I got a question , what do u guys use to replace the factory fluid in both diff and tranny and where can i get it .

 

Redline MT90 (MT) and 75W90 (diff'l) SummitRacing.com

http://www.summitracing.com/parts/RED-50304/

http://www.summitracing.com/parts/RED-57904/

Two quarts each and get a ~$5 hand pump at Pep Boys.

Oh wait, you're Canadian....... please stand by for local insight....

 

I just did all my fluids...

Willwood 570 brake fluid
Redline MT90 transmission
Redline 75W90 differential
Engine oil...


Car has regained some torque down low....

 

check out scarboro mazda

 

Amsoil.

 

I'd highly suggest the Eneos 75w-90 GL5 which can be used in both the diff and tranny without any issues. It's smooth shifting!

As for where to get it? BHR has it available!

 

DON'T use GL5 in the tranny ever!

 

Why not?

 

Talk to the guys who used RP. If you WANT to replace the transmission then go ahead and use it.

 

Is it safe for the Diff?

 

As has been stated in thousands of other posts on here a great combination in Redline MTL or MT90 in the Trans and Redline 75W90 gear oil in the diff. Its a proven package, we have now done at least 100 over the years with zero failures. We keep the product in stock and its reasonably priced.

 

I have it in my diff, i HAD it in the trans but quickly swapped it out after 7 days. now i have redline shockproof heavy

 

Thanx guys , i ended up going with Amsoil Severe Gear 75w-90 in both tranny and diff. which i had easy access to thru my buddies shop.

 

i hope thats not synthetic if you put it in the diff...

 

It is actually , Synthetic extreme pressure lubricant , thats what it says on the bottle .
Why whats the difference , shouldnt it be better ?

 

Ive always been told not to use synthetic in the diff on rx8s. they have clutch plates that dont work well with synthetic lubricants. If i were you i would get that out of the ASAP. you dont want to cause harm to that wonder limited slip unit that is a part of what makes the 8 handle so well. I cant say 100%, but im pretty sure i read somewhere at work that synthetics are not recommened for use in the limited slip units specifiacally by mazda. I'll try and find it on monday. but seriously, all i've always been told the same thing about any LSD units is that "syn" is a sin.

 

Ive always been told

im pretty sure i read somewhere

i've always been told the same thing

Three strikes.

You're out.

Whoever has 'always been telling you' is ill-informed.

 

Thanx Greg , ill also look into it , i just got it done today so think i should be ok for couple of days . The reason why i went with it was that the Asmoil.com site had all the oil specs what to put it where , so i just went with it , and also i think read somewhere here guys using the same oil in their diff i am just not sure if it was synthetic or not .

 

thats fair. we'll see if i can find that at work about not using synthetic in the diff. Im all for it in the transmission however the LSD units are pretty sensetive to what fluid is used in them. I know at toyota if you didnt use a special LSD gear oil with a friction modifier the thing would be toast inside of a month. But like i said, fair enough. I haven't given any solid proof or anything. I'll see what i can dig up. there has to be a reason that everyone that uses redline products in their 8s use mt90 in the tranny, but redline 75w90 (which is non synthetic) in the diff. I'll get to the bottom of this.

and mar10. i like amsoil products. we put it in a friends cbr1000 and it was like night and day. They seem to make really great products. I was thinking about using that in my tranny this year, but i was bored at work today so i decided to change it for the normal 75w90 non syn bulk crap we had in stock. after 5 track events, the year old redline mt90 was definitly tired. even the crappy bulk 75w90 made the tranny feel better. haha.

 

If you read the label of any Redline Shockproof gear oil it clearly states NOT RECOMMENDED IN SYNCROMESH type transmissions. If you gear oil is thick and pink when you come on for a broken gear box, you will not receive warranty for it (at least here in Canada). For the Canadians please DO NOT USE any type fo Shockproof gear oil in your transmissions or diffs.

 

Greg, I believe that the Non Slip synthetics are not for use in clutch pack style limited slip diffs. The regular Redline 75W90 is fine, its the 75W90NS that is bad for you clutch packs.

 

Don't worry. I run Amsoil Synthetic Manual Transmission and Transaxle Gear Lube 75W-90 GL4 in the tranny and Severe Gear 75W-90 GL5 in the differential. If the stuff you have in the tranny is GL5 get it out and put GL4 in.

 

I am not sure if its a GL4 or GL5 doesnt say on the bottle , all it says Severe Gear SAE 75W90 synthetic extreme pressure lubricant and i put it in both tranny and diff .
Thats what it said on the Amsoil site to put in , i assumed that they know what they are talking about .

 

I believe it's a GL5 which was why I specifically used the different tranny fluid. Severe Gear I only used in the differential. I checked on my product info and it is a GL5.

 

Nosferatu , yea you are right it is the GL5 stuff , now what is the difference between GL4 and GL5 , what does that mean ?