ok guys here is my story i replaced my tranny and rear fluids about 14 months ago and i was very satisfied with the results but i noticed a little grinding noise when shifting from 3rd to 4th (at high rpms), but it was no biggie.... about 2 months ago i did my summer tune up in which i replaced the tranny and rear diff fluids but now there is a grinding noise when i shift from 1st to 2nd at high rpms (8000 and up). i already order a set of red lines fluids, but i was just wondering if anybody had this type of problem with royal purple?????

 

i think a few years back there was an issue with red line or purple royal diff fluids- i forget which one (or possibly both).

basically, everyone who used those had to get their transmissions replaced... u should read up on mazda's TSB's for 3rd party differential fluids, or search for the thread on the forum. there was a ton of info on it...

 

my tranny had all the syncros fall apart. I won't use RP in my transmission again.

 

I had the same problem with the tranny. Rear diff on royal purple is ok, BUT the tranny need to be replace with Red line MT-90 GL4, i repeat MT-90 GL4 only. Do not use any GL5 or mix GL4 and GL5 Fluid (that's what Royal Purple is) on the tranny. I try them all and MT-90 so far is the best for my tranny.

 

hmm, how about in an auto differential...just changed my diff fluid to royal purple 75w-90 so this kind of worries me

 

thanks guys for all the info i cant wait to get my red line fluids. I will keep you guys updates once i change the oils

 

That's what I used - rp max gear.

I still have rp in my rear diff. No issues from that.

 

Although I never had a problem with it, I got scared off RP fluid in my tranny. Switched to BG Synchromesh 2 and grinding was reduced. It's been in there a year or more now. Still feels great.

 

i've been using GM synchromesh in my 95 Ranger now for about 50K miles with excellent results. i use redline MT 90 in my RX-7's and so far i have had no problems. in my 85 GS with a 13B, i did however notice more gear whine when initially switching to RP from the conventional valvoline 80W90. the gear whine turned into bad bearings and i subsequently replaced the trans. i'm not sure if the RP caused it but i wont use it in my transmission anymore. i'm still decding what i want to switch over to with the 8...

 

I am using RedLine MT90 Trans and 75W90 Diff and so far 5900 miles and it is great, shift change is Bloody Beautiful....smooth as silk!!

But, it is a little stiff when cold, but this is normal.

At my age my joints are a little stiff too when cold!

 

^^ but your car is... how old? less than a year eh?

 

Yep...I know it is not "old" but I am happy with Redline, IMO way better than the factory trans oil...my tranny is BOLT action smooth in every gear.

 

I out in amsoil about 9 months ago and have been very happy with it. In the diff and tranny.

 

Yep, IMO Amsoil make a good OILS...

 

https://www.rx8club.com/showthread.p...ighlight=royal

Here you go, documented that rp is way to thin.

 

I'm not sure how much you track your car if at all. But I have played with tranny and diff oils for a couple years now and found something that holds up very well in a race application. Now this is definitely not recommended for the average street cat but only because I have not tried in a street app...1 and half qts of Redline 75w90 gear oil and a half qt of Redline ATF in the trans and ofcourse 75w90 in the diff.

Now, in my street car I run Redline half and half Redline MT-90 and MTL in the trans and Redline 75w90 in the diff. I've had no problems what so ever.

 

thanks Bro!

 

Good info

 

Add myself AND Newcastle to the list of failed Transmissions with Royal Purple.
Both of us switched to RP and within a couple months our synchros were FUBAR'd.

29,000 + on the new transmission with Redline fluids and ZERO problems.

 

i ordered my Red line liquids yesterday they should be here soon, i can't wait, im so pissed off with this royal purple stuff i love my 8 i feel like i ve done my 8 wrong

thanks for the info jedi!

 

After switching around a bit, I'm currently using Motorcraft XT-M5-QS because of a tip from the miata.net guys and I must say I like it very much at the moment. I've changed transmission oil brands at every change, but I think next time I'm going to stick with the Motorcraft.

 

hey guys i finally replaced my rp fluids for red lines and there is still a little grinding noise when i shift from first to second at high rpms, but its not as bad as before im begining to think its my tranny eventouht it was shifting just fine before i tried the royal purple stuff

any advices guys???

 

Everyone that I've ever seen whose had a problem with RP was using the WRONG product!!! Which one were you using? You should be using Max Gear 75W90 in both the transmission and the rear end. Do not use Syncromax. I've used these for a long time and Brillo has also been using them in his RX-8. It works great. The problem is that people don't use the correct product and then they blame it on that company rather than their lack of proper oil choice. There is NOTHING wrong with RP at all! It is not too thin.

 

Nope, you're incorrect on that one.

Myself AND Newcastle had transmission failures with RP while using the correct types. (I even confirmed it with you via a PM)

 

i definately had maxgear 75w90. As I said in an earlier post, I still have maxgear in my diff. The transmission felt wonderful with it for around a year before it fell apart.

my dealer asked mazda for a replacement. mazda said no - they would rebuild it. As soon as the tranny was dropped and opened up, they decided they would have to replace it as it was too far gone to be rebuilt. That's how bad it was.