GL4 MT synthetic transmission fluid for Forte Coupe 6 speed. Can i use GL5? + other questions.

Job

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Dude, I've seen all of that, no need to repeat it again and again.
This product obviously is still marketed primarily as a 'GL-5 LSD
gear oil intended for rear differentials'.
If you made your choice before asking here just use it. However
you won't convince me it's a wise choice for longitudinal manual
transmission applications like yours.
.
Dude, not trying to convince anyone of anything. I present the facts, if somone wants to learn something new or not, it‘s up to them. I wasn’t even sure it was new info.
If Eneos says compatible for synchromesh, it is compatible. If they say proprietary tech that enables easy and smooth shifting at low temps, they have tested that. They explain more somewhere, base oil needs less additive. Not that interested in the whys to spend time on it. Only need to see a highly regarded company says in writing compatible. Then it’s done.
 
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Dude, not trying to convince anyone of anything. I present the facts, if somone wants to learn something new or not, it‘s up to them. I wasn’t even sure it was new info.

So you did ask a question just to teach other people? That's interesting.
I'd say you expected a confirmation for your choice and didn't get it.

.
 

Job

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So you did ask a question just to teach other people? That's interesting.
I'd say you expected a confirmation for your choice and didn't get it.

.
You guess wrong, making things up. I don’t know why one side of the bottle is read, but the other side is not. Not my issue. I know the Eneos gear oil works nicely, and it is safe to use with synchromesh, no more guessing.
 

MolaKule

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The back of the bottle says compatible with synchromesh. This takes away the yellow metal worries. Then it says our proprietary tech enables easy shifting. That’s my end of specificity needs.
Whatever company, if they are reputable and say compatible with synchromesh, and GL4 or 5, on my vehicle it is OK. What bothered me was Valvoline and others putting GL4 and for non sychronized on the bottles. So if Fly By Night Oil says GL4, but nothing else, it does meet GL4, but is it compatible with synchromesh? They only have to say GL4.
I just thought people might be interested in a GL5 that also works for manual transmissions. It definitely shifts like a champ now. But I did make some repairs to poor work on the shift lever area. The shift lever seat and nylon ball on the shift lever end were gone, not there. $8 worth of oe parts and they are back in again. So easy to do too.
What Valvoline product are your referring to, the Pennzoil synchromesh? if so it is too thin for an application requiring a 75W90.

An LSD friction modifier for a hypoid differential requiring a GL-5 EP protection fluid doesn't have the same chemistry as an MTF for a synchromesh.

I sincerely hope you're here to learn because that is what BITOG is all about.
 
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Job

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What Valvoline product are your referring to, the Pennzoil synchromesh? if so it is too thin for an application requiring a 75W90.

An LSD friction modifier for a hypoid differential requiring a GL-5 EP protection fluid doesn't have the same chemistry as an MTF for a synchromesh.

I sincerely hope you're here to learn because that is what BITOG is all about.
The Valvoline brand 75w-90 synthetic gl5/gl4 in the squeeze bottle, plus Napa has the same disclosure on some also, maybe others. GL4 and not for synchromesh. It doesn’t mean all are non, it means they disclose more, which was my main point. What if they do not disclose? GL4 can remain as Valvoline testifies to.
The Eneos is GL5 with lsd and is for synchromesh. Disclosure about compatibility in writing on the bottle is very strong.
Its like challenging the SP rating in every bottle of oil on the shelf. No, I believe them if they are a reputable company.
So you are saying from the link you know more than Eneos about their product? First take what they say, then try to find out why, would be learning. This what happened about this oil is the opposite of learning. People won’t even read things opposing their own preconceived notions. They read one part they like, and ignore the part they don’t like. That is not learning. I bet somone here said I am stating false information, didn’t they. No I did not.
I wouldn’t be so fast to promote this site as a learning site when it becomes a war of wills site. A lot of misinformation accepted here, and it is fairly recent. The strong wills prevail, just like in nature.
Now if you make a scientific claim that Eneos tech and their claim is faulty, thats what I want to see. I am sure they will put a new label on immediately?
 

