gl4/gl5

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schwartr88

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How can a gear oil be both gl4 and gl5 if the difference is in the amount of additives used?

I just bought some durablend 80w90 gear oil which is gl5 on the bottle but it says gl4 and gl5 on the website. I found out I need gl4 after I did some searching online.

In the last 2 hours I have read to many different opinions on this and have decided not to even bother with the change.
 
Good points and the Bigboys in the business are going to need to chime in....however, as I remember GL4 for manual transmissions with syncromesh setup and GL5 for Rearends.
 
A good question and one that is brought up many times.

Generally, a GL5 lubricant has the necessary level of EP and AW additives to be backward compatible with GL4 AND provide corrosion protection for most commonly used metals in differentials and Manual Transmissions.

Just remember, Manual Transmission lubricants and Differential lubricants are two different animals.

A manual transmission or transaxle usually has synchronizer assemblies of some sort that require special friction modifiers and viscosities that are compatible with the design of the transmission.

A number of companies, including ours, provide a number (4 flavors) of Manual Transmission lubricants for just about any transmission on the road, and include EP protection for both GL4 and GL5 API ratings.
 
What do you run in a car that has a trans/diff? I wrote to Mazda and they said not to use syn oil in their Protoge. Their reason was they had not tested it. Mine needs a change and I'm in a quandry as to what to use. Any suggestions would be appreciated.
Thanks Smoky
 
The reason I ask is I have a 2002 GM Sonoma. I have never changed the axel fluid (I cant do the front easily so Im skicking to the rear for now). The manual says to use GM part #1052271 80W-90 gear oil which is GL4, however it was replaced with another part # that I forgot.

Right now I have some durablend 80w-90 grear oil that is gl5 rated, and the web site says gl4/gl5. It also says approved for Ford, Mack and all Gl5 applications (gm is not listed).

Since Im a total No0b I just want to know if it is ok to use in my rear axel. I know and trust valvoline (plus it was only $1 a bottle due to a mistake).

Here is the product info:
http://www.valvoline.com/products/Durablend Gear Oil.pdf

I am only using this in the rear axel.
 
For a Sonoma it will work ok and the reason given by GM for not using synthetics is assinine in my view. Always use a GL5 in the diffys.

I just have a problem with their (Valvo's) low viscosity (thickness) of 14.7 or so viscosity. I believe a 75W90 should have a 100C viscosity of 18.0 cSt.

BTW, there is no reason it shouldn't work in the front diffy as well.
 
Hey MolaKule, between oil men, got a interesting client who required something interesting....

A Gear lubricant that has no EP additives(RP Synchromax) BUT, must be for a DIFF, why i say no EP additives is because apparently the EP attacks the bronze in the diff.OLD Vehicle, very old....
Amsoil have anything??
What you recommend?

And it has to have Film strength, or else it will fail so, because no oil toughness....

Idea's????
 
quote:
if a gl4 is *required* wont gl5 do harm
Click to expand...
Someone asked Mobil that and they replied that at transmission fluid temperatures normally occurring during street driving (not racing), there was no danger of corrosive wear when using current GL5 spec fluid in a transmission calling for GL4 fluid.

If in doubt, go with what the manual states -- even if it's only for peace of mind.
wink.gif
 
quote:
But hypothetically speaking: if a gl4 is *required* wont gl5 do harm.
Click to expand...
NO. As a person who deals daily with modern additives and their chemistry, today's EP additives come with metal deactivators and corrosion inhibitors.
 
Achilles,

See my response above.

I did develop some GL1-3 formulations for Bentone drives and worm gear type drive at about 90 weight.

Our HDS-5 gear Lubes have metal deactivators and corosion inhibitors that prevent the S-P from attacking metals of all types.

In the past, some of the olefin sulfides that were of the "activated" type would stain and pit copper alloys but I doubt they are used today.
 
There were a number of posts here years ago that stated the apparatus to certify GL-4 no longer exists. I can't remember who posted the info though.
 
OK, I have just one more idiot question.

The product sheet for durablend says:
Approvals/Performance Levels
Ford M2C108C
Mack GO-G and GO-H
MIL-PRF-2105E
API Services GL-5, GL-4, MT-1

It does not mention GM at all. Does this mean its not a good idea to use in a GM or will it be ok since it says API services gl5/4?

Just asking because some other companies do not list specific manufacturers just the fact it is gl5.
 
Hey MolaKule, between oil men, got a interesting client who required something interesting....

A Gear lubricant that has no EP additives(RP Synchromax) BUT, must be for a DIFF, why i say no EP additives is because apparently the EP attacks the bronze in the diff.OLD Vehicle, very old....
Amsoil have anything??
What you recommend?

And it has to have Film strength, or else it will fail so, because no oil toughness....

Idea's????

Off the shelf chevron borate gear oil's called delo ESI.

work for what you want
bruce
 
Al I believe Blano stated that.

How about the Amsoil 75W90 GL4 Manual Trans Gear Lube for the Diff? Email Tech Services to see.
 
"As a person who deals daily with modern additives and their chemistry, today's EP additives come with metal deactivators and corrosion inhibitors."

While very true the problem I see is NOT doing a OCI as required at perhaps 30K-50K or so. The additized and inhibited AW/EP package WILL due to normal oxidation LOSE some or all depending on time and temp the anti corrosive and yellow metal inhibiting properties. Chevron Borate technology seems to buck this trend tho.

bruce
 
Bruce and Mola,

So this means if using for example MTL-P from SF as i do. I need to exhange in between 30k-50kmiles to be sure that the manual gearbox dosent suffer damage due to the fact presented by bruce.

One advantage as i see it is that SF fluids has no viscosity improvents. Doesent this help the fluids to last much longer compared with for example Castrol SMX-S which have an viscosity index around 160 if i remember it correct.

Please elaborate.

Regards Johan
 
In our case we include EXTRA metal deactivators (MD's) and corrosion inhibitors (CI's) over and above the MD's and CI's that are formulated into the EP additive from the add manf.

The only problem I have seen with the Chevron Potassium Borate add is that if it is used with diesters, one gets moisture intrusion over time.

So if you're going with a full synthetic gear lube formula, it's best to use POE's with the KB's.

Right Johan, most of all our fluids have minimum VI's of 160. In high pressure areas such as gear teeth and reactive loads in bearings, VII's tend to shear so I prefer to formulate using no VII's, but instead use heavy duty PAO's and esters which inherently have high VII's and resist shear.

Our OCI recommendations are to change every 30k miles WITHOUT UOA's, OR to use the recommendations of the Oil analyst for further operation past 30k miles. This assumes the analyst said the oil was fit for operation past 30,000 miles.

We have tested out to 50k miles in Fleet Farm trucks and the analysis showed it was fit for at least another 30k. So that is why we say 30k OR Analyst recommendation with a UOA program.

You should see the abuse a 5- or 10-ton farm truck gets from a 14-year old farm boy hauling wheat or milo! Yikes!
shocked.gif
 
MolaKule, I thought a GL-5 lube has *more* EP and AW than a GL-4, and is therefore better able to handle the stresses of a diff rather than a tranny (hypoid versus helical cut gears, for example).

Not true?
 
"MolaKule, I thought a GL-5 lube has *more* EP and AW than a GL-4, and is therefore better able to handle the stresses of a diff rather than a tranny (hypoid versus helical cut gears, for example)."

correct while both GL-4 and 5 have S/P Anti scuff aditives the GL-5 has a higher leveal and will reduce spalling, pitting, 2 body and adhesive wear much better than the GL-4.

bruce
 
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