What exactly do I buy to replace the old fluid? I see ATF, MTF, Gear oil, ect ect and im not sure what exactly I need.

 

You could use Search Brand Tranny and Differential Fluid.

Seriously, you would have to tell everyone if you have an auto tranny or manual before anyone could answer your question. If you checked the FAQ at the top of the page, you could get an appropriate answer.

 

Manual, and I did look in the FAQ and did not find it, can you tell me watch section it is in?

 

use Royal Purple 75w-90 in the rear diff and u can use the same in the trans or use Neo in the trans...but I would just stick with Royal Purple...if your car has a Limited slip differential RP already has the additive in it.

http://www.rpmoil.com/index.php?main...products_id=71

http://www.neosyntheticoil.com/ if you are interested

 

I use Redline MT-90 in the tranny and love it. I forget the diff fluid, but its the redline diff fluid in the appropriate weight.

 

I was thinking of useing RP max gear(75w90) for the rear, and syncromax for the tranny, but if i can just use the max gear in the tranny also I think ill do that.

 

Exactly what you need is the shop manual link in the FAQ:
https://www.rx7club.com/showthread.p...18#post5131218

 

I used Redline 75w90 Gear Oil for the LSD. If you don't have an LSD, just use MT90 in there as well.

 

MT90 ftw in the tranny.

 

The weights you need are covered in the FAQ, the owner's manual, FSM (I assume), Haynes manual, etc. The tranny oil must be safe for synchros (most GL-5's aren't, most GL-4's are) and the differential oil must have an LSD additive if you have an LSD. Most of the time you have to buy the additive seperately.
ATF = automatic transmission fluid. If you have an automatic transmission, get this instead of the transmission fluids people are telling you to get. Check the FAQ/etc. first to make sure you get ther right kind.
MTF = manual transmission fluid. For the tranny.
Gear oil = for the differential.

Redline, Royal Purple and Neo are the most popular and are great brands. I like RP myself all around but I think the other 2 are still excellent.
I prefer Royal Purple or Neo in the tranny b/c they reduce grinding and shifting is still "instant" IMO. Redline also allows fast shifts; dunno if it is faster. Redline doesn't reduce grinding.
Mobil 1 is also good for protection, but it won't allow fast shifts and I hear it won't hold up to race conditions.

Racing Beat has a good price on Royal Purple, or you can go to Royal Purple's website if RB doesn't carry a particular oil. It's also at a lot of Pep Boys. I know Mazdatrix carries Neo, and Redline is at a lot of stores. Mobil 1 is everywhere. RP, Neo and Redline all have versions that are synchro safe and that don't require an LSD additive. Haven't checked Mobil 1. For Royal Purple you use Synchromax in the tranny and Max Gear in the diff. These other guys have told you which Redline products to get for each. I believe the Mazdatrix site says which Neo goes where, or maybe it's the same stuff in both.

 

this has been discussed lots on this forum.

Redline MT90 in the tranny seems to be a popular choice, however i don't think it is the greatest for clutch-type limited slip diffs. it won't damage it but you may not get proper lock-up. Redline has another fluid that is for LSDs, and i'm sure that is fine.

a good alternative that will work in both the tranny and diff that seems to work fine for me is Lucas Oils full synthetic tranny/diff oil. i use it in both tranny and LSD and it is working good for me...

please note that for viscous-type LSDs you don't actually need any additives in the gear oil, use whatever you want. the viscous fluid is in a separate sealed unit within the diff...