MolaKule

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The Valvoline brand 75w-90 synthetic gl5/gl4 in the squeeze bottle, plus Napa has the same disclosure on some also, maybe others. GL4 and not for synchromesh. It doesn’t mean all are non, it means they disclose more, which was my main point. What if they do not disclose? GL4 can remain as Valvoline testifies to.
i have no idea what this is supposed to convey.
The Eneos is GL5 with lsd and is for synchromesh. Disclosure about compatibility in writing on the bottle is very strong.
Its like challenging the SP rating in every bottle of oil on the shelf. No, I believe them if they are a reputable company.
The second sentence is a false analogy. In the first sentence you are accepting a claim without knowing anything about its chemistry.
So you are saying from the link you know more than Eneos about their product? First take what they say, then try to find out why, would be learning. This what happened about this oil is the opposite of learning. People won’t even read things opposing their own preconceived notions. They read one part they like, and ignore the part they don’t like. That is not learning. I bet somone here said I am stating false information, didn’t they. No I did not.
So it appears you're here to argue rather than to learn and to discuss the actual chemistry of gear lubricants?
I wouldn’t be so fast to promote this site as a learning site when it becomes a war of wills site. A lot of misinformation accepted here, and it is fairly recent. The strong wills prevail, just like in nature.
There are assertions and claims that can be made about any product and then there are facts. This site has always been about learning and discussing lubricants.
Now if you make a scientific claim that Eneos tech and their claim is faulty, thats what I want to see. I am sure they will put a new label on immediately?
I know from developing gear lubricants that the chemistry used for LSD friction modifiers in GL-5 Hypoid differential lubricants are entirely different than the friction modifiers used in MTF's.
 
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MolaKule

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I've been thinking since another user posted and informed me on, that i might of bought the wrong mt fluid for the kia. It is Full Synthetic Valvoline 75W90 gear oil but i believe it is GL5, and not GL4, and to be honest I know very little about MT fluids - but i'm learning fast!.
The plan was to change the current fluid out with the Valvoline 75W90 run for some time, then drain and refill with Amsoil Manual Transmission & Transaxle Gear Lube 75W-90. But if the Valvoline is GL5, (is it backwards compatible with GL4?) or should i skip the pre change, and just go right to Amsoil GL4 Synthetic MT fluid:

Backstory is i called the dealer looking for OEM 75W90 fluid, and they told me they dont sell it by the qt, they only have a 55 gal drum type deal, and to go to autostore and pick up any 75W90 and it will be good to go so i did that not understanding anything regarding GL4/GL5, or anything else about the MT fluid.. Can any one shed some light? Should i return the Valvoline, and just do one change of the MT fluid to Amsoil - then call it good? Its about 23$ a qt, but its not like im changing it out every 5-10K miles. I'd have to order it online, and have it shipped. It seems like all the kia forums highly recommend this fluid for the six speed manual transmission, but i've never personally used Amsoil before... in anything.
I am not trying to correct any issues, no pop outs, grinds, or abnormal notchy-ness, i'm just looking for optimum protection, and to have the MT feel as good as it can get it.

So my questions, is there a fluid locally that I can just pick up and use that is full synthetic and GL4 compatible?
Whats the OCI on a MT fluid? It feels pretty good currently, so im assuming its been replaced in past, with what im not sure. Kia might tell you never to change it, you know "fluid for life" type deal, but it does have drain plug with magnet, and fill port that you put in about 1.9 qts of fluid.
Stick with GL4 Amsoil Synthetic, or would another GL4 synthetic 75W90 work from auto store?

Thanks for all your feedback and suggestions - it never goes unnoticed, i know as one member said im "all over the map" and there is a little truth to that. I try to stay on track, think straight and logical, but sometimes my OCD kicks in to the max, and i just cant lol, and what seems insane to some of you, (like to give the mt a change of fluid before putting in the good fluid thus in turn changing it twice) and things like that. I am working on it.... honestly.. :) Thanks!. 🙏
If your vehicle requires a 75W90 MTF, then the Amsoil MTG or the Redline MTL-90 will probably take you to 40k miles.

Now bear in mind, Manual Transmissions do have a tendency to mechanically shear the fluid to a lower viscosity over time.
 

Job

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i have no idea what this is supposed to convey.

The second sentence is a false analogy. In the first sentence you are accepting a claim without knowing anything about its chemistry.

So it appears you're here to argue rather than to learn and to discuss the actual chemistry of gear lubricants?

