Dont use RP Maxgear in your Transmission.

Use GL-4 ONLY.

I hate products that "support" 2 similar standard. RP Maxgear is one of them, GL-4 and GL-5. (their engine oil is great tho) I know 2 standard are similar (in some way). but im not using them in my tranny,

both my FC and SE use Redline in the tranny, works great :)

Rear use Mobil1 75w90 LS. no issue :)

Your mean FC and FE don't you, I bet you can not find SE on any part of your car..;)

I went to my dealer and bought two bottles of the oem fluid. I'm using that for now.

I had tried out amsoil, but the new transmission still felt notchy with it. it's not any better on the oem fluid, but at least I won't get any surprises down the road like i had with the max gear.

Well, the code name for RX-8 is SE3P.

I know it has FE written all over the car body ...

Mazda Japan probably told the press this is the new "FE3P"(back then)

but with the horrible japanese accent, the press misunderstood it as "SE3P" and published it ... then Mazda is like ahh, whatever.

SE3P ... :(

Somewhat off topic but is there anyone who makes better syncros and shift forks for the 8 transmission. Mine will need a rebuild soon and I would prefer something better.

^^ None.

Just buy the updated shift fork from Mazda.

the Syncros ... hmm there is not much you can do about it. Aisin totally messed this transmission up. if you want better tranny, you should go for the 09+ tranny.

Your gear ratio will change, but its a much better tranny than the pos 04-08

is the 09 tranny a drop in replacement for the older cars?

Yes it is :)

Mazmart used to have some, brand new, I think they were asking for 2K + shipping ?

I thought about the 09 but I have seen a few people on here having problems also. Plus I would like to upgrade the clutch and flywheel at the same time.

hey rotarygod i was using the right oils in the tranny and diff i guess its just one of those things where it just work better for different people :). in my own experience i notice red line made my car shift smoother and also quieter I will choose red line over royal purple anyday.

thanks charles i'll do that!

how about using the tranny from a rx7 turbo II?? if i remember that was the strongest tranny for the 7's :)

There will be some work involved with that swap. Someone here has done it though. I want that swap myself.

As for lube, I just changed mine, as I previously posted I am running a little Redline cocktail of 75w90 and ATF in the trans and 75w90 in the diff. If feels a little differnt than the MT-90 and MTL I was running...shifts still feel perfect to me.

I guess you mean the FD tranny.

Well, FD's tranny can take a bit more abuse than FC's (both are considered as bullet proof, can take mad abuse)

Dunno how Aisin mess this one up ... :(

I like Redline too, too bad the dealer here wants 15 bux a quart. no thanks. maybe when Im out of Royal Purple I go back to Red Line thru online ordering.(Ester FTW!)

^^ i had to order my red line online, no one carry it around my area :(

Redline 75W140NS and no more broken transmissions, just sayin' ...

yeah, it's a GL-5 too, gotta love web experts ...

You want some Redline? I'll be going back to California in a couple weeks and can probably pick some up. I'm in NYC pretty regularly these days (like every other weekend) so if you want I can get it to you.

My advice though is to try the Motorcraft XT-M5-QS. It's quite expensive and generally you have to order online, but it's the only transmission fluid that I've felt is worth the price so far.

I have had nothing but good luck with RP Maxgear 75-90. I'm the original owner and have 62,000mi on my RX8 with zero issues using RP in the engine and tranny. I replaced my tranny fluid again with RP at 50K. I also routinely get 16-17 city and 23-24 hwy mpg.

Redline and Motul are also good products, and I've used them in other cars. I wonder if the folks having issues were original owners and if not, how the tranny was treated.

I love RP and will continue to use it in all my vehicles. I know plenty of people who use it without issue.

btw - I replaced my tranny fluid with maxgear three times during the first 50k miles.

That's break in with oem, redline for a bit, then three maxgear changes.

yeah its GL-5 without the LSD additives. and its thicker than w90 oil.

most if not all other GL-5 fluid has LSD stuff in it ... and most ppl dunno products such as 75w140NS exist :)

so its easier to tell people to use "GL-4" only than explain to them what is LSD Additives. :)

I can get redlines online, with all the coupons and discounts, it will cost probably hmm 7-8 bux each. :)

thx anyway tho ;)

hey guys just a little update..

i went on a trip yesterday (crab monthly rx8 sushi meet) and after 100 miles my tranny is not grinding from 1st to 2nd at high rpms, i love this red line stuff :):):):) couldn't be happier

I'm still going to use RP. There's absolutely nothing wrong with it. It's great stuff and has always been smoother than anything else I've ever used. Then again I take care of my transmission and I suspect it's more of a driver issue than an oil issue. There are 2 weights of it available btw. 75W90 and 85W140. Nothing wrong with Redline. It's a great product. RP gets a bad rap from those who can't take care of things though. I know that statement will probably make some mad but I stand by it as it's the most logical answer.

/\
Got to agree with RG on this one..
RP are a very reputable company, I don't think they would market a product that would cause damage when used correctly.

I also believe that many of the "transmission issues" are owner/driver related.
These transmissions Series I and II take some time (miles on them) to loosen up.

And yes I also recognize that the early 04-05 RX-8 transmissions has suspect changing Forks.

This includes a little care when the gearbox is cold.

Personally, I use Redline.
GL4 for Trans, GL5 for Differential.

EDIT:..
I also believe that ALL the Gearboxes should have their fluids changed WAY before Mazda's recommended Schedule.

i agree with you guys and i appreciated the info and experience everyone had with royal purple, and i agree, it also depends on how the car is being driven.

but the issue here was very simple.

my tranny was grinding shifting from 1st to 2nd at high rpms using royal purple,
now is not grinding using redline. End of story! thanks for your comments guys!!

:):):):):):):):)

p.s. i just wanted to share my fail story with royal purple :(