Lighter Borate Gear Oil

[pjf]

I’ve found a used Suzuki manual transmission and transfer case with only 18,000 miles of use. I’m told that these two gear boxes have been sitting in storage for the last decade or two. I've just installed them in my restoration project, a 1989 Sidekick.

I believe that the transmission and transfer case contain copper alloy components that will be attacked by olefin sulfide additives in GL-5 gear oils. My aged service manual specifies SAE 75W90 GL-4 gear oil for these two antiques.

While this requirement can be satisfied with Amsoil and Redline GL-4 products, I want to use GL-5 gear oils that contain borate additives in place of sulfide additives. The only product that I have found is Chevron Delo Gear Lubricant ESI 80W90, which is non-synthetic. Unfortunately, my service manual approves of SAE 80W90 gear oil only when the temperature remains above minus 4 degrees Fahrenheit – a dicey proposition during a Colorado winter.

What lighter GL-5 gear oils without sulfide additives are available for my application?

 

[artificialist]

I have never seen a synthetic gear oil that does not contain sulfur as a main ingredient.

You are better off just buying Amsoil or Redline GL4 oil.

 

[pjf]

For preservation, I want to try the Chevron Delo Gear Lubricant first because:

• Chevron Delo Gear Lubricant ESI has a sulfur content of 0.028%
• Redline MT-90 has a sulfur content of 0.5%
• Amsoil MTG has a sulfur content of 1.34%

Is there any reason for recommending the synthetic sulfur-based GL-4 oils over the non-synthetic borate-based GL-5 oil?

 

[artificialist]

The sulfur in that kind of concentration will not harm anything especially with the other anti-corrosion additives are active.

That, and GL-4 almost always allows smoother gear changes than any GL-5.

 

[samson1]

I just installed Redline MT 90 in my MT Chevy Colorado 2 days ago and it shifts better everyday and would highly recommend it. Tried others and had cold shifting problems but loving this MT 90, well worth the price.

 

[oggb]

Redline or Amsoil GL-4.

Or synchromesh if you're in a bind, I suppose.

 

[pjf]

Originally Posted By: artificialist
The sulfur in that kind of concentration will not harm anything especially with the other anti-corrosion additives are active.

That, and GL-4 almost always allows smoother gear changes than any GL-5.

• The sulfur concentration in Amsoil MT-90 & MTL is 1.34%. Per Redline, typical GL-5 oils that we are to avoid contain 1.5% sulfur. How is a 1.34% sulfur concentration harmless when a 1.5% concentration is not?
  
  
• What anti-corrosion additives will prevent the sulfur from harming copper alloys?
  
  
• How does the API rating (GL-4 vs. GL-5) affect the smoothness of gear changes?

 

[MolaKule]

Quote:
•What anti-corrosion additives will prevent the sulfur from harming copper alloys?



Since this is a MT, I would use a MT specific gear lube.

In most gears oils, you have the primary EP additive which is a S-P additive and then a supplementary additive which may use a borate ester or a potassium borate additive.

Metal inhibitors, corrosion inhibitors, and rust inhibitors are added to prevent any attacks on metals.

 

[MolaKule]

Quote:
•How does the API rating (GL-4 vs. GL-5) affect the smoothness of gear changes?


The GL ratings are wear PROTECTION ratings for the class of service. GL-5 is mostly for hypoid differentials which need higher S-P additive levels.

Most GL-5 differential gear oils come in higher viscosities than do GL-4 oils, which may affect shifting in cold weather.


SInce most MT's use spur gears, the level of protection needed is only GL-4.

Another difference between GL-4 and GL-5 is the TYPE of friction modifier used.

See article below.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1231182#Post1231182

 

[pjf]

MolaKule,

In your White Paper, entitled "Synchromesh Manual Transmission Lubricants," you list two categories of manual transmission oils that have the viscosities that I want to use: synchromesh and 75W85. Within these medium viscosity categories, which MTLs use boron additives in place of sulfur additives?

Thanks!

 

[MolaKule]

None.

Both GL-5 and GL-4 use S-P additives as primary AW/EP additives. The difference is in the treatment rate and the use of secondary AW/EP additives.

The only MT specific gear lube that I am aware of that has a boron additive (about 50 ppm) is the GM Synchromesh synthetic.

 

[pjf]

Originally Posted By: MolaKule

The only MT specific gear lube that I am aware of that has a boron additive (about 50 ppm) is the GM Synchromesh synthetic.

• Do you mean GM Performance 12345349 Synchromesh Transmission Fluid?
• Is there a product sheet that lists its specifications, including the borate additive?

 

[pjf]

I left my 1989 Sidekick outside last night when the temperature dropped to 5-degress Fahrenheit. The temperature rose to the teens when I decided to drive it this morning. Here are the problems I've found with the 80W90 Delo Gear Lubricant ESI oil in weather this cold:

• The transmission felt vague and difficult to get into gear. To enter 1st gear, I had to be completely stopped.
• The transfer case could enter 4-High easily but not 4-Low. When I placed the transfer case into 4-Low, the shift lever bounced back to neutral.

