Good white paper on gear oil specs GL-4, GL-5.

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bottom line for me....


What is the viscosity of Pennzoil Synchromesh in traditional API weight?



Forget about the weight and think Kinematic Viscosity. The SAE grade system is ambiguous.

But.... a 75W90 MTL has a Kinematic Viscosity close to 14.5 cSt, which is what you need.

So the Pennzoil Synchromesh is not thick enough for your Golf's transmission.

The Amsoil MTG, the Redline MT-90, or the Castrol Syntrans Multivehicle 75W-90 has that viscosity.
 
Originally Posted By: antiqueshell
I looked closely at the Syncromesh data sheet and NOWHERE on it does it state it meets API GL-4 specification.



No it doesn't say that specifically.

But as I stated before, the additive package conforms to a GL-4 protection level additive package.


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Does Pennzoil Synchromesh pass the

ATSM D-130 copper corrosion test with a
1a or 1b classification.




All MTL fluids must pass as a minimum the 1B test.

Metal inhibitors are part of the additive package.
 
Originally Posted By: MolaKule


All MTL fluids must pass as a minimum the 1B test.

Metal inhibitors are part of the additive package.


How about GL-4 spec oils which rating do they need to meet to get that API spec on the ASTM D-130 test?

1a, 1b, or which?
 
Originally Posted By: antiqueshell
Originally Posted By: MolaKule


All MTL fluids must pass as a minimum the 1B test.

Metal inhibitors are part of the additive package.


How about GL-4 spec oils which rating do they need to meet to get that API spec on the ASTM D-130 test?

1a, 1b, or which?



You're confused again and mixing up terminology.

Society of Automotive Engineers, the SAE, defines the GL-X protection ratings for gear lubes.

American Society for Testing of Materials, the ASTM, defines most of the bench type mechanical and chemical tests.

The API deals mainly with motor oils.

Since we're discussing MTL's, why bring up generic GL-4's?
 
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Actually GL-4 seems to denote safe for yellow metals. Correct?

In order for that oil to meet GL-4 it also must pass the ASTM D-130 test with certain standards for corrosion. There is 1a, 1b, 2a, 2b, and so one.

It seems that a number of recent GL-5, MT-1 oils are capable of meeting that ASTM D-130 test with the second least corrosive result 1b.

So I would guess that GL-4 oil would need to pass with a 1a? Correct?
 
Originally Posted By: MolaKule
Originally Posted By: antiqueshell
I looked closely at the Syncromesh data sheet and NOWHERE on it does it state it meets API GL-4 specification.



No it doesn't say that specifically.

But as I stated before, the additive package conforms to a GL-4 protection level additive package.


Quote:


Does Pennzoil Synchromesh pass the

ATSM D-130 copper corrosion test with a
1a or 1b classification.




All MTL fluids must pass as a minimum the 1B test.

Metal inhibitors are part of the additive package.
 
Originally Posted By: MolaKule
...................For the majority of light truck and passenger car vehicles with Manual Transmissions, a GL-4 rating is all that is needed.

There are exceptions such as Subaru which apparently specs GL-5 MTL's, but they are the exception, so why should I make a GL-5 MTL when the market would not currently support an exception.

I suspect that in the future if and when Suburu's become more numerous and stay in the market, more companies will supply GL-5 and dual rated MTL's.


Motul Gear 300 75W90 is rated as API GL4 and GL5 / MIL-L-2105D and described by MOTUL as appropriate for use in: "All mechanical transmission, synchronized or not synchronized gearboxes, gearbox/differential, transfer gearboxes and hypoid differentials without limited slip system operating under shocks, heavy loads and low revolution speed or moderate loads and high revolution speed."

http://motul.speclube.com/products/all-products/gear-300-75w90-1l/

Do you know of other dual rated GL4/GL5 gear oils suitable for use in synchronized manual transmissions?
 
There are plenty of boutique producers around that offer great GL-4 MTL fluids. Rockland Standard Gear has a sm150 that I've used in my 6-speed Mazda and it's [censored] good. Seems people only focus on the big guys like RP, shell, castol, etc. and totally ignore the boutique guys that offer great products.
 
Interesting comments, and yes, my paper could be updated, but I did not try to differentiate GL-4 from MTL. That is another story. Most of the MTL products are thinner than what is required in classic cars, which is what I was specifically targeting.

My main point is that a GL-5 is overkill for the transmission and, from experience in many root cause analysis and UOA, I can very easily confirm that GL-5 in a manual transmission will wear down your synchronizers. I have seen car manuals and oil advertising that says you can use GL-5. Yes you can. But from my experience you will pay dearly in performance and repairs.

A couple of weeks ago the service guy from Mitsubishi wrote to me to ask why the transmission got hard to shift when he did the first change from factory fluid to GL-4 SAE 75W-90. Of course my answer was easy. Mitsubishi recommends a GL-3 SAE 75W-80 in those transmissions. He changed to that fluid and became a happy camper.

Europe uses mostly SAE 50 Diesel or TO-4 fluids in aftermarket services for transmissions. There is a Lubrizol study on that.

There are no MTL's in this market. One of these days I'll probably be the first to launch it, but there are bigger issues at the moment. For those that need MTL, I use a 5W-30 CI-4 group IV Synthetic and people are so happy with the results that I leave the MTL battle for later. MTL's carry about $100 premium over traditional GL-4 (wholesale drum).

My qualifications are 17 years in this business, lots of on-line studies and Chevron courses, about 5000 UOA, and dis-assembly or inspection of dozens (maybe hundreds) of engines and transmissions for root cause analysis.

I look to Molakule and various associates in Linked-in for the chemical details of what I see in the field.

That paper is the English version of one of 120 papers I've written on maintenance.
 
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Originally Posted By: camelCase
There are plenty of boutique producers around that offer great GL-4 MTL fluids.


Yes, this is what I found too!
I'm currently using a small italian company oil that is working greatly in my synchronized box, that is a GL-4, full synth, 90 @ 40°, 14.7 @ 100°, 160 VI and EP rated.
 
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