I dont see any polls for what kinda gear oil everyone prefers for Transmission and Differential. So here it is. I know a lot of you guys argue back and forth on whats better so now we will find out! Im not referring to whats best for race prep cars, just the daily driver/sprited driving community!

 

DO NOT use royal purple maxgear in you're tranny.

I switched from OEM tranny fluid to RP maxgear and I started getting 2nd gear grind. I switched to Red Line MT90 and the grind was gone after 2days.

 

i'm sticking with OEM after needing a transmission replacement from maxgear...

 

haha im in the SAME boat as both of you... i guess we will see.....

 

royal purple is that bad?? i used it and it made my car that was grinding shift better?... maybe thats why it finally died.. lol

 

RP has worked perfectly fine for me for more than 50K and more than 1K of track miles.

 

I'm using RP Maxgear. I started off putting the 75W90 in the tranny and rear end.

I started having problems putting it in gear especially after a run in autocross. I switched to RP 85W140 and the feel is perfect. It even goes into reverse now when its cold outside on the first try. I still have the 75W90 in the differential though. I'm thinking about maybe getting the KAAZ gear oil or replacing it with something thicker.

When I was using the lighter RP it never would grind, just would not go into gear. It did make a whiiirr noise though. Maybe no one should put 75W90 in their transmission.

 

I believe Red Line is GL-4, which is better for transmissions that contain brass parts. My first fluid change was to Royal Purple. Would make a noise when shifting to 5th gear. Changed to Red Line, and the noise went away after a few days.

 

I used RP on my first transmission.
Now using Redline with the new transmission.

You decide...

 

redline 75w140ns

 

lol looks like i have some rp tranny fluid for sale! anyone?? ill still use in my differential though

 

ok which to get redline 75 90 or 75 140 im going to order some right now if you guys can tell me which to get

 

OEM gave me the best shift quality and I've tried both Royal Purple and Redline. If I could find the OEM again I'd put that in.

 

Shell Transaxle Oil, 75w90.
Not very commercial but is used as the differential lube in the ferrari challenge.
Put it both in my shift and my differential while mounting the final gear.
It really changes the shift feeling and doesn't soften after 40minutes of continous track drive.
I really suggest it!

 

too late i just ordered redline 75W140NS GL-5

 

wrong choice

 

ok guys. i have a AT and i need to change the fluid. and im thinking about going with Red Line.. but what weight and that stuff should i get? and how much does the AT take?

 

I use redline

 

I drive an M/T so I don't know what specs are recommended BUT the info is in the back of your owner's manual. Look under fluids in the index.
If you don't have the owner's manula, register on Mazdausa's website as an owner and you can download a PDF version.

 

How?....

 

What about BG syncroshift 2?

 

I'm using Redline for both. 75w90 weight in the tranny.

 

I really want to try this: http://www.fcsdchemicalsandlubricant...ission%20Fluid

The 6 speed Miata guys seem to really like it, and as we all know our transmission is pretty similar to the 6 speed NB tranny.

 

I got some Amsoil 75w-90 GL-4, going to try to have it done this weekend. Probably gonna have them do a BG flush to get out the Maxgear. My 2nd wasn't great before, that's why I switched to Royal Purple, but then 2nd got worse and other gears started shifting bad at times.

I'll let you know how it goes.

 

You need GL-4 not GL-5.

The techs at Red Line said MT-90 for the tranny and 75w90 for the diff.