What are peoples choices when it comes to Manual Transmission Fluid and Reason why!?

 

currently running neo synthetic ... i think 75w-90. its pretty good stuff and i actually decided to run this because i heard good things here on the forum. it didn't fix any issues but it made a slight difference in feeling. i think if you change it often you dont need to run anything special... since i have full access to other fluids i can change this every 6 months... most people would reccomend neo or redline.

 

uhm my current tranny is runnin 75w-90 mobile one, seems to do the trick just fine, but considering 2nd and 3rd synchros are shot its hard to tell how well it works in the tranny. I just bought a 94 miata tranny to switch tranny internals with so i too will be looking for possibly another choice for transmission fluid. i hear royal purple is supposed to be pretty good..

 

I use Royal Purple. Neo is also great, and I've used it too. Those are the only 2 I've looked into that I'd use, though I might put up with Mobil 1 if I had to. All 3 reduce grinding a little. RP and Neo also allow faster shifts. RP and Mobil 1 have excellent reps with motor oil (Neo probably does too, but I haven't seen much/any info on it). 3,000 mile old Mobil 1 tests better than brand new dino oil, for example. Redline tranny oil is popular b/c it can handle a lot of track abuse without breaking down and allows faster shifts, but it doesn't reduce grinding. Using it to let you shift faster may even increase grinding. That's why I don't use it, but others - including a good number of racers - like it.

This has been asked to death. Forum search will give you more details.

 

i use valvoline syn power 75W-90 in both the 90 FC Vert and the 10th AE

 

Redline MT90, great stuff, comes highly reccomended, helps with old syncros.

 

Royal purple 75w-90 here.

 

Redline MT90 or Royal Purple 75W90.
I've used both, and I can't tell the difference between the two.
I just pick up whatever I can get my hands on easily at the time.


-Ted

 

Redline MT90. I have a short shifter installed (Mazdatrix) and the MT90 seems to reduce some of the notchiness in the shifting.

 

The reason these fluids work so well is because it makes you syncros not stick as well. Hence the faster shifting. I would rather not have to worry about shifting fast and have a tranny that lasts.

 

Mobil 1 sythetic 80/90w shifts smoother than the fluid that was in it originaly

 

What Fluid was in it originally? Do you use the same as the transmission fluid for the rear differential or thicker stuff? Thanks.

 

My guess is Gear Oil. I dunno if it is the same as Differential Fluid.

 

i've used redline for 3 years

and it kind of sort of sucks

use something else

 

+1 for MT-90 and Royal Purple 75w-90.

Prefer the Redline over the RP actually. Will be trying Neo soon.

 

I've tried NEO, Royal Purple, Redline MT90 and my favorite is Redline. There are all good fluids though, but I felt like the Redline gave me a better shifting feel with less gear crunching at higher RPM's. Just my opinion, that 1-2 shift is killer at 7,000+rpm.

 

I've been trying to find Redline MT90 around here, but I can't...nobody has any! It looks like I'll have to order it off the internet if I want it...

Maybe I can find the Royal Purple 75w-90...

 

Royal Purple in the trans and the S/C (ATF) FTW.