lower unit oil vs. gear oil

[zzimmer3]

I've done a search without success, searching for the difference between regular gear oil and lower unit oil. is there something in the oil since its used underwater?

just to make a point, I just spent $900 getting the lower unit rebuilt-so i'm not taking any shortcuts, I've just wandered for awhile.

thank you in advance for the input.

 

[matt167]

Re: lower unit oil vs. gear oil

It's all spec GL-5 unless you’ve got an old electric shifting OMC. I think it's marketing but I still grab OEM quicksilver gear lube just because

 

[Bt Doctur]

Re: lower unit oil vs. gear oil

Shame, if it is a Merc ,you could have had a new lower for $600.00 and with a 3 year gaurantee

 

[seahorse5]

Re: lower unit oil vs. gear oil



Here is a picture of various lower unit oils and how they hold water after 24 hours. This is from a Bass and Walleye magazine article a few years ago that tested all the common oils.

 

[82rude]

Re: lower unit oil vs. gear oil

according to one of my older manuals do not use auto-type gear-oil as it doesn't have anti foaming or anti- expansion qualitys to it which is necessary in a marine lower unit.

 

[TD_Maker]

Re: lower unit oil vs. gear oil

Just do yourself a favor and buy the best MARINE GEAR OIL GL-5 rated you can afford. Stay away from automotive gear oil, because it will foam up like crazy inside of a gear box.

 

[seahorse5]

Re: lower unit oil vs. gear oil

Be careful of GL-5 lubes as many are not recommended for older gearcases or car manual transmissions as the additives will affect brass and bronze bushings and other parts.

That is one reason why Yamaha does not want their V8 & SHO Heavy Duty gear oil used in older engines.

 

[JimS123]

Re: lower unit oil vs. gear oil

I've done a search without success, searching for the difference between regular gear oil and lower unit oil. is there something in the oil since its used underwater?

just to make a point, I just spent $900 getting the lower unit rebuilt-so i'm not taking any shortcuts, I've just wandered for awhile.

thank you in advance for the input.

So just use the manufacturer's OEM marine lower unit oil. That's not a shortcut and you won't have to think about it later. Maybe it might cost $5 more than some generic oil, so what's the problem?

 

[mrmamiller]

Re: lower unit oil vs. gear oil

Click image for larger version. Name: Gear Oil mixed with water.jpg Views: 21 Size: 62.6 KB ID: 212202

Here is a picture of various lower unit oils and how they hold water after 24 hours. This is from a Bass and Walleye magazine article a few years ago that tested all the common oils.

So, is it better to have the oil and water separate or to have the water held in suspension with the oil? I guess if you want to pull the plug and drain off water, separation would be better. If not pulling the plug, I'm guessing water in suspension is better...I really don't know. Experts?

 

[zzimmer3]

Re: lower unit oil vs. gear oil

thank you all for the input, like I said , I was curious as to what made it different. thank you all.

 

[seahorse5]

Re: lower unit oil vs. gear oil

Water kept is suspension in the oil prevents corrosion on the gears and bearings, plus still has lubricating properties. If left in over the winter, the separated water freezes and damages the gearcase.

 

[MakoNY]

Re: lower unit oil vs. gear oil

Based on that picture, the Evinrude oils seem to hold it in suspension better.

 

[seahorse5]

Re: lower unit oil vs. gear oil

That is the Evinrude E-TEC oils that are designed for 3 years or 300 hours of normal use. That XR has been discontinued and the HPF-Pro is now recommended for all mechanical shift gearcases.

 

[fishcrazy50]

Resurrecting an old post. My 96 Yamaha 225 2-stroke's only requirement is Hypoid 90w as specified in the owners manual. It now wears and SEI lower unit has it was a reverse rotation, not standard. In contacting SEI they said to stick with GL-4 as GL-5 does not have the additives to protect the bronze bushing. Any 80 or 90w GL-4 will suffice. In looking at a pic you can see the automotive hypoid 90 performed as well as the premium Mercury/Quicksilver product.

 

[GA_Boater]

Resurrecting an old post. My 96 Yamaha 225 2-stroke's only requirement is Hypoid 90w as specified in the owners manual. It now wears and SEI lower unit has it was a reverse rotation, not standard. In contacting SEI they said to stick with GL-4 as GL-5 does not have the additives to protect the bronze bushing. Any 80 or 90w GL-4 will suffice. In looking at a pic you can see the automotive hypoid 90 performed as well as the premium Mercury/Quicksilver product.

No, ya don't.

Closed