There are assertions and claims that can be made about any product and then there are facts. This site has always been about learning and discussing lubricants.

I know from developing gear lubricants that the chemistry used for LSD friction modifiers in GL-5 Hypoid differential lubricants are entirely different than the friction modifiers used in MTF's.
The Eneos oil is GL5 LSD, compatible with synchromesh, and enables smooth and easy shifting at low temps. If I read my first post I would say interesting, lets find out more. Learning means looking at new ideas.
No, I am not here to argue. Why are you talking about me at all? That’s not about the oil. I merely repeat what is on the bottle of a very reputable and large company. All I heard back from anyone is I know better than the bottle says. You think Eneos doesn’t have people who develop gear lubricants and know the chemistry? Learning is about exploring new ideas others have.
 

MolaKule

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...You think Eneos doesn’t have people who develop gear lubricants and know the chemistry? Learning is about exploring new ideas others have.
Ok..........................

But here is where I stand on the matter:

I reject the notion that a GL-5 with an LSD friction modifier can claim to be, at the same time, a synchromesh MTF because the chemistry of a GL-5 with an LSD friction modifier is totally different from the chemistry of an MTF; that is a scientific fact, contrary to manufacturer's claims not withstanding.

A GL-5 gear lubricant with an LSD friction modifier has its applications for highly loaded and mainly Hypoid gear designs, especially for flat or cone limited-slip clutches in automotive differentials.

Now, to support your claims, send a sample of the Eneos lube to: Savant Labs, 4800 James Savage Rd, Midland, MI 48642, and then post your detailed analysis results here on BITOG with a commentary on each component and then tell us why you still believe the Eneos claims.
 
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Ok..........................

But here is where I stand on the matter:

I reject the notion that a GL-5 with an LSD friction modifier can claim to be, at the same time, a synchromesh MTF because the chemistry of a GL-5 with an LSD friction modifier is totally different from the chemistry of an MTF; that is a scientific fact, contrary to manufacturer's claims not withstanding.

A GL-5 gear lubricant with an LSD friction modifier has its applications for highly loaded and mainly Hypoid gear designs, especially for flat or cone limited-slip clutches in automotive differentials.

Now, to support your claims, send a sample of the Eneos lube to: Savant Labs, 4800 James Savage Rd, Midland, MI 48642, and then post your detailed analysis results here on BITOG with a commentary on each component and then tell us why you still believe the Eneos claims.
Here's my take: it sounds like you can use it if your manual transmission requires a GL-5. Which most don't. But using an oil designed for limited slip differentials doesn't sound right. I know Redline says not to use their 75w-90 with LSD additives in a transmission.
 

Job

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Ok..........................

But here is where I stand on the matter:

I reject the notion that a GL-5 with an LSD friction modifier can claim to be, at the same time, a synchromesh MTF because the chemistry of a GL-5 with an LSD friction modifier is totally different from the chemistry of an MTF; that is a scientific fact, contrary to manufacturer's claims not withstanding.

A GL-5 gear lubricant with an LSD friction modifier has its applications for highly loaded and mainly Hypoid gear designs, especially for flat or cone limited-slip clutches in automotive differentials.

Now, to support your claims, send a sample of the Eneos lube to: Savant Labs, 4800 James Savage Rd, Midland, MI 48642, and then post your detailed analysis results here on BITOG with a commentary on each component and then tell us why you still believe the Eneos claims.
Sorry, it’s not my claim. I think you realize the claim is from Eneos, they have it on the bottle. I go by what they say. I don’t need to reverify what’s already been verified on the bottle. Looks like they made something new that overcomes old ideas. Japanese companies tend to do that, make what was thought not possible, possible. You have the interest to pursue, I don’t. You are the expert, as witnessed by the home page. Way over my head.
 

MolaKule

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Sorry, it’s not my claim. I think you realize the claim is from Eneos, they have it on the bottle. I go by what they say. I don’t need to reverify what’s already been verified on the bottle. Looks like they made something new that overcomes old ideas. Japanese companies tend to do that, make what was thought not possible, possible. You have the interest to pursue, I don’t. You are the expert, as witnessed by the home page. Way over my head.
You introduced Eneos into the discussion so believe whatever claims you may. Since you asserted the claims are valid, I thought you might want to pursue it with a Professional Lab to prove your case.
 
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