Stratocaster

We had a customer who had put LE607 in the transmission So we told him that it was for the diff and that he should have it drained and filled with Honda MFT. He said that he had autox a few times and the fist time, on the first run "It would not shift well and was very tight" But after that it ran great for the rest of the day (5 more runs) and at the track.

Anyone have any ideas of what the impact to doing this might be? Or what should be done other then changing the fluid with the right stuff, I mean should it be flushed? If so How?

And, what would be the impact to using a thicker fluid (thiner the LE607) too? MFT is about a SAE30 if I remember correctly.

xviper

I can't remember if LE is harmful to yellow metals. Road Rage might know. If it is, the syncros could be on their way out.
Putting LE into the tranny would be akin to putting in molassus. Until it warms up, it's like churning butter. To get it all out would require a flush with some kind of manual transmission flushing agent. Look to an autoparts store for something appropriate and follow the directions carefully. Then, I would put in the correct tranny fluid, run it for a couple of days and then while it's still hot, drain it and put some more fresh MTF in.

ps. It kinda boggles the mind that people think manual tranny fluid and rear diff fluid are interchangeable.

Ludedude

In some cars, like my Miata, they are.

It all depends on what the material used in the syncros is. I can pour GL-5 75w-90 diff fluid in my Miata transmission and have no ill-effects whatsoever. The manual even says so

xviper

Point taken.

cdelena

It is too late to worry about impact.. it is done, big or little. I would drain it, refill with MTF, drive for 5 miles, and change again with MTF.

Stratocaster

Agreed. Whatever was going to happen has happened. This was a thread to talk about what that might be. It was also to talk about a thicker OIL other then MTF and what +/- that could come from it. The owner that did this, did said that the trany worked great aafter it warmed up. So I posted the question what if the oil was thinker? It seams to be common that when MFT ages, shifting get notchy. Maybe if the oil was thinker (Honda states that you can use 10w30 in a pinch), so what would the impact to that be?

cdelena

I use RedLine MT90 in the summer heat sometimes which is not as heavy as LE607, but quite a bit heavier than MTF. It works very well until very cold days where the box gets balky. I don't think the weight is near a big an issue as the EP additives that can pit the yellow metals.

Squeezer

agreed, most manuals can use 75w-90 gear oil fine, unfortunately the s2k has brass synchros which most 75w-90's will destroy. use only honda mtf in the transmission.

Ludedude

Correct. It's the additives used to meet the GL-5 spec that are harmful to the yellow metals (brass) in the transmission of the S2000. The weight is irrelevant from that standpoint.

Personally I use MT-90 year round in the S and am doing the same thing in the Miata. Of course my climate is more extreme than most. It's been in triple digits for 3 days in a row already.

Road Rage

It was very poor judgment for this person to use LE-607 in the tranny.

I already posted a detailed analysis of the additives in LE 607, which included I believe the ONLY Web description of the Almasol additive. If Search is acting up again, here is the skinny:

LE uses a proprietary EP additive, Almasol, in LE 607. This is one reason it is such a special product - LE has its own division which develops additives, unlike nearly every other oil company (including the Biggies), who buy them from specilaists like Lubrizol. As I recall, Almasol is made from compounds of aluminum and magnesium silicates. It also has sulfur - I do not think they are recative sulfurs, but they are sulfurs.

Reactive sulfurs can damage yellow metals very quickly - non-reactive sulfurs may or may not, depending on may factors.

The important thing is to get that 607 out of there!

Then, the next thing to do is to flush out as much of the 607 as possible.

I think 3 cycles* of drain, refill, and drive until tranny is hot will do as much as can be done. I would recommend a quality 10w30 ENGINE OIL for this.

Why?

1) It is cheaper than MTF
2) It has high detergency

After the last cycle, let the tranny drain completely, then refill with MTF. I would not use GMS FM or any other slick aftermarket part, in case there is a chance of salvaging some warranty coverage if things go badly - there is no info ont eh age of the car.

*Inspect a quart of the drained lube in a clear container - look for any residual pink - LE607 is dark purple, so any residue would show up as pinkish. Continue to flush until the fluid is free of any pinkish hue.

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The "weight" (viscosity is a better term) of the tranny fluid has been debated many times before. My current opinion is that the S2000 tranny is all about "feel", and one should use the tranny lube cl;osest to MTF's vis that procides the shift quality you seek. GMS FM is a bit "thinner" than fresh MTF, but about the same as MTF after Honda's product has sheared down in 15k miles or so. But since GMS FM has a high film strength (it is semi-synthetic), I do not worry about premature wear at all.

MTF and GMS FM are in the 70w/75w/80w range (as is Red Line's MTL). MT-90 is closer to a 75w90. The more viscous RL will not necessarily provide any benefits, since flow rate is showing up in engine and tranny alike as a critical factor. The S2000's tranny uses a trochoidal pump to keep the tranny lube flowing under all conditions (just as in the NSX), and the pump is designed for the vis of MTF or 10w30 engine oil. I doubt whether MT-90 would hurt anything, but neither do I think it is protecting "better".

Again, to me it is all about the shift feel and quality, as long as the fluid's vis is close to mTF (NEO, for example, is way too thin) - experience here and on the 6MT in the 3rd Gen Acura TL's suggests that those who have swapped for GMS FM have been very happy - with reduced 1-2 crunch in the S2000, and much less notchiness in the TL.