What about the stuff you can get from mazda dealerships?

 

Yes, because when you ask how much oil the transmission takes, and you don't specify the vehicle, then it makes a whole lot of difference. If you don't understand this, then maybe you shouldn't work on your car without adult supervision.

Here are links to sites that host online manuals for RX-7's.
http://www.iluvmyrx7.com/
http://fc3s.org/

If you listed your car as a 90 GTU RX-7 on a Mustang forum, and then asked how much oil the transmission takes, you would probably get a bunch of answers much less civilized than what I am typing now.

 

I heard that Mobil 1 Syn was bad for your tranny...I need to look for that thread.

BRB

 

I changed it to one of my rx7s just for you ..

 

Stupify,
just incase you need to tip your decision scales over,
Use REDLINE,
I have 88 TII, and know at least 2 other people that own an identical car. We all use REDLINE. The results are absolutely the same. The first thing you will notice, metal portion of your gear shifter handle will be much cooler due to cooler operation.

My TII uses aproximately 2 - 2.5 quarts

 

How about mixing different types of gear oil? Like 2/3 Redline and a 1/3 of GM Syncromesh,Lucas, Neo or some other gear oil?

 

LOL, it doesn't matter just as long as you mention which car you are referencing in your post.

You can list more than one car in your profile if you like, just as long as the names are short. Also, you can put them in your signature. See my profile and signature for examples of both. Note that you still need to specify which car you are referring to in your post if it is not obvious to the reader.

 

You could, but why?

 

How is Neo?

 

I guess I'll have to go with redline...if this stuff really ate transmission's I doubt they would still have a company by now...

 

I used NEO in my 88 GXL for ~40K miles, no problems. Car died at 249K from a Apex Seal Failure. Tranny was fine

 

Thanks I think I will just use NEO

 

17 year old car and the synchros start to go and you blame the fluid? if my sychros started going, i wouldn't blame the redline that was in it currently (though i will be trying Neo soon), i would probably blame the black goo that came out of the transmission when i changed its fluid for the first time in a decade or more. as for "eating" synchros, what you need to stay away from are fluids with a high sulfur content mixture. our synchros are brass and sulfur will indeed literally eat them up. i cannot off the top of my head remember which fluids in particular have a high sulfur content but if you do a little searchy i'm sure you'll find more info.

edit: just looked around. mobil 1 75w90 GL5 is one of them high sulfur content ones.

 

not necessarily. not all trannys have the same type of internals. a fluid that eats our brass synchros may be heaven for a tranny with different build specs and materials. most manuals don't tell you what kind of synth lubes to use so you can't tell when you're out of spec unless someone lets you know or you go researching on your own.

not saying redline is bad, i use redline and it was a noticable improvement over the crap that was in there.

 

I just wanted to say, that after driving around for a month or so, since I switched to Redline MT90, my 2 gear synchro has been a lot better. Im glad it worked.

 

My .o2 on MTL tranny fluid. My experience is with VW transmissions and I have used Redline MTL in several cars with excellent results. These were all A1 and A2 cars (i.e. up to 1992). There is the same argument about the pros and cons of Redline on the VW forums. The Redline MTL is designed for the early cars that have synchros that will not tolerate some of the common additives. I have never had a transmission fail after adding MTL and some of them were driven for 4 years.

I also used MTL in my '89 Saab 900 Turbo transmission. I have been driving it over a year now and the results were dramatic.

The Redline website used to have a good technical article about this issue.

 

http://www.myoilshop.com/

These guys say they can ship Redline to you.

 

I've had NEO in the transmission of my (now former) 240sx. Tranny was fine. I drove over 50k miles w/ it before I sold the car. No problems or complaints w/ that product.

NEO's website: www.neosyntheticoil.com

 

this probably doesn't help much

but I know that the Subaru and BMW community LOVE Redline.

I do know that a synthetic tranny oil will be more "slippery" than dino oil, meaning your synchros won't be as effective. But otherwise, I can't see it doing damage.

 

what about penzoil synth gear oil. i work at a car wash and lube center and get lots of free penzoil gear oil. theres 2 kinds, 75-90 and 90-145 or something high like that. i also got a 90 gxl. anyone try this or heard if its ok? its free so im thinkin about throwin it in my 7 since im in the process of swappin engines

 

I've had mixed results with Redline MT-90.

My first experience was with a fresh rebuilt transmission in my NA 86. Redline made the gear shifts more notchy after the switch from Valvoline 75w90.

My second experience was with my GTUs. The car had 97,000 on it and the 1-2 syncro was frozen. The transmission would grind on every shift from 1-2 or 2-1. I put redline in the trans and presto! The problem disappeared completely in one day. I'm at 115,000 miles now with no problems.

Third experience is with Triangle Power's 90 TII. Redline made his box shift more notchy than the dino fluid that we pulled out.

So what does it all mean? Redline seems to work wonders for worn + tired transmissions. It has great cleaning properties. It might not work as well in rebuilt/tight transmissions.

One reason to explain this is that MT-90 is very thin compared to 75w90 gear oils. I've heard that MT-90 doesn't adhere to the syncro's as well.

 

Using Royal Purple........Great stuff!!!

 

i just bought some mobil 1, so im goin to try that

 

I've always been an Amsoil type of guy.

 

I thought MT90 IS 75W90, so how can it be thinner?

So which NEO was used? HD or RHD? Just curious, cos I'm thinking of switching to NEO too, but not sure which.

I currently have MT90, noticeable difference, but nothing tremendous though, I like it.