rearend gear lube questions

[timalan]

WOW, I can't believe this is still a live thread.

Who says GL-5 is corrosive??? Where did that info come from.

I ended up using the lower Weight mobile one. FWIW. It is still in there and turning round and round. But soon to get changed for some more Mobile One. 'Cause No body really seems to know Anything about the FJR specific Gear oil. It is just FJR Gear oil... Milked from Whales last I heard.

Funny stuff.

OH yes, and there are plenty of reasons for rear end lube with out "putting stuff in your rearend"

 

[IBJanky]

I use Shell Rotella gear oil 80W-90 for the rearend of my '07 FJR

I also use the Shell Rotella 15W-40 oil for the engine.

No problems with either one. Both work great.

 

[jim oneill]

Whats the diff between GL-4 and GL-5 ? And what does GL mean?

 

[ionbeam]

API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications.

API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D and SAE J2360 satisfy the requirements of the API GL-5 service designation.

 

[GPRIDER]

I just bought bottle of the Mobil 1 75w-90 LS Synth Gear lube. It says on the back label that it exceeds requirements of API Service GL-5. Is this going to be okay? Ions explaination looks like the GL-5 is all right to use, but.........................

GP

 

[my2dogs]

I just bought bottle of the Mobil 1 75w-90 LS Synth Gear lube. It says on the back label that it exceeds requirements of API Service GL-5. Is this going to be okay? Ions explaination looks like the GL-5 is all right to use, but.........................
GP

I use Redline 75/90 in mine. It is the lube I use in Corvette rear gear. Works great.

 

[Fred W]

https://www.lubrizol.com/products/automotive-gear-oil/GL5.asp

 

[GPRIDER]

https://www.lubrizol.com/products/automotive-gear-oil/GL5.asp

Thanks Fred. Looks like I'm good to go with the Mobil 1 then.

GP

 

[dabimf]

Does anyone know the actual viscosity of the yamaha FJR specific rear gear oil?And I am asking because of the many synthetic gear oils some are 70-90 some are 75-140 etc. why did those of us who use mobile 1 synthetic , not pick a 140 version ? Just curious

Tim

I use Royal Purple gear oil in the shaft drive case. I use the 75w90 weight. The 75w140 weight is used in heavy truck rear-ends.

 

[pacoonass]

It's interesting to learn the Yamaha whale lube only has an 80W GL4 rating. A GL4 rating is less than the GL5 with respect to wear rates under specific loading during the ASTM testing procedures such as four-ball and others. These lubricants are made using sulfur and phosphorus chemistry to yield the extreme pressure capability. The lower number followed by the "W" refers to the actual viscosity at 0 degress F. The upper number signifies the viscosity at 212 degrees F. Thus the multi-vis range is possible through the addition of Viscoity Index improvers (additives) which act like a molecular "coil springs". At cold temperatures, the molecules of the VI improver shrink (shorten) to lessen their effective drag on the surrounding oil or lubricant molecules. At higher temperatures, the VI improver (additive) unwinds and is effectively longer which yields more drag on the surrounding lubricant molecules. Under high loads such as found in 18 wheeler tractor drive units, the lubricants get very high in temperature after a long pull upgrade, for instance mountain, etc. The top number specifies the viscosity rating at the higher temperatures which indirectly indicate a sufficient film strength between gear teeth. Hypoid gears are used in the transaxles which are comprised of a spiral pinion driving the associated ring gear below it's geometrical centerline. This orientation yields more ground clearance since the input shaft (hypoid pinion) is lower on the gear housing "pumpkin" than if it was a plain spiral cut bevel gear. Spiral bevel gear sets are placed geometrically on the centerline of the ring gear, thus have straight cut teeth verses the curved "spiral" found in most differentials. Back to the physical characteristics of the oil. Temperature or heat effectively lowers viscosity. Thus lower viscosity lubricants have less film thickness and may possibly permit boundary lubrication regimes, i.e. metal-to-metal contact. The sulfur and phosphorus are reacted into the additives which act as plating agents under high temperatures and pressures. Plating the ferrous metal surface ultimately protects it from galling, tearing, etc. The plating is sacraficial and will prvent wear under most circumstances. In the presence of water (condensation), sulfur and phosphorus can react to become acidic. Other additives must be added to neuatralize the acids developed through the reaction with water. Thus, it is wise to change extreme pressure fluids (differential fluids) every so often to prevent the associated corrosion associated with water. The propensity to "sweat" due to humid or moist air such as is found on the Gulf Coast of the US is a definate concern if the oil is not fortified sufficiently with detergent addtives to neutralize the acids.

Someone in an earlier post mentioned that using a higher vis oil like 80W-140 caused more internal fluid friction, which ultimately causes more heat and a higher operating temperature. Viscosity issues are self-correcting since it decreases with increased temperature. Therefore, it is wise to error on the high side if low temperature flowabiltiy is not of concern. Flowabiltiy is signified by the lower number, i.e.75W, 80W (vis @ 0 degrees F). This can be a concern in really cold climates. In higher temp climates, the higher 85W-140 presents no issues. The additive chemistry really doesn't come into play without high heat and extreme pressure. Good film thickness prevents the metal-to-metal contact.

