Final Gear Oil Question

[FJJ'sR]

I have a quart of Bel-Ray 80W-90 gear oil left over from a previous bike I had and I was wondering if I could use the Bel-Ray gear oil in the FJR final gear case without problems?

I see that Mobil 1, 75W-90 and even 75W-140 have been discussed before. Is there a big difference between 80W and 75W? And is 75W-140 too thick? I live in MN. Does the ambient air temperature factor in for gear oil as it does for motor oil?

Just curious to learn. Thanks in advance for comments and help!

FJJ'sR

 

[reecebike]

As long as it says GL-5 or hypoid it will be fine!!!

 

[str8]

I knew this guy who used Bel-ray and his diff melted down. He was riding a BMW though.

+1 on what reece said.

 

[FJJ'sR]

As long as it says GL-5 or hypoid it will be fine!!!

It's API GL-5 -- Bel-Ray Gear Saver Hypoid Gear Oil SAE 80W-90.

Should I just recycle it and pick up some Mobil 1, 75-90 instead?

What's the best gear oil recommendation?

 

[Foxhuntr]

I just buy the Yamaha stuff that is recommended.

 

[str8]

Lots of reading here

 

[Fred W]

I see that Mobil 1, 75W-90 and even 75W-140 have been discussed before. Is there a big difference between 80W and 75W?

I'd say the difference is about 5W.

And is 75W-140 too thick? I live in MN. Does the ambient air temperature factor in for gear oil as it does for motor oil?
Just curious to learn. Thanks in advance for comments and help!

Seriously, first you need to understand what the two numbers are in a multi-viscosity oil. This applies equally to gear oil and motor oil. The first number, before the "W", is the viscosity of the oil when the oils are cold (as compared to a straight weight, non multi-vis oil). The second number, after the "W", is the equivalent to straight weight oil when up to full temperature.

So, a 75W140 gear oil is thinner when cold, but thicker when hot as compared to 80W90 gear oil at those same temps. Now, realize that any oil, no matter what it's viscosity, always gets thinner as it warms. That means that that our 80W90 oil changes its viscosity a lot more from warm to hot than the 75W140. In motor oils a stable viscosity is a very good thing. However, a thicker gear oil will generate more heat from internal friction within the moving lube, eventually heating the gear lube higher until it thins out more.

So the question remains: Does it matter?

Who the heck knows... Probably not. That's one reason this thread has already been moved to the NEPRT bucket.

Also, FWIW, Mamma Yamma specifies GL-4 lube (not GL-5). However, most of us just use the GL-5 as it is more readily available and doesn't seem to have any deleterious effects to the FJR final drives.

Y gearoil MV

 

[charismaticmegafauna]

So, a 75W140 gear oil is thinner when cold, but thicker when hot

Not quite. Multi-vis lubes operate on the principle of: 'getting no thicker than the low number when cold and getting no thinner than the high number when hot'. They tend (due to additives) to keep the same (stable) viscosity. They don't "change" viscosities.

Now, realize that any oil, no matter what it's viscosity, always gets thinner as it warms.

Some silicone lubes are "viscosity stable" over wide ranges of temps and are used as "viscosity standards".

That means that that our 80W90 oil changes its viscosity a lot more from warm to hot than the 75W140. In motor oils a stable viscosity is a very good thing. However, a thicker gear oil will generate more heat from internal friction within the moving lube, eventually heating the gear lube higher until it thins out more.

And..., that 'friction' takes power (albeit small) to overcome. Thus, the lightest viscosity lube that satisfies the manufacturer's recco is (often) the most efficient.

Heavy (high viscosity) lubes are, usually, only recco'd for extreme, high load, situations.

'FJJ'sR': ...Does the ambient air temperature factor in for gear oil as it does for motor oil?

With respect to the FJR: ambient air temp has very little (if any) effect on the engine's oil (once up to operating temp). There exists an oil-to-coolant heat exchanger which tends to keep oil temps the same as coolant temps -- and coolant temps are controlled at: between stat closed/open and fan/s off/on.

Rear-drive gear oil may vary some (small...) due to ambient temps -- but, high loading of the rear-drive power transfer would have a more marked effect.

 

[wheatonFJR]

I love these threads. :clapping:

 

[Fred W]

So, what did I say that was wrong?

 

[FJJ'sR]

Lots of reading here

Okay I looked at the link.

I see that there's Yamaha Shaft Drive Gear Oil SAE 80W-90 API Service GL-4, GL-5.

And then there's Yamaha Drive Shaft Gear Oil (part #: 9079E-SH001-00) which states on the bottle: "By using special synthetic additives, improve & protect heat-resistant pinion gear for dynamic sports touring FJR1300."

I conclude that 80W-90 oil is okay. But what about the, "special synthetic additives, improve & protect heat-resistant pinion gear"?

I believe this oil has been referred to as, "Whale ****" before on this forum. Is there a special synthetic additive that's necessary for the FJR, or is this marketing hype?

Thanks for all the input!

 

[str8]

I've got the Bel-ray and the FJR stuff. Also have the Honda version. Used them all and my bike and it still rolls. I like to use different colors of oil in my rear end depending on my mood.

Right now I'm using the Honda stuff because everybody knows that Honda's last the longest right?

 

[08FJR4ME]

I've got the Bel-ray and the FJR stuff. Also have the Honda version. Used them all and my bike and it still rolls. I like to use different colors of oil in my rear end depending on my mood.
Right now I'm using the Honda stuff because everybody knows that Honda's last the longest right?

Still got mine and she starts rite up.

 

[Patriot]

All my bikes that spin a big shaft, but don't shaft me use synthetic Mobil 1 75w90 and I've been very happy.

No rear end explosions, but the occassional cough, sneeze, and fart that normally comes from a woman Italian bike is welcome. (my wife is Italian and I name all my bikes female Italian names.

Your BelRay 80w90 is just fine if you want to use it. I like synthetic (don't know if that's synthetic), so for the $8 I personally would change, but that's just anal me.

Cheers,

Mike in Nawlins'

 

[SockMonkey]

Personally, I use the Pro Honda 80W90 hypoid gear oil. Hey, if it's good enough for a Goldwing...

 

[FJJ'sR]

All my bikes that spin a big shaft, but don't shaft me use synthetic Mobil 1 75w90 and I've been very happy.
No rear end explosions, but the occassional cough, sneeze, and fart that normally comes from a woman Italian bike is welcome. (my wife is Italian and I name all my bikes female Italian names.

Your BelRay 80w90 is just fine if you want to use it. I like synthetic (don't know if that's synthetic), so for the $8 I personally would change, but that's just anal me.

Cheers,

Mike in Nawlins'

Thanks. I think I'll use up the rest of the Bel-Ray (2x changes) and then switch to Mobil1. The bike's got 1,450 miles on it now. When winter's finally over here, I'll do a rear gear oil change along with the engine oil.

 

[Bearly Flying]

I believe this oil has been referred to as, "Whale ****" before on this forum. Is there a special synthetic additive that's necessary for the FJR

Odot has the market pretty well sewed up for Whale **** and Seal Oils, You can try PM'ing him to see if he will sell you some.

He's a little weird, But being the "Only Gay Eskimo on this Forum" , We cut him some slack.. :wacko:

 

[Mike-H]

I believe this oil has been referred to as, "Whale ****" before on this forum. Is there a special synthetic additive that's necessary for the FJR

Odot has the market pretty well sewed up for Whale **** and Seal Oils, You can try PM'ing him to see if he will sell you some.

He's a little weird, But being the "Only Gay Eskimo on this Forum" , We cut him some slack.. :wacko:

The pot calling the kettle black.....so to speak :grin:

 

[odot]

You guys got it all wrong. I use the whale oil the way y'all use monkey butt powder. And seal oil...well, I just eat that with dried salmon. Oh, and a pinch of salt.....