So Im getting ready to order my fluids from Amsoil, but i want to make sure i get the right amount of course, so for my diff SEVERE GEAR 75W-110 Synthetic 2 Quarts?
and for the tranny Synthetic Synchromesh Transmission Fluid (5W-30) 2 quarts as well right?

 

I believe rear diff is 1 quart and transmission is 2 quarts, I could be wrong. I just ordered these from amsoil as well, but got 2 for rear diff and 3 for transmission to have some extra on hand!

 

I changed mine trans and diff oil like 2 months ago and I ordered 2 quarts of trans oil and 1 quart of diff from amsoil. If you dont spill any oil while filling it than it would be enough with a little oil leftover.

 

You are correct.

 

trans 2

diff 1

 

iirc trans takes 1.6qt and the diff takes 1

 

trans takes 1.7 quarts and diff takes 0.7 quart. Do not overfill or you will be sorry...

 

Since when I look it up on Google, this page is the first result so I'll put in the official specifications.

Per Honda Factory Service Manual:
The Manual Transmission takes 1.48L or 1.58qt of fluid for a fluid change. If performing a full overhaul, it needs 1.62L or 1.71qt.
The torque spec for the fill (upper) gear box bolt is 44Nm, 4.5kgfm, or 33lbft. The lower bolt is 39Nm, 4.0 kgfm, or 29lbft.
Honda recommends Honda MTF oil.

The differential / LSD requires 0.74L or 0.78qt at fluid change. If full overhaul, 0.77L or 0.81qt .
The torque spec for the differential bolts are both 46Nm, 4.7kgfm, or 34lbft.
Honda recommends Fluid the following; Hypoid Gear Oil, GL5 or GL6, Viscosity SAE90.

 

I'm not sure if single-weight GL5 90W Hypoid oil is still available (maybe in Marine applications?). Isn't GL6 an obsolete specification?

https://bobistheoilguy.com/forums/th...vs-gl-5.58746/

I believe that GL5-rated 75W-90 or 75W-140 is fine.

 

I was listing the Honda Factory Service Manual recommendation to be completely unbiased as there will always be the "Pure OEM" originalists out there.

My biased opinion, I believe there were changes to the way viscosity is measured since the initial release of the S2000. A 75W-90 weight oil is more similar to a 75W-110 oil in modern oil standard. If someone could look up the name/date the standard was changed (like how the method of how horsepower was measured changed) that would be valuable information. When my car was used as a daily/autocross car, I would use 75W-110 (or a 1:1 mixture of 75W-90:75W-140). Now I run 75W-140 in my rear differential, but my use-case is different since my S2000 is used 95% track/autocross only. For a street only car, I still think 75W-90 is fine.