In a prior post, someone asked if Mobil makes other differential fluids than the 75W-90. The answer is yes. They market a synthetic 80W-140 and several viscosity grades of mineral counterparts. Common vis grades for the mineral counterparts are 80W-90, 80W-140, and 85W-140. One can see the viscosity over the entire temperature range by plotting two points on log paper and drawing a straight line between.

I just purchased a new '08 FJR and plan to change the differential fluid before 200 miles for flushing purposes. I plan to use a heavier vis oil for the break-in period to prevent shavings from doing damage to internal components. The thicker oil gives the highest amount of film strength to prevent contact damage, and will be flushed more easily by fluid which exerts more drag on them while draining. At least that's my logic. Someone may think it's crazy, but they will have to counter my logic to prove otherwise.

One other note, virtually all additives are synthetic since they are manufactured chemically. It is amuzing that Yamaha included the verbiage "synthetic additives" on the oil container. It shows they really are not on top of their tribology game.

Hope this helps!

 

[dwhartwell]

Yamaha requires use of 80W GL4 based upon factory data. I just signed up on the Yamaha website and they had the

service data to download.

This is the reason if you need GL4 you should use it. After reading this and the fact that it should be GL4,

the Mobil One GL5 is on its way out.

APPLICATION

PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is designed for manual transmissions and transaxles of both American and import vehicles. It is formulated to be compatible with “yellow metals”, such as bronze, found in synchronizers and other transmission components

Question:

Will Sulfur in Gear Oil Harm Manual Transmission Synchronizers?

I want to change the manual transmission fluid in my 2002 Toyota Echo. Your 75W-90 gear oil (Mobil 1® Synthetic Gear Lube LS 75W-90 ) is a GL-5 rated gear oil, which it says can be used for manual transmissions. It also says that it contains sulfur and phosphorus, which are extreme pressure additives. Won't the sulfur in the gear oil eat away my synchronizers in my transmission? I am looking for a straight honest answer.

-- Rick Dow, Mason City, IA

Answer:

Mobil 1 Synthetic Gear Oil is recommended for all applications where a GL-5 lubricant is specified. GL-5 type lubricants, which have a higher level of additive chemistry, can be corrosive to yellow metals such as copper, brass, etc., and in these applications a GL-4 product is usually specified.

 

[Duff]

I can't believe I ACTUALLY read this thread!

Worse yet, I can't believe I posted to it too!

I run whats they tells me... why question the great and wonderful Mama-Yamaha Corp?

 

[BulletBrad]

Yup Yup Yup ......... what Duff said. Well that plus we stock all the MammaYamma stuff at work so it's easy for me to get it. One another note, I've always figured, if I use factory stuff and keep records on it, there is really no way a warranty claim can get fired back for using the wrong stuff.

 

[Fred W]

Question:Will Sulfur in Gear Oil Harm Manual Transmission Synchronizers?

I want to change the manual transmission fluid in my 2002 Toyota Echo. Your 75W-90 gear oil (Mobil 1® Synthetic Gear Lube LS 75W-90 ) is a GL-5 rated gear oil, which it says can be used for manual transmissions. It also says that it contains sulfur and phosphorus, which are extreme pressure additives. Won't the sulfur in the gear oil eat away my synchronizers in my transmission? I am looking for a straight honest answer.

-- Rick Dow, Mason City, IA

Answer:

Mobil 1 Synthetic Gear Oil is recommended for all applications where a GL-5 lubricant is specified. GL-5 type lubricants, which have a higher level of additive chemistry, can be corrosive to yellow metals such as copper, brass, etc., and in these applications a GL-4 product is usually specified.

How does this relate to the rear end of a Yamaha FJR? There are no synchronizers in the final drive. There aren't any in the motorcycle transmission either, but that is not germane.

So the real question is: Are there any "yellow metal" components in the final drive of an FJR that would potentially be compromised by a gear oil with GL-5 additives?

I believe that the answer is no, but I have not been inside the pumpkin, so there may be a bushing or shim made from bronze. My guess is that Yamaha specified GL-4 because the rear gear on a motorcycle qualifies as "light duty". i.e. Specifiying GL-5 would be overkill for this application. Why they feel they can charge extra for their Whale **** is strictly a sleazy marketing strategy. That's why they don't tell you what's in the bottle. However, industrious forum-ites have found the specs online.

Certainly, the overwhelming empirical evidence is that the FJR final drive is a pretty robust unit and many, many users have used other than the specified GL-4 gear oil and suffered no apparent consequences. Now if you were riding a BMW you'd be prudent to go with the specified gear oil to retain the full warranty coverage for the eventual failure. But not so important on our bikes, IMO.

 

[charismaticmegafauna]

<snip>....Now if you were riding a BMW you'd be prudent to go with the specified gear oil to retain the full warranty coverage for the eventual failure. But not so important on our bikes, IMO.

That's why some BMW rear-drives (more to come, I hear) are factory-fill -- lifetime (no filler plug) --- so you can't put-in the wrong stuff.

