Gear oil question

[Cornbread9]

So my 87' 2 stroke Yamaha Pro 50 outboard calls for SAE 90 oil in lower unit. I asked my brother to pick me up some on the way over as he was passing Advanced auto parts on the way over. He brings me Lucas 85W-140 heavy duty trans and diff. lube It says "great for outboard final drives" on the bottle. I know Lucas makes good stuff. Does anyone know if it this is ok. I already put it in and didn't want to waste it as it is $10/bottle. Thanks for your help.

 

[Bamaman1]

Re: Gear oil question

You don't want to use the 85W-140 or any hypoid gear lube that's not specifically rated for marine use..

You could certainly get away with Pennzoil 75W-90 outboard motor lube, however. It's available in the marine section of WalMart for less than $6 per quart.

I use the pump to put the lube in the lower unit. It takes 33 ounces on the higher horsespower motors, but 32 oz. will usually overflow the top vent plug.

 

[tazrig]

Re: Gear oil question

Use what your manual recommends for oil or don't complain when your drive fails. Marine drive oil is designed to mix with water if you ever have a leak. This will potentially save your drive from catastrophic failure. For what you paid for your engine and what a new or rebuilt drive will cost you do you really want to take the chance???

 

[Silvertip]

Re: Gear oil question

If the lower unit is NOT leaking water there is no need to use a specific "marine" lube unless the engine is under warranty and if a specific lube is recommended. If it is leaking, then fix it. If the lower is leaking enough water that a marine lube is required, it can't possibly emulsify enough water to save the lower anyway. Use either one but it is not necessary to use the marine equivalent.

 

[Capt Ken]

Re: Gear oil question

If the lower unit is NOT leaking water there is no need to use a specific "marine" lube unless the engine is under warranty and if a specific lube is recommended. If it is leaking, then fix it. If the lower is leaking enough water that a marine lube is required, it can't possibly emulsify enough water to save the lower anyway. Use either one but it is not necessary to use the marine equivalent.

Incorrect. Marine lube will absorb up to 50% water and still keep its oiling properties. Regular gear lube will turn to jelly and is near impossible to get out of the gearcase whereas marine lube will drain easily. You never know when you might pick up some fishing line and cause a prop seal to leak water into the unit. No sense in being penny wise and pound foolish.

 

[mygrady]

Re: Gear oil question

Do like Bamaman says. Go to Wallyworld and get a quart of the 90 wt gear lube.(yellow bottle). I believe they also have the screw in pump with a hose attachment. Fill from the bottom plug hole until it runs out of the top hole. then screw in the top plug, then the bottom.

 

[tazrig]

Re: Gear oil question

Incorrect. Marine lube will absorb up to 50% water and still keep its oiling properties. Regular gear lube will turn to jelly and is near impossible to get out of the gearcase whereas marine lube will drain easily. You never know when you might pick up some fishing line and cause a prop seal to leak water into the unit. No sense in being penny wise and pound foolish.

^^^+1 Go to Walmart, buy the cheap stuff. (non marine) Eventually you'll help to put your mechanics kids through school and keep Tow BoatUS and or Sea Tow in business. Hey, do what you want... Somebody has to help support the economy.:facepalm:

 

[Cornbread9]

Re: Gear oil question

Thanks for the advice. I am going to get the "outboard motor hypoid gearbox oil SAE 90" that the manual suggest. As far as the prop seals. I am familiar with most auto repairs but new to outboard repair. I took my prop off and investigated and see the hub in the prop but as to the prop seal, I'm not seeing how fishing line can cause a leak. I guess I will learn soon enough. I know this old motor will spring a leak eventually.

 

[Silvertip]

Re: Gear oil question

Incorrect. Marine lube will absorb up to 50% water and still keep its oiling properties. Regular gear lube will turn to jelly and is near impossible to get out of the gearcase whereas marine lube will drain easily. You never know when you might pick up some fishing line and cause a prop seal to leak water into the unit. No sense in being penny wise and pound foolish.

And I repeat -- if a lower unit is leaking that badly you will see signs of that (or hear signs of it). I see you are associated with a Marine Agency so you have obviously seen highly emulsified lower unit lube that you need to nearly pull out of the gearcase. And yes -- that water would be mixed with "Marine Lube". It looks the same, behaves the same and smells the same. It just costs more because of the "Marine" designation. But -- as in all things, use what lights your fire.