Honda MTF

Eric wrote in news: snipped-for-privacy@spam.now:

Gear oils are graded using a different system than engine oils, so the numbers are not correlative. A 20w weight engine oil has about the same relative viscosity as a GL70w trans oil.

Honda MTL pours a lot like a straight 30-weight engine oil at room temperature, and Honda originally specified 10W-30 motor oil before sulphur-phosphorus and zinc were removed, so my guess it's still equivalent to a 10W-30 engine oil.

Might be Exxon Mobil. This stuff may be it:

Unless you're an insider, you'll never know for sure. Just like you'd never know that Canadian-market Acura MDX seats are made by Faurecia and Civic interior trim is made by Kumi Canada unless I told you so.

Consult your friendly local tribologist. Don't know one? Neither do I.

Considering how cheap the stuff is compared to what else you spend on your car every year, I just buy it from the dealer.

There are a number of anti-wear additives, not just zinc dithiophosphate.

Thanks for the info!

Eric

Unless it comes in a lighter grade, then this product is not a likely candidate as putting 80w-90 in a Honda manual tranny will kill it.

Eric

That's sounds a lot like you don't understand gear oil weight rating.

What weight would you recommend?

Eric wrote in news: snipped-for-privacy@spam.now:

I read that gear oil numbers are not equivalent to engine oil numbers. That stuff may be the same viscosity as 10W-30 engine oil.

I'm not sure. 90W hypoid oil (that nasty sulfurous-smelling stuff) is a lot heavier than any motor oil. Beyond that, I don't know.

Mike

"Michael Pardee" wrote in news: snipped-for-privacy@sedona.net:

I don't think you can compare EP (Extreme Pressure) oils with ordinary oils.

Doin' some diggin' here...

Gear oil numbers ARE different. From the Lotus link: "75W90 gear oil has the same weight and viscosity properties as 5W30 motor oil".

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Who needs to save a few bucks? It doesn't take five quarts does it? For the difference a quart or two might cost, at least you'll know that the Honda stuff has all the best additives that a Honda tranny needs. If we can judge by the (terrible) results people get when they try using 'alternative' tranny fluids in their Honda automatics, it's just NOT WORTH IT TO CHEAT. Cut back on coffee, spend the difference on your tranny MTF. :-)

You were probably going to substitute something that was even more expensive, no?

'Curly'

and from the Greer Racing link, "engine oil and gear oil have their own specific viscosity rating system. As such, the viscosity of 75-weight gear oil is equivalent to 10-15-weight engine oil."

Huh. Could be just working with the smelly stuff made me think it was thick and gooey. All oil really gets everywhere if you let it, and the awkward angles for adding gear lube make it messy.

I did find this link for how motor oil viscosity is measured, for the curious

so far nothing on how EP oils are measured. (The Lotus Elan site reminded me of my youth when I had a Lotus Europa. Did you see that improvised tool picture?)

Mike

For what it's worth, I have 10 years of professional experience as an ASE certified tech. Six of those years were spent working in an independent Honda shop, where among other things, I rebuilt engines and manual transmissions. I have personally rebuilt Honda transmissions that had been ruined due to the fact that they had the heavy 80w-90 gear oil in it. If I remember correctly, one of them had the differential fail. This was not a typical failure and it was attributed to the wrong oil installed in the transmission. This was over 9 years ago and I don't recall whether or not Honda MTF was available at that time. The owner of the shop has a degree in mechanical engineering. Under his guidance, and Honda's recommendations at that time, the shop used 10w-40 oil for manual transmissions. I believe that they are now using a synthetic gear oil though I don't recall the specifics right now.

Eric

On 2005-03-25 snipped-for-privacy@spam.now said: >Newsgroups: alt.autos.honda >Steve Bigelow wrote: >> >>

Tom Willmon near Mountainair, (mid) New Mexico, USA

Net-Tamer V 1.12.0 - Registered

It still sounds like you don't understand gear oil weight ratings. You DO realize they are measured on a different scale, right?

80 gear oil is about 8 to 11 cSt. 90 gear oil starts at 14 cSt.

10 motor oil is about 4 to 6 cSt.

40 motor oil is about 14-17 cSt.

So, 80w-90 gear oil is *slightly* heavier when cold that 10w-40 motor oil. Slightly. A better choice would be 75w-80, which is bang on a 10w-30 motor oil, but has the anti-shear additives that motor oil doesn't have, but gear oils need.