What is GM 89021806 MT Fluid? (for their Aisin 5 speeds)

[asdf]

I believe this fluid is spec'd for GM's with the Aisin 5 speed manual transmission in Colorados, Canyons and maybe a few other vehices like the new Kappa platform.

Anybody know anything about it? Like it's viscosity, GL rating etc...?

It doesn't appear to cross reference to their synchromesh fluids, synthetic MT fluid or older conventional gear lube which leaves me puzzled as to what is special about this stuff.

 

[Malaclypse]

Manual Transmission Fluid

API AI-A or GL-3 SAE 75W-90

GM P/N 89021806 (Canadian P/N 89021807)

That's what Service Information says for the 2004 model year.

 

[asdf]

I've never heard of API AI-A? Does anyone have any info on this?

To make sure that's not a typo - that's GL-3 as in three? I wasn't aware that one was still in use.

Interesting. THough 75W90 is common enough in GM's products I don't think they had anything that was GL-3 (or GL-4) and that must be why they put this p/n out.

 

[unDummy]

What, a 90-wt ??????????

Where is the thinner is better crowd?

About time they move away from MPG to longevity. Long live the thicker gear and transmission fluids.

 

[G-MAN]

quote:

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What, a 90-wt ??????????

Where is the thinner is better crowd?

About time they move away from MPG to longevity. Long live the thicker gear and transmission fluids.

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75w90 is a relatively THIN gear oil designed for friction reduction and improved MPG. 75w140 is the "old standard."

And BTW, a 90wt gear oil is roughly the equivalent viscosity of a 40 to 50 wt motor oil. Even with those transmissions that spec a 75w85 fluid you're still talking about a 30wt oil. Viscosity is only one part of the equation when it comes to protection; gear oils need good EP additive packages no matter how thick or thin the oil is.

 

[asdf]

quote:

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75w140 is the "old standard."

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It is? I've owned a decent mix of vehicles (all were MT equipped) from N. America, Europe and Asia manufactured over a 40 year spread and not once can I recall one that spec'd 75W140 for the manual transmission. Nor do I recall ever seeing it referenced in older passenger car service literature predating my ownership experience. The 'oldest' standard I've encounted goes back to the early 60s and that's MIL STD 2105 - typically a 90Wt gear lube. How far back is this 'old standard' of 75W140 from for manual transmissions?

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Back to the subject at hand - does anybody know about the API AI-A standard referenced above??? Searching this site, API.org and google yielded nothing helpfull.

Also is there anything about the GL-3 standard that would make it exclusive of substituting a GL-4 in an MT?