I ran with redline in diff and transmission for about 25,000 miles. it was much better than stock.

After that I tried out royal purple in both diff and tranny. I can't distinguish any difference when the car is warmed up. But when the car is cold, the royal purple is nicer, as the gear shifts are almost normal. With redline when the car was not warmed up, shifting was notchy and rough feeling.

 

Nevermind...their website has the info I want.

Click me!

Also, based on the RX-8 manual, it looks like Max Gear is the way to go.

~ Matt

 

I get the same cold grind with RP (and the stock fluid). It's smoother with RP than the stock fluid: less resistance when cold, and when warm, it's even smoother. To reduce the grind, pause for a split second before engaging the next gear.

 

check pm

tell em swoope sent ya..

beers

 

Hm, sounds like i'll be going with the rp max gear 75w90.

Gonna be putting in my act clutch and flywheel soon, and I wanna kill two birds wiff one stone. Prolly match the brands and stick with rp. Is there a specific type of tranny oil I should look for? Or does rp only offer one.

I should prolly look myself, but..I like opinions.

 

rp max gear 75w90

does both tranny and dif..

beers

 

^heh. Don't I feel stupid?

Oh well, just me being honest.

That's what forums are for, right?

 

From what I understand the OEM is a synthetic trans oil already and it dose not grind the gears when cold. Makes me wonder if it is worth switching it.

 

its well worth it.

 

If yours doesn't grind gears cold, then RP won't either. I basically get same or better feel after switching to RP. It's not worse in any respects.

 

how many quarts should I buy if i'm gonna replace the fluids for tranny and diff.?

 

4

 

Thank you.

 

Switched to redline about 10000 kms ago . Was really looking for an improvement but could not detect any . Mind you I did not buy the car new so who knows what was already in it.
Gear change has always been slick . Only gripe is the whine in 6th - presume everyone has that ?

 

so 4 qts. is enough for both 6 speed tranny and rear diff?

 

yes, more than enough.

 

i think i will do this too.

 

I had my 30k service done and Max Gear 75W-90 put in the transmission.

My first impression was that the shifter effort is considerably lower. Now, after driving around a bit, I've also noticed that shifting into first higher than around 25 mph can create a bit of a crunch, even when rev matching. This wasn't the case before.

One thing I want to try, but haven't yet, is to see how the high rev 1-2 and 2-3 shifts are. I've had problems with the stock fluid in the past where, even with the clutch to the floor, you get a grinding noise when putting it in gear.

Plus: Reduced effort, better "feel"
Minus: Some trouble downshifting to 1st gear
Unknown: Hi-rev upshifts...


~ Matt

 

downshifting at 25 mph into 1st gear.... are you sure the trouble is not because of the wear you do to it when you do that?

 

Speaking of this...I switched to RedLine fluids at 30,000 miles and am now nearing the 60,000 mile mark and will be switching to RP (it gets cold up here in WI). What do people think about mixing the leftover RedLine with the new RP? I hate to just pitch half a quart of MT-90 and half a quart of 75W90.

 

^ should be fine. I didn't do anything special from my switch from RL to RP

 

Just switched from redline to RP Max-Gear 75w90 for both the tranny and diff at 42k miles. No more hard cold shifts into 1st

 

I just changed from Redline to Royal Purple. The Redline was in for a little more than 3,000 miles, but I just didn't how it was crunchy on the 1-2 and 2-3 shift when cold. After the Royal Purple went in, I can say that the shift quality throughout the temperature range is much better. I should've gone with my instinct to go with Royal Purple in the first place rather than get Redline since I wanted different oils for the differential and the transmission.

 

It seems like I'm the only one, but...my tranny actually feels better and sounds better when it's cold...? I've got the stock fluid (got RP waiting to go in), but the tranny WILL GO INTO GEAR EASIER when its COLD, and the SYNCROS make LESS NOISE when it's COLD!!

But... I grinded 2nd gear at high rpm for the first time yesterday (was properly warmed). Maybe throwout bearing, maybe syncros, or shift fork, I don't know what the deal was with that.

 

Might be a stupid question, but can I use the 4 Quarts of the RP Max-Gear 75w90 oil I just ordered for both the transmission and differential? If not, anyone in SW houston wanna buy two bottles for $16 bucks?