An hour later, when the temperature reached the twenties (Fahrenheit), I tried driving my Sidekick again. The transmission felt notchy. After a mile, the shifting became smooth and normal. The transfer case was able to enter both 4-High and 4-Low smoothly and normally

Bottom line:

Unless I move away from Colorado to a warmer area, I will look for a lighter weight oil for my transmission and transfer case. 80W90 is too viscous in snow country when starting out in the morning.

Next steps:

The 2004 Chevy Tracker (Vitara equivalent?) Owner's Manual specified GM Performance #12345349 Synchromesh Manual Transmission Fluid. I plan to get the specifications for this oil. If it contains borate additives, I will experiment with this oil in my transmission and transfer case before the winter is over.

 

[MolaKule]

Quote:
Do you mean GM Performance 12345349 Synchromesh Transmission Fluid?

Is there a product sheet that lists its specifications, including the borate additive?



Your Delo is too thick and doesn't have the correct friction modifier for synchromeshes.

Yes, the GM Performance 12345349 Synchromesh Transmission Fluid is a 12.0 cSt fully synthetic fluid.


I have never seen a PDS but I have a VOA analysis from a formulator friend, so I know what's in it.

Borates, like ZDDP, are not a panacea additive but when combined with other additives, makes a good secondary additive.

Othe MTL's may contain borates but I have never seen analysis from those other lubricants.

Another fluid you might want to try is the Redline MTL70W80 which is about a 10 cSt viscosity oil.

 

[pjf]

Originally Posted By: MolaKule

Yes, the GM Performance 12345349 Synchromesh Transmission Fluid is a 12.0 cSt fully synthetic fluid.


I have never seen a PDS but I have a VOA analysis from a formulator friend, so I know what's in it.

Borates, like ZDDP, are not a panacea additive but when combined with other additives, makes a good secondary additive.

Per Chevron, Delo Gear Lubricant ESI 80W-90 has 280 ppm (0.028%) sulfur in addition to the borate additive.

What does your friend's VOA show as the sulfur content of GM Performance 12345349 Synchromesh Transmission Fluid?

 

[MolaKule]

Check your PM.

 

[pjf]

Originally Posted By: MolaKule
The only MT specific gear lube that I am aware of that has a boron additive (about 50 ppm) is the GM Synchromesh synthetic.

Boron must be quite an effective additive. Typical sulfur concentrations (15,000 ppm) in GL-5 oils are two orders of magnitude higher.

I notice that sulfur concentrations are much lower in oils with boron additives, such as Chevron Delo Gear Lubricant ESI and GM 12345349 Synchromesh. I interpret this to mean that oils with boron additives are friendlier to copper alloys due to their lower sulfur content.

 

[MolaKule]

Quote:
I interpret this to mean that oils with boron additives are friendlier to copper alloys due to their lower sulfur content.



No. It simply means that in addition to the S-P additive, they are using a secondary additive, which I have tried to covey a couple of times. Please re-read the two articles on gear lubes and the one on MTL's.

Why the secondary additive?

Here is why: The primary S-P AW/EP additives form a protective interface only after the friction surfaces get hot.

The secondary potassium borate, borated ester, or phosphoryllated borate additive works in the lower temperature regimes to provide enhanced low-temp protection and provides some additional friction modification for mpg.

 

[pjf]

Originally Posted By: MolaKule
The primary S-P AW/EP additives form a protective interface only after the friction surfaces get hot.

The secondary potassium borate, borated ester, or phosphoryllated borate additive works in the lower temperature regimes to provide enhanced low-temp protection and provides some additional friction modification for mpg.

I'd like to get additional information about this dicotomy between low and high temperature additives.

The producers of some borate additives do agree with your first statement that "primary S-P AW/EP additives form a protective interface only after the friction surfaces get hot." However, they claim that borate additives are not as temperature sensitive and will continue to provide lubrication at the high temperatures required to activate S-P additives. If so, then borate additives can replace S-P additives and in fact do so in certain lubricants.

Comments?

 

[Rand]

boron/borate additives are not the holy grail. you're focusing too much on that.

you need an oil thats thinner when cold for shift performance.
GL-4 usually have 1/3 or so of the wear protection additives that gl-5 has. VERY FEW GL-5 gear oils are suitable for transmission use.

Just use a good GL-4 gear oil in a 75w90 and you will be fine.

IF it still shifts poorly you can go one step thinner.

The only modern (stock)cars that require a GL-5 Gear oil are certain high performance cars and subaru MT's because the MT gear oil is shared with the hypoid Diff.

My personal recommendation is to quit focusing on boron/borate and just get a quality gl-4 and stop the obsession . Redline 75w85 or MTL should be great in that.

MT-90 may be abit thick. 80w90 conventional will be WAY to thick at cold temps for any kind of decent shifting.

Mola knows what hes talking about if you think you found an inconsistency in his post its most likely because he dumbed it down for us to understand.. or didnt want to write a book for your question.(or you misunderstood)