Hi, I just ordered some redline fluids from a local parts store...the bottle for the transmission reads:

75W90NS

and the differential reads

75W90

I told the parts guy I wanted MT-90 for the transmission...but nowhere on the tranny bottle does it say MT-90...and neither of the bottles (tranny/diff) look like the photos of the bottles here @ finishline:

http://www.finishlineperformance.com/images/74.jpg

http://www.finishlineperformance.com/images/81.jpg

Did they give me the wrong bottles? Also, finishline says it says GL-4 for the tranny...on this bottle it says GL-5...

 

I just went to redlines website, and these are what was given to me:

http://www.redlineoil.com/products_g...sp?subcatID=20

and

http://www.redlineoil.com/products_g...60&subcatID=20



Also on the website....is what finishline sells:

http://www.redlineoil.com/products_g...57&subcatID=18
http://www.redlineoil.com/products_g...57&subcatID=18

I'm guessing the parts store gave me the wrong kind???

 

then you got the wrong bottle from the local parts store, the MT90 labels CLEARLY, 'MT-90'

though 75W90NS WILL work for the transmission, but you might as well go for what you want in the first place and exchange it for MT-90 instead.

 

Alright, would it hurt anything if I use it? Chances are I will just take it back.

 

using 75W90NS wouldn't hurt your transmission.

 

Alright, I just heard somewhere on the forum that GL-5 has sulphur in it....and is bad for the brass components in the gear box/tranny...and GL-4 doesnt.

 

The 75W90NS is fine for the tranny but if you have the limited slip differential, DON't use it in the differential. The NS lacks certain additives that the LSD requires. The straight 75W90 is OK for the differential. Now go get gooey.

 

GL5 is FINE in the transmission (see Owner Manual)

 

that only applies to clutch pack LSD's, which the RX-8 is not

I run Redline MTL in my tranny, which is a modified 75W80

Redline MT-90 is a thicker 75W90 version of MTL per their literature

 

I'm a tech n00b, but I'd heard that it's very difficult/impossible to change your own tranny fluid out without using a pressure system to flush it. Otherwise you'll only be changing a little at a time since it doesn't all drain out completely.

Soo, I need to find some shop to do this for me?

 

^nope, i think you're talking about an AUTOMATIC TRANSMISSION flush, in which case, yes, you'll need professional equipment to do the flush

in the 8's manual transmission, it is simply drain oil, refill with new oil, and done.

 

What ZoomZoomH said. Read the DIY thread at the link below for everything you need to know about changing the tranny and differential fluids, and then some.
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-transmission-differential-fluid-replacement-35115/

 

I would recommend being well out of the way when you pull the Drain plug from the Transmission. It comes out EXTREMLY fast, and if you just drove up it is also pretty damn hot.

When I pulled the drain plug it coated my entire left arm in hot gear oil! One more thing to note is the Gear oil doesn't smell very pretty.

 

^and to avoid hot gear oil from splashing said left arm, DO NOT fully remove the fill plug, loosen it, but leave in the threads so that the gear oil will drain out slower from the drain plug hole

 

What I do is loosen the plug, then turn it by hand. If you keep pressure against tranny, you will feel when the threads have finally worked all the way disengaged and you'll feel a little "click" At that point the pressure of your hand is all that is holding the plug in place and you can pull it away very quickly to avoid getting oiled. Just plan the maneuver in advance so you don't bang your hand on something else. I like the idea of having the oil gush out. I hope it flushes a little more crud off the bottom of the case but it probably doesn't matter at all