I've noticed several people have changed their tranny & rear diff oils to Redline. From what I've read, everyone loves it as it decreases noise, decreases shifting effort, and improves shifting during cold weather.

Has anyone tried using Royal Purple instead of Redline? If so, what are the pros/cons? Also, which product would I need to order from them and in what quantity?

-jc

 

I switched from Quaker's State Advance Q To Royal Purple.

and at the same time, I changed my Transmission & Rear differential oil to Royal Purple also.

Be honest, Engine response is "little bit" better than before. Horsepower I kinda doubt there was any increase. maybe 1 hp? something not noticeable but like I said, its a lil better .

but I think Im going to take my Transmission down soon for MS Flywheel and *maybe* MS Clutch. So I might switch to another brand maybe Redline to see what happens.

 

Tranny takes about two quarts, must be GL4 quality.
Diff takes about one and a half, it must meet GL5 specs.
....don't mix them up.

S

 

i think i'm gonna try the Motul stuff every racing corporation in the world wouldn't use it if it sucked

 

Actally the gearbox can use GL-4 or GL-5.(Owners Manual,p10-4).I have used Castrol Syntec 75W90(GL-5) in my RX-7s and RX-8 without problem for years.

 

Other brands to consider are Mobil or Amsoil. Both are reputable and work great. Main thing is the Synthetics will lube better, longer and give exceptional cold and hot weather performance. No worries then. We did it with Amsoil 75W- 90 and 80W-90 without any issues to date.

Great, Jeff B.

 

I don't find that Redline MT90 works all well in the cold. The transmission really doesn't shift well until warmed up.

I am considering switching to Royal Purple Max-Gear 75W90 to see if it performs better in the cold.

 

I thought the redline performs better than stock in the cold.

 

I noticed that recently with the RedLine MT90, too. Shifting is very "notchy" and can take some effort. This time of year it can take several minutes to get it warmed up and shifting properly.

 

"Some people" use a mix of about one-third Redline MTL, to MT90 - it is much thinner, and improves the shifting DRASTICALLY!

"Some people" would not go back to straight 90 weight, despite what the manual says!

S

 

I use half and half MT90 and MTL and it shifts great cold or hot. I changed it due to the 1st-2nd grind (which went away) and wouldn't think of going back. It shifts so much better than the stock fluid and no tranny problems in +16,000 miles.

 

i dunno if it will work with ours but i've heard magical things about GM synchromesh from many different people with lots of diff cars. alot of focus people use it and their trannys are pretty tempermental

 

I run the royal purple in the tranny and diff, and have noticed nothing but improvement with no downsides. Its a smoother, quicker more direct shift

I also ran the redline in my mazda6, which is good stuff too. Given my experiences with royal purple, I'm sticking with them.

 

did it, love it.

beers

 

What are the exact names of the Royal Purple bottles for the Transmission(Gear Box) and the Rear Differential Box? Pics would help if any one has those! Thanks.

 

Max-Gear 75W90

 

I have Royal Purple in my Engine, Trany and Diff, love it!

 

Question..changed both trans & diff to Royal Purple and have noticed that the shifting is more stiffer? Kind of like a "shck, shck" motion..not smooth, but definitely more reliable in feel? Before, the shifting would alternate from silky smooth to downright fighting the gear change, but now, all shifting motion is the same with the "shck, shck" feel to it..anyone else notice this, or did I messed up with the change (don't know how I can..pretty straightforward flush and fill job). I'm wondering because I don't know what to expect from the fluid change..is this a "good" thing to have this feel or should it be "silky" smooth??

 

Hmmmm... If this improves the shifting DRASTICALLY as you say, then this could make me change my mind about using Royal Purple. Could you expand on how it feels? Have you tried using only Redline MT90?

-jc

 

I think it takes 4 bottle of this stuff to treat your tranny & diff.

 

~)(Guy....

I first switched to MT90 (as called for in the manual) but the shifting was worse than stock (a little bit stiffer/slower) so looked up what Redline products were a little thinner, and found MTL would fit.

Bought some, and found it's a lot thinner than the 90, so went with the one-third mixture. My results were, to me, amazing! I can only go by my experience, and the best shifting car I ever had was a Miata, and my '8 now shifts at least as well, and possibly a little better.

To be fair, I have never used/experienced the same gearbox with RP products.

S

 

That's funny... I used all MT90 in my transmission (and 75W-90 rear diff) and I think it is loads smoother than stock. Maybe I'll try mixing in MTL later to see if it feels better.