Lower Unit Gear Oil for 1984 Mercurycruiser260

[jwjbs]

I purchased a used boat this spring and although it appears to be well taken care of I wanted to go ahead and check and change the lower unit oil. when I drained the gear lube is was a thick green type of gear lube. The kind I remember as a kid on the farm with some equipment we used........looked like a real good gear lube. The oil I purchased to put in it was Sierra type lower unit oil that indicated it could be used on "all lower units". It was a light brown color and didn't look to be as heavy as a weight as the green oil/gear lube I drained. Since I'm new to boating am I being over cautious or is the green stuff better?

 

[Chris1956]

Re: Lower Unit Gear Oil for 1984 Mercurycruiser260

Gear oil for marine applications is pretty standard. Your gearcase is a mechanical shift type, so you need to use marine gear oil for mechanical shift motors. If that is what the Sierra stuff it, you are good to go.

Not sure what the green stuff is. Using too heavy of a gear oil can ruin the gears. Use the recommended stuff.

 

[chum1]

Re: Lower Unit Gear Oil for 1984 Mercurycruiser260

the green stuff is probably the merc. labeled gear lube found at walmart, good stuff.

 

[wellcraft-classic210]

Re: Lower Unit Gear Oil for 1984 Mercurycruiser260

The Mercruiser gear lube a great product ( perhaps the best ) but may be more Blue than Green if I am not mistaken. I have seen smaller amounts of water intrusion changing the color towards green on some units. Water can also cause the oil to thicken.

At any rate you may want to make sure the oil does not discolor from what it looks like when you install it.

Do a pressure & bellows check ASAP if it does.

 

[jwjbs]

Re: Lower Unit Gear Oil for 1984 Mercurycruiser260

The Mercruiser gear lube a great product ( perhaps the best ) but may be more Blue than Green if I am not mistaken. I have seen smaller amounts of water intrusion changing the color towards green on some units. Water can also cause the oil to thicken.

At any rate you may want to make sure the oil does not discolor from what it looks like when you install it.

Do a pressure & bellows check ASAP if it does.

I think I'll get the regular merc oil (green or blue stuff) and replace the sierra. It just seemed like a better gear lube.

thank you for all your replies.

 

[Don S]

Re: Lower Unit Gear Oil for 1984 Mercurycruiser260

It's called High Performance gear lube, not the green or blue stuff.