Hi all,

Well it is time to change my transmission fluid but I do not know which of the two bellow:


Redline MTL Transmission Fluid 70W80 GL-4 Gear Oil

or

Redline MT-90 Transmission Fluid 75W90 GL-4 Gear Oil that's slightly heavier than MTL

 

I put mt-90 in a couple thousand miles ago and couldn't be happier. There was a very noticeable improvement in shift quality right off the bat - an overall smoothness that wasn't present with the original oil. Either way, I doubt you could go wrong.

 

Some go with a 50/50 mix of MTL and MTL-90 so that you can get good protection with excellent shifting. StealthTL has done this and seems to like it.

 

Hey do you guys know which red line fluid is the best for the 4portAT? And how much fluid do you need to buy?

 

Just to confuse you - heh . I was running MT-90 and have sinced switched to Redline lightweight Sockproof . Main reason I changed was for track work but I've found it to be much better for smooth shifting in daily driving , hot or cold . The difference is night and day .

 

Be careful with Shockproof - as it is designed more for racing transmissions that do not have syncros. This oil has Extreme Pressure additives which are great for the gear teeth protection themselves, but are not good on the syncros. Even the RL site itself says not for use it in syncro Manual Transmissions.

I know Team uses this, but he is using his car mostly for racing in which this may make sense as he may be more concerned with gear wear than syncro wear. This is not the case for most street driven cars unless you track it most of the time!

http://www.redlineoil.com/products_g...6&categoryID=6

If you want to use Redline products, MTL or MTL-90 is what you need (or a blend of these).

 

Fair enough Jax . I let Taka be the guniea pig - he has run it for many kms and had no problems . Like I said the difference has been night and day for me - that's my experience .

 

how many quarts do you need? i was going to change that a long with my oil and diff oil. Basically i need to know how many quarts of oil i need, diff fluid, and the trans fluid. and what is a good diff fluid?

 

Oddly Redline Australia adds Lightweight as an option (with an * of course)
http://www.redlineoil.com.au/oil-fin...ProductID=7589

 

I thought it was a little more in the diff? like 1.8 trans, 1.4 diff? I usually buy 4 quarts and use a little over 3...

 

yeah its 1.8 trans (manual) and 1.4 diff.

btw I along with brettus have redline shockproof and couldn't be more please.

 

After the drain I have to put a little bit over 2 quarts into the fill hole ...

and I have yet to have problems, maybe my tranny is a bit bigger ?

Rear diff took about 1 and 1/2 quart.

ROYAL PURPLE FTW !!!!!!!!!!!!!!


but Im going to try some Redline next time, just for the hell of it.

 

go for the lw shockproof not the mt . Seriously - my changes are silky smooth now

 

I have no problem with RP.

but is the LW shockproof really good for cold weather ? Cuz I hate grinding feel.

 

wft?????

you need to buy 4 qts. gravity takes care of the amount...


beers

 

is fine when ambient is around 5 deg C - can't say what it will be like below freezing .

 

I would not run LW, but that's just me

signed

two broken trannies and two more on the way out

 

are you saying the oil contributed to that ?

 

I believe he's saying Lightweight is not the correct choice. I might be interpreting poorly though.

Our trans is a 75W-90 which would make the Heavyweight the go ahead choice anyway. Read the Redline Shockproof white papers.

"Improved durability in high-performance use is the primary benefit of the Heavy ShockProof™ and along with the improved durability is an improvement in efficiency, but if further improvements in efficiency are desired, and durability is not a major concern, LightWeight and SuperLight ShockProof™ can be used."

EDIT: typed