danforth]

Interesting read on running diesel motor oil in gas engines:

Diesel engine oil has more additives per volume. The most prevalent are overbase detergent additives. This additive has several jobs, but the main ones are to neutralize acids and clean. Diesel engines create a great deal more soot and combustion byproducts. Through blow-by, these find their way into the crankcase, forcing the oil to deal with them. When you put this extra additive load in a gasoline engine, the effects can be devastating to performance. The detergent will work as it is designed and try to clean the cylinder walls. This can have an adverse effect on the seal between the rings and liner, resulting in lost compression and efficiency

.........i guess i should have gotten a bit of compression loss over the past 3,000,000 driven miles then on all my vehicles (average 300,000 miles per vehicle) ..... Or the boat motors and small engines that i have been running it in for the past 30 years should have failed.....

The oil is CJ-4/SM rated ( for both diesel AND gasoline motors)

Just do a search for oil in the forums and you will see many members on this forum run rotella T

 

[Lou C]

As far as the gear oil, I've been using Merc High Performance gear lube in my '88 Cobra at the recommendation of my OMC trained mechanic for about 15 years, its easy to find anywhere and works great. Motor oil, I use the Merc 25/40 marine oil in my '88 4.3 which holds up as well as a straight weight (verified by doing a Blackstone oil analysis straight 40 vs Merc 25/40) over a few years worth of running. So there you have it, you will do just fine with Merc lubricants you can get at any boating store anywhere in the country.....