Lower unit gear lube question

[kbh121956]

1987 Force 85 hp. What is the proper gear lube used for the lower foot? I can't find any information on it in the service manual. Any brands better then others? Thanks.

 

[Nordin]

Most OB brands ask for their own brands such as Mercury (Quicksilver) Johnson/Evinrude (BRP) etc.
You can use this BUT it is expensive.

Importent is to use oil that is no aggressive to yellowmetals (brass/bronze bushings).
I use Automotive gearoil SAE 80-90W EP (no aggressive) API GL4 or GL5.
It is much cheaper than Merc., BRP or the brands that the japaneese suggest for there OB.

 

[jerryjerry05]

Any 80-90 will work.
I use Wally World oil.
NEVER had a problem.

​The more expensive oil is good but if it gets water????
It's no better than the cheap stuff.

You just have to make sure the seals are good.
Do a pressure test.

The bottom drain plug on your motor is an allen head set screw.
No matter what I did, I couldn't get mine to seal right.
They would weep a small amount of water.

​Just keep a close eye on it.

 

[kbh121956]

So it does not need to be "marine" grade, just as long that it has the GL4 or GL5 rating? That does save some serious dollars. Thanks guys. I'll consider this thread closed.

 

[robert graham]

So it does not need to be "marine" grade, just as long that it has the GL4 or GL5 rating? That does save some serious dollars. Thanks guys. I'll consider this thread closed.

It has to say "Marine Lower Unit Lubricant".....Walmart brand is fine....or any brand is O.K....

 

[Nordin]

Oil can be discussed forever, many different comments.
Marine grade yes or no, what are the different.

The marine grade may separate the water from the oil, the automotive maybe not.
If it is aggressive to yellowmetals do not use it because there are bronze bushing int the Chrysler/Force LU.

I have read datablade from Castrol and they have an SAE 80-90W for car gearboxes.
For sale in 1 liter bottles or 4 liter bottles.

Last line in the datablade says "Also for sale in 200ml tubs as outboard gear oil".

I use Automotive typ SAE 80-90W and change it every autumn if it is contaminated of water.

 

[Jiggz]

Like Jerry, I use Wally World SAE 80-90W! It works.

 

[kbh121956]

Thank you all for the reply. The Supertech (Wally World) 80W-90 extreme pressure will then work fine? The bottle states API GL-5. The bottle does not have Marine printed on it anywhere. I have always changed the lower unit oil on my boats at least twice a season. I am new to the outboard though. Living in Utah, there are not any marine shops close to me. I did look for marine lube while at wally world but nothing. Utah's a drag when it comes to boating supplies. Again, thank you for the replies.

 

[jerryjerry05]

80-90 off the shelf.

I'm anal about checking the oil in my lower unit.
My new motor 2002 225 Mercury.
​The lower unit used starts at $500 and goes UP. $2500 new.

 

[Derrick Fronckowiak]

My understanding is "marine grade" means that the oil will emulsify if it gets water in it, thereby still providing lubrication to your lower unit even in the case of water intrusion. So when you drain your lower unit, if the oil looks milky or kind of thicker and gooey that means some water got in from somewhere. Is that right Jerry?

 

[Nordin]

The marine grade will separate water from the oil and if you drain the LU water will drain first then the oil, as oil float on water.

Automotive gear oil does not separate the water and then the oil will look milky if it is contaminated of water.

 

[jerryjerry05]

The oil turns black over time.
Any color change other than the original color and black??
The oil will work even if it gets some water mixed in.
​It's a problem after prolonged exposure and loss of the oil.
​I've seen contaminated oil just about white. No lubrication then.
The lower is supposed to be sealed to keep the water out and the oil in.
​A lower heats up from the use and the exhaust passing through.
​As it heats up, oil expands and pushes past the bad seal.
As it cools it contracts and draws water in and it mixes with the oil.

Even the high dollar oils will mix with water while the drives turning.

 

[robert graham]

Since they make Marine Lower Unit Lubricants with specific additives to help prevent corrosion why would anyone choose to not use it?....to save a few pennies on the cost????