Latest on 'new' API/ASTM 'GL-4'-like standards?

[pgtr]

Has anybody followed this, heard anything or have any inside scoop?

Seems like years ago API said the GL-4 standard was dead due to a lack of testing equipment for the old standard. But maybe a year or better ago I learned that they had submitted a new standard for GL4 to ASTM for "review and adoption". Checked again at api.org and the same ol' PDF w/ the same ol' line is still there... Hmmm.

Soooo I went to astm.org. (type in "lubricant" in their site search engine, it's rather 'humorous' what pops up..!). But when it comes to things like "GL-4" "spur gear" or "manual transmission" - I had little luck on much info. I did find "D5760-95e1 Standard Specification for Performance of Manual Transmission Gear Lubricants" which references other relevant tests.

Is 'THIS' the new standard for GL4 or superceding GL4?

If so, are any of the bleeding edge brands like Redline adopting it?

But all this confuses me. Is API 'still' awaiting approval from ASTM? Or are they just 'giving' this standard to ASTM and it will now or someday become the 'ASTM' transmission gear lubricant standard rather than API? Or has API ceased to care about maintaining a specification for manual transmission? (personally I think that is a bad decision on their part, they've already been marginalized on ATFs and they 'had' a good standard for manual transmissions, why walk away from it?)

It's interesting that the API standards with respect to motor oils and rear ends are substantial influential industry standards yet when it comes to transmissions, API seems to be marginalized. I understand many manufacturers having adopted their own (proprietary?) standards for ATFs and are increasingly using them in manual transmissions as well in recent years. But still there are millions of traditional manual transmissions that have been made over the years ideally suited to GL4 that would still benefit from a good current standard for (older?) transmission lubricants. I suspect this situation has forced many automakers to 'compromise' on recommending EITHER a GL4 _OR_ GL5 for their transmissions. In fact I would think a modern GL4 standard could be created for manual transmissions and encompass a variety of gear viscosities up to say SAE90 and fully take into account sychronizer materials, protection and such.

I occasionally peruse the 'bleeding' edge synthetic brands like Redline and they are still pretty much stuck w/ hanging onto the somewhat defunct GL4 standard. I presume this is for the simple reason that they 'still' have nothing better to go on. Or are any of these claiming D5760-95e1 compliance and I missed it?

Comments?

 

[Ken2]

Isn't the problem with GL-5 gear oils in a manual transmission corrosion of the yellow metals (bronze, brass) due to attack by the old style extreme pressure additives?

Many modern GL-5 gear oils have EP additives that do not attack the yellow metals. In this case, I'd check with the oil maker to be sure that they're OK for a manual transmission.


Ken

 

[unDummy]

http://www.swri.edu/4org/d08/Abstracts/gearoils.pdf

Funny how something is obsolete but still being used in new manual trans and outboards.
Also, some oil companies defunct products are probably better than others newer products. I'll stick with my old GL4 synth over any new GL5 gear oil in the same weight.

What we don't need is a new spec that sacrifices transmission life for extra MPG or reduced environmental impact(less EP/AW).


Whats the difference between old/new style EP/AW in transmissions? Any oil company out there willing to provide info? Do synths need less AW/EP than mineral oils for equal protection?


I have synchros:
D5760-95e1 Standard Specification for Performance of Manual Transmission Gear Lubricants
This specification lists the test methods and acceptance criteria for determining the acceptability of lubricants used in nonsynchronized heavy duty manual transmission.

 

[userfriendly]

Ken2;
What do you think of those manual trnsmission fluids that are used in tractor trailers.
They often use barium and/or with sulphur phos.
The coating effect of the Ba protects the parts from the ep package I would guess.
I would conclude from your above post that the GL-4s, what ever they are, do not contain corrosive EP additives.
Funny, they are the most often recommended obsolete lubricant classification.

[ September 20, 2003, 03:20 PM: Message edited by: userfriendly ]

 

[par]

My understanding is that stictly GL-5 fluids may be a problem in manual transmission (e.g. Mobil 1), but the fluids rated GL 2==> GL 5 (e.g. Amsoil series 2000) pose no problem whatever.

I've tried RL MT-90, RL MTL, Royal Purple, Amsoil and found that Amsoil was the best in terms of shifting and smoothness in my Tacoma.

 

[pgtr]

But Ken, that's exactly my point

- which of those "many modern" lubricants are safe and how do I know for sure? No offense but I think it would be much better to just read a bottle and know it's safe than depend on online discussions to infer safety. We know which motor oils are detergent - so why not which are ideally suited for manuals? If we (again) had a relevant standard in widespread use we wouldn't have to "check" w/ lubricant makers. This all just illustrates the need for a standard. I'd like for the to either fix the testing issues and re-validate them existing GL-4 standard or introduce a new one in it's place.

It boggles my mind that the original GL-4 testing equipment can't be re-created or a new modified GL-4 testing procedure be instituted w/ modern equipment.

There are two problems w/ a GL5 in a 'traditional' manual transmission as I understand it. Yes, one is the copper derived yellow metal corrosion issues. The other is the appropriate degree of friction for 'smooth' synchronization function. I've read where many are critical of GL-5 for being too slick to allow for ideal synchronization action. As for the GL-5 'safe' claims - are they safe forever or can those protective safety 'buffers' burn off or wear out over the years? Let's say a consumer dumps some GL-5 'safe' lubricant in their GL-4 hungry transmission. Years later is it still 'safe'? Not everyone is going to be AR about changes afterall.

