GL4 verses GL5?

[Kevin in Texas]

What is the difference between the two?

Are there conventional GL5 rated oils? If so, would they be Group II, II+, or III?

What is the advantage of the GL5 over the GL4 oils?

If a mineral base oil that has the GL5 rating like the Chevron Delo gear oils , does this mean that the delo is an ultra pure Group 3 or II+ or II.

Also, what does everyone think of the Chevron Delo gear oil. It has some impessive claims.

 

[Spector]

GL classifications are not like motor oil ratings, that is in oil a SL is backward compatible with an engine calling SJ or SH etc. WIth gear oil if the tranny calls for GL-4 in most circumstances you should not use a GL-5. It could damage soft metals in the gears

 

[Dick in Falls Church]

Kevin wrote:
>>What is the difference between the two?

Are there conventional GL5 rated oils? If so, would they be Group II, II+, or III?

What is the advantage of the GL5 over the GL4 oils?

If a mineral base oil that has the GL5 rating like the Chevron Delo gear oils , does this mean that the delo is an ultra pure Group 3 or II+ or II.>>

There are conventional GL5 oils. I guess they could be any base stock--1 through IV.

GL5 is for extreme pressure applications. It has additives in it which are not required in GL4 applications. As a practical matter, GL4 is not as widely available on the shelf. In some blends, the extreme pressure (sulfur) additives found in GL5 blends can break down and attack yellow (brass/bronze) metals which can be found in some transmission. Some of the newer GL5 lubes are also suitable for use in GL4 because of the different additive package.

Years back, VW specified GL4 ONLY in the manual transmissions. But, if one went back in the shop area at most places, the only gear lube was a 30 or 55 gallon drum of the least expensive GL5 lube.

 

[widman]

The GL-4/GL-5 confusion is widespread. GL-4 normally has about half of the Sulfur/Phos. additive package of GL-5. GL-5 products often claim GL-4 performance, and in EP applications that is true. But it can interfere with the synchronizers and change the characteristics of certain metals. i have found that those GL-4/GL-5 products in Suzukis and Nissans where GL-4 is recommended, but put it in a Volvo truck ZF transmission and in 10,000 km you have turned the syncronizers into blue warped metal.
This is not the case with the Borate additive system. With Borate the product can protect GL-4, GL-5, and although Chevron does not state it, would probably cover the heavy duty/high angle GL-6 category because of it's 75 lb Timken Test.

 

[Bror Jace]

So widman, care to clear up the "corrosive" issue for us?

Are you saying that you can run GL-5 oils in a synchromesh transmission full of brass and bronze parts?

It doesn't sound like it.

--- Bror Jace

 

[Pablo]

To Bror => It depends on the additive package in the GL-5 - most synthetic GL-5's are relatively harmless to any metals in a modern gear box....

 

[MolaKule]

Well, I don't know what happened but last night I listed a GL5 additve package and it has since disappeared.

Anyway, what it said was the GL4 package had 30 to 50% of the levels of these packages. My theory is that if don't leave the GL's in the diffy or tranny over 15,000 miles, there will not be enough time for oxidation to create any strong acids and attack non-ferrous parts, GL4 or GL5.

Just curious, what Manual transmission parts are made of bronze, brass, or whathaveyou? All of the later MTL's I am familiar with have all steel parts with aluminum cases.

 

[Bror Jace]

Um, Molakule, there are currently TWO (2) active threads on gear oils and the GL5 issue. Your comments are in the other one.

I see what you are saying about the sulfur/phosphorous. Without an accumulation of moisture, the brass/bronze bearings and synchros are pretty safe. Point taken.

Oh, and when I say MTL, I'm talking Red Line's Manual Transmission Lubricant ... a lightweight gear oil in the 70W90 range.

--- Bror Jace

 

[MolaKule]

Thanks Bor,

Brain death comes early on Manday, Moonday, I mean Monday!

I just ordered some Redline MTL for my Nissan's Mtranny and hope it arrives before I
have to go on a trip.

 

[widman]

Bronze parts..... sometimes it is just the ring and yoke, but on a lot of manual transmissions it is the syncronizing cones.

 

[Bror Jace]

Molakule, you aren't the only one. In my post above I actually said "bronze bearings."

Has anyone actually seen a roller-bearing made of bronze?

I meant to say "bronze bushings" ... and I don't know if they are in manual trannies anymore. I had heard that they are in Land Rover trannies ... but the same company also used oil-soaked paper to cover their wiring.

I hear their wiring actually makes great candle wicks.

The applications I've actually seen bronze bushings in myself were non automotive anyway, but I could see how they could be still be used in some transmissions.

And yes, brass/bronze is still used for synchro rings/cones.

--- Bror Jace

 

[MolaKule]

Ah, here is the post:

Here is some data for 3 dino Hypoid GL5 gear oils as to average range of additives:

KV - 17.42 to 18.24 (100 C)
VI - 98-101

Additive EP Elements (% by weight)
Sulfur - 2.72 to 2.93%
Phosphorous - 0.11% to 0.12%
Chlorine - 0.02%
Nitrogen - 0.08 to 0.09%

Now for Schaeffer's and Redline GL's, you might see additional AW/EP stuff such as Moly and Antimony in less than 1% concentrations.

It was stated that GL4 gear oils have a milder EP additive package which amounts to 30 to 50% less EP elements than do GL5 oils.

Now, I consider these additive concentrations to be mild when comparing additive packages for
industrial gear lubes, which may have as much as >20% sulfur and >= 1% phosphorous.

 

[MolaKule]

I should also add that chlorine is being removed from most gear lubes.

 

[carl97ss]

"...I hear their wiring actually makes great candle wicks."

 

[MolaKule]

FYI:

Just received the Redline MTL for the Nissan's Mtranny and it infers
that other EP/AW agents, such as esters and moly, are replacing the sulphur and phosphorous
EP additives.

 

[MolaKule]

Installed the Redline MTL last night.

Mtranny in N-Frontier now shifts as smooth as silk but also has a more "crispy" shift feel.

Will sample at 5k and see if wear metals are reduced over Amsoil's TGR.

 

[Bror Jace]

Molacule, I look forward to seeing tests of Red Line's gear oils. I have used them with great results (excellent durability and low-temp shifting ability) for a decade but I'd love to see the lab results as well.

--- Bror Jace