"Vee know vat vee are doink..." :blink:

 

[user 213]

That's why some BMW rear-drives (more to come, I hear) are factory-fill -- lifetime (no filler plug) --- so you can't put-in the wrong stuff."Vee know vat vee are doink..." :blink:

That only lasted for a couple of years, then they put the drain plug back. It's kinda expensive to drain the oil w/o a drain plug, not to mention a PITA.

Some good data in this thread. The only things I can add is that Yamaha specs the special diff fluid for "high speed" use. When pressed for an answer in person, the Yamaha tech guys at one of the events admitted that Yamaha considers sustained 75 mph to be "high speed". That covers most of us at some point.

The other item is non-FJR related, but might be of some use to members. A clutch type car diff will not like GL-5 rated fluids. The greater lubricity of the GL-5 gear oil will cause the plates in the diff to chatter. A GL-4 oil will prevent this. Any gear type diff generally won't mind the GL-5 stuff. Never seen any damage to the yellow metals with GL-5, but that's not saying it can't occur.

 

[Nightshift]

If you'd quit putting things in your rearend, you wouldn't need lube.

That's a reaaly good one !!!!

LMAO!! :lol:

 

[dwhartwell]

Question:Will Sulfur in Gear Oil Harm Manual Transmission Synchronizers?

I want to change the manual transmission fluid in my 2002 Toyota Echo. Your 75W-90 gear oil (Mobil 1® Synthetic Gear Lube LS 75W-90 ) is a GL-5 rated gear oil, which it says can be used for manual transmissions. It also says that it contains sulfur and phosphorus, which are extreme pressure additives. Won't the sulfur in the gear oil eat away my synchronizers in my transmission? I am looking for a straight honest answer.

-- Rick Dow, Mason City, IA

Answer:

Mobil 1 Synthetic Gear Oil is recommended for all applications where a GL-5 lubricant is specified. GL-5 type lubricants, which have a higher level of additive chemistry, can be corrosive to yellow metals such as copper, brass, etc., and in these applications a GL-4 product is usually specified.

How does this relate to the rear end of a Yamaha FJR? There are no synchronizers in the final drive. There aren't any in the motorcycle transmission either, but that is not germane.

So the real question is: Are there any "yellow metal" components in the final drive of an FJR that would potentially be compromised by a gear oil with GL-5 additives?

I believe that the answer is no, but I have not been inside the pumpkin, so there may be a bushing or shim made from bronze. My guess is that Yamaha specified GL-4 because the rear gear on a motorcycle qualifies as "light duty". i.e. Specifiying GL-5 would be overkill for this application. Why they feel they can charge extra for their Whale **** is strictly a sleazy marketing strategy. That's why they don't tell you what's in the bottle. However, industrious forum-ites have found the specs online.

Certainly, the overwhelming empirical evidence is that the FJR final drive is a pretty robust unit and many, many users have used other than the specified GL-4 gear oil and suffered no apparent consequences. Now if you were riding a BMW you'd be prudent to go with the specified gear oil to retain the full warranty coverage for the eventual failure. But not so important on our bikes, IMO.

Correct, there are no syncro rings but most all of us know that.

You state that Yamaha ""requires GL-4 because the rear gear on a motorcycle qualifies as light duty, hence no need for GL5."" This is conjecture on your part unless you are intimate with the design of the unit.

The point of the bits of information was to make a point coming from reputable sources. NOT "well I've been doing this or that for years and I've not had a problem"

Lastly, I found on the Yamaha site for the first time, specific information that states to use 80W GL4 gear oil. So, for what it is worth Yamaha is stating that GL4 is acceptable and GL5 is not. (correction, Fred W. is correct in that it does not state "do not use GL-5. This is my statement based upon the properties of GL-4 compared to GL-5. The intent is to convey that the Yamaha document does not list GL-5 as an alternative. And this is on my 07 where GL-5 has been available for years.) For many, it is ignored out of ignorance, you think you know better, or everybody else is doing it so it must be OK.

Each of us can decide what to do with that data.

I try to present data backed up by the manufacturer when I make statements like these. Hopefully it will make you give it a second thought. By the way, Royal Purple 75W-90 is a GL4 and GL5 gear oil without the additives that are corrosive to bronze and other yellow metals.

 

[Fred W]

The point of the bits of information was to make a point coming from reputable sources. NOT "well I've been doing this or that for years and I've not had a problem"
Lastly, I found on the Yamaha site for the first time, specific information that states to use 80W GL4 gear oil. So, for what it is worth Yamaha is stating that GL4 is acceptable and GL5 is not.

No. That is not what it says. Nowhere does it say that GL-5 is not acceptable. (FWIW I have had the same "Service Specs" pdf file in my possession since I bought the bike). It simply specifies "Oil Type SAE80API "GL4" Hypoid Gear Oil" as being appropriate. Just because GL-4 is specified does not necessarily mean that GL-5 is inappropriate.

 

[worldbound4now]

wow, fresh discussion on an old topic. Good to hear reinforcement of non-yamaha products.