I agree unDummy (thanks for the link) - I think a pure GL4 is uncompromising and considering human interaction w/ a manual transmission, very important (at least to me). Off hand I only know of 2 or 3 synth GL4s (1 or 2 of which are marketed as Marine oils) and 1 dino GL4 off hand... which is yours?

I share your concerns about any 'new' standard that might compromise quality for MPG. In fairness I understand many newer transmissions are specifically designed for tighter tolerances to allow for say an ATF as factory fill - not sure that's accurate. I'm told an ATF is not appropriate for say an old Muncie because it simply was not built for it tolerance-wise and would leak out potentially among other things. I'm not expert on these matters - just passing on what little I know.

For me the GL5s that claim to be 'OK' for GL4 type applications seem to be one compromise piled on top of another. First you get an unneeded EP capability. Then you get some sort of way to buffer or make the additive 'safe'. And where is the ideal level of friction for synchros in all of this? Even if some GL5s are safe, I've heard them criticized for being too slick for synchros which may result in an added degree of shifting notchiness.

For years now I have watched endless debates about motor oils rage on the net that go on and on and on. I really wish that more of that energy had been focused on gear lubricants.

On Monday I think I'll send an email to API inquiring about the status and future of GL-4 and their submission to ASTM. Maybe others can join in w/ thier own inquiries? Not a mail-bomb or anything negative - just inquiries as to 'whats up' so to speak. Afterall they've been talking about updating their defunct GL4 standard for a couple years now - I'd like to know if there's a light at the end of the tunnel!!!

What do you guys think? Maybe enough inquires and they might offer something more than a now years old PDF on their site that says GL-4 is old but something's been submitted...?

API.org Contact Us

 

[pgtr]

Whoops! Just noticed this and should clarify that according to API, the GL-4 standard is listed under "Service Designations in Current Use". So technically it is not a defunct standard as I and others have implied. That tells me that at best it is a functional spec that cannot be validated fully.

FYI: The GL-2, GL-3 and GL-6 specs are NOT in curent use.

 

[unDummy]

My favorites are Redline MT90 and Neo75/90hd.

I've used Mobil1 GL5 in several GL4 Nissan manuals with no problems(200k miles and totalled). But, switching from Mobil1 to Redline was noticeable. Switching from OEM to Mobil1 was equally noticeable. I've also run Amsoil but it wasn't long term--accident. It too is a good shifting fluid.

Most Nissan dealers around here have 75/90 and 75/85 GL4 gear oils. Valvoline/Pennzoil/Stalube/Castrol/Quakerstate/Noco/BP.....make GL4 lubes. Finding them is sometimes difficult. Most autopart/truck/marine stores can order almost anything if you have info on a product/brand. Otherwise, use the phone book and call the oil distributors in your area.

The GL4 is good for GL5 compromise didn't affect my Mobil1 application. Some say that quality synths use less EP/AW than mineral oil so that GL5 synths are safe in GL4 transmissions. Amsoil/Motul/Mobil1/RoyalPurple/OTC....sell GL5 synths for GL4 use. I'm guess that if an oil passes a certification test, the amount of AW/EP is irrelevant.

Maybe its time for VOAs on a battery of gl4/5 synth/mineral oils to see what PPM/% of whatever is there.

 

[pgtr]

Other than 1 or 2 marketed as marine oils, MT90 (&MTL) is THE only synth GL4 specific oil I'm aware of. Oh yeah, Pennzoil has a synth GL4.

StaLube offers a dino GL4 and it IS available somewhat - I bought it at Pepboys years ago but now I think you can get that GL4 thru NAPA.

Pennzoil GL4 I've never personally seen though it's known to exist in a couple of varieties. (At least you can order RL from a million places and find it locally sometimes)

Quakerstate is pretty much Pennzoil no? But you're right they too offer a conventional GL4 but nothing beyond that. Same deal - good luck finding it.

Last I checked, I don't believe either Castrol or Valvoline made a GL4 specific lubricant (and I hate going to Castrol's website!). Besides if they did, I suspect you might as well lump it in w/ Pennz/QState as not readily available.

Why do some of these guys bother putting GL4 on their sites - Can't believe they sell enough to justify it they way don't market it or market or make it available - not even mail order.

My experience w/ M1 GL5 is that it produces a slight notchiness in Japanese transmissions in comparison to a straight GL4. (note that at one point in time years ago I believe M1 claimed both GL4 and GL5 as a combo but not anymore and only recomend their oil if the manufacturer specs GL5 or motor oil).

Your point about factory fill is well taken - I suspect, given todays lack of selection, many makers themselves dump in a gl4/5 combo of some sort. Besides if they recommend straight GL4 only, where would the customers buy it at? Just a theory in my part and not to downplay RL but I sometimes wonder if the RL results most including you and myself experience isn't due in part to a less than optimal factory fill in the first place.

Interesint point about Nissan dealers. I've tried a few manufacturers websites like GM and Ford but they are notoriously bad about offering much info on consumables like the lubricants they relabel and sell. I'm not going to bother checking out any other automakers sites but I might call a few local dealers. But if it's just dino stuff - the StaLube is or 'should' be readiy available too. Thanks for the great info. I was starting to think I was the only one stuck on GL4!

PS: Gotta say that when it comes to specialty oils (and I don't think GL4 should be specialty oil but it is!) that the brands like RL and Amsoil et al distribution channels really ROCK compared to the so-called mainstream mass marketers.

 

[TooSlick]

pgtr,

Amsoil makes an 80w-90, GL-4 only synthetic gear lube - it's essentially the same stuff as their Marine Gear Lube. It's also quite a bit less expensive than their GL-4/GL-5 formulations.

Tooslick