S2KI Honda S2000 Forums - Gearbox oil recommendation?

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I put in Amsoil when I bought the car a few months ago
First week or so was amazing, everything was so smooth and effortless, but that quickly reverted back to being notchy unless I get enough heat in the trans by driving it fairly aggressively lol. I'm in Canada.

Going to try MTF2 or Redline MTL in the spring and see how that goes.

Be careful the ~~Amway~~ Amsoil fan boys will consider this heresy. :cool:

-- Chuck

Well, I do use a lot of Amsoil. I'll plead guilty to that. Fanboy? Nope.
My experience so far is that none of these fluids we are talking about has any long term impact on the inherent notchy character of our gear boxes when they are not fully warmed up. In my opinion the issue is dealt with by developing a shifting technique that works with the car when it is still cool. I'll keep searching for the holy grail. But, I don't expect to find it. I do wish I understood better what is actually going on in the gear box that causes that "catch" or "notchy" feeling many of us experience. Is there any real reason to expect that one fluid over another could actually eliminate it? I doubt it.

Quote:

Originally Posted by jiepo (Post 24526200)

Hi, is there any explanation why the shifting changed over 1 week of using the amsoil mtf?? You wouldnt think the oil would degrade in a week? What do you think?

I have to correct my previous posting because of new insights.

Our gearbox was manufatured by Mazda, used into he RX8 Wankel and the MX5 (Miata). Mazda recommends only 75w-90 for this gearbox.
The Honda MTF is thinner, it´s a 75w-80 grade (Search the internet...)
I think it is safe to say you could use any GL4 or the new gl4/5 in 75w-80/85/90 grade in this gearbox.

I think its worth to have a look at the datasheet regarding the actuall viscosity of the oils you want to use. There are somentimes huge differences between oils, even if they all say "75w-90" on the bottle.
Here is a little list for 40°C/104°F and 100°C/212°F viscosity for ROWE, MOTUL and MOBIL1 GL4/5 gearbox oils i have made for myself out of curiosity. The differences surprised me:

Rowe Topgear 75w-80 - 37,8 - 7,50
Rowe Topgear 75w-90- 78,5-15,50
Motylgear 75w-90- 114-17,10
Motylgear 75w-85-82,6-12,60
Motylgear 75w-80-58,8-10,10
Mobil1 SHC 75w-90-102-15,10

My bet is, that the Motul 75w-90 is the worst at startup when cold, and that some -80 oils lacks a little bit of hot viscosity (Read: Protection) for my personal taste. Therefore, I will give the Rowe 75w-90 a try.
And, as stated above, adding a little bit of a dedicated additives generally works great and improves shifting feel. And dont forget, regreasing the shifter may help to.

.

Experience with hundreds of S2000s is more useful than just one.

Go to post No. 14 here. <--- that's a link. And read why.

Spoiler:

Quote:

Personally, I have had fantastic results with Honda MTF, in my car and hundreds of others.
(Billman250)

-- Chuck

That number is now in the thousands.

Anyone using anything other than Honda MTF to improve shift feel are only masking an underlying problem. It can go 30k miles in a street car, and perform as good as the day it was put in. Track use can surely cut that number more than half.

Im not saying other fluids are worse, and sure there may even be something better.

Clutch fluid, clutch adjustment, input spline rust, and driver error are the number one causes of notchy shifting.

Number of shifters re-greased to this day is still zero. Yes it will smooth things, but it is only making the true underlying problem feel less invasive. Masking the problem will result in smoothing the oil teeth off the synchros, making all gears shift worse.

Most important, increased shifting effort when cold is 100% normal.

Quote:

Originally Posted by Mr.Matchbox (Post 24577926)

I have to correct my previous posting because of new insights.

Our gearbox was manufatured by Mazda, used into he RX8 Wankel and the MX5 (Miata). Mazda recommends only 75w-90 for this gearbox.

Well this is news to me. Source?

I've spend loads of time reading about / driving s2000 and Miata and never heard this. Also the Miata transmission feels nothing like the s2000. Throws are a tad longer.

Quote:

Originally Posted by Mr.Matchbox (Post 24577926)

The reason fluid choice is so contentious may be due to different climates, say the Northeast (where Billman is) vv Arizona, and different driving styles, like a hpde driver v someone who never drives more than 20 miles at a time and doesn't exceed 5k rpm. Fluids function differently at different temps, and functions differently after different temps. One reason people like redline is it holds up better to the heat, say hot climates and the track. I run it because I wasnt as impressed with how my car shifted with what was in it (probably original fill), it was almost due for a change and redline really improved shifting in my NC miatas, including in a gearbox that had been abused by the previous owner. What you have to remember with these cars is you can use OEM fluid, and if you don't like how its behaving you try something new. In my case, redline improved the shift feel in all areas, even when cold which isn't always the case, but I didn't have fresh oem fluid in it to compare it to. For normal applications, pick the redline fluid they recommend on their site.

There's a YouTube vid with the head of spoon talking about different oils in the s2000, and he says it's more important to change the trans fluid every time you change the oil than what kind of fluid you pick.

Quote:

Originally Posted by lookstoomuch (Post 24577990)

Well this is news to me. Source?
I've spend loads of time reading about / driving s2000 and Miata and never heard this. Also the Miata transmission feels nothing like the s2000. Throws are a tad longer.

It's been discussed here before, its definitely not the same as any Mazda tranny.
https://www.s2ki.com/forums/s2000-ta...n-az6-1056948/