Is MT 90 still the prefered transmission fluid

[Adrian Thompson]

Simple Q, is straight MT90 the prefered transmission fluid for an 88 manual box? Do people use it straight or mixed with something else?

Thanks

[DrewP]

Yes. Usually run it straight. It solved a hard shift into 5th when hot in my 457-14 gearbox from a 2.1L N/A car.

If the fluid has been in there a really long time or it's gummed up with something I'd flush it out with plain motor oil mixed with a little kerosene / diesel / ATF to dissolve some of the buildup before filling with the expensive Redline (that's what I did on mine, I had Shockproof Light in it before and it turned into gel in under 2 years and coated everything - see this thread).

It shifts great now.

[Crazyswede]

Jon Williams turned me onto honda manual trans lube which cheaper than redline mtl and looks suspiciously similar...seems to work just as well.

[hutch]

Yeah I would agree that it works well in high heat applications, in the cold it is certainly very different but it feels great once it is warmed up. Especially when compared with a gearbox with the stock (possibly never changed) oil inside. For a race car I would certainly recommend it but as a DD not so much as it can be a bit extreme in cold temperature in my experience.

I had heard about the Honda stuff, though in the long haul its not crazy expensive to change the transmission fluid my guess is the Honda stuff is made in the same factory but gets a different sticker on certain days so you could probably get away with it.

[Jordan]

MT-85 is ideal for daily drivers in colder temps. Mt-90 is great for higher temp and racing applications.

You can cut in MTL into mt-90 which is essentially "Mt -80" To make mt-85, or you can just buy it.

[Adrian Thompson]

Thanks for all the feedback. the car is just a toy for Rallycross, Autocross and track days, so I'm not too worried about DD ability. I plan on driving it to work occasionally for fun, but my DD comes from Gothenburg and Detroit not Trollhattan :)

I will go and look for the Honda stuff if consensus is it's basically the same.

[Luke]

I used the Honda stuff in the past, it is similar to MTL, not to MT-90. Its very free flowing and watery.
I highly recommend MT-85 for C900 street cars. Its worth the extra money.

[Adrian Thompson]

So, a new twist. Someone suggested I head over to 'Bobistheoilguy' forums where all the lube geeks hang out

I'm waiting for a moderator over there to approve my account so I can ask Q's but searching for Redline MTL similarities to Honda MTF I did find some people who had paid for oil analysis of virgin samples of each, plus virgin Amsol MTF. The Honda was done by Blackstone and the others by Oil Analyzers inc at a different time. But here are the results


o, they are not the same. It's interesting that the Honda has lots of calcium but no Magnesium, but that both the Redline and Amsol have lot;s of Magnesium and very little Calcium. What does that mean? I have no borking idea. Anyone smarter than me? Well that's simple, lot's of you are smarter than me, but does anyone know anything about oil?

[Jordan]

I know you're thinking too hard.

[Adrian Thompson]

I know you're thinking too hard.

That could be true

[Crazyswede]

those numbers are typically PPM (Parts Per Million)...so they look like a lot..but not so much.

[Geoff]

Honda MTF is better as a baby powder. Redline and Amsoil MTF are better if you have a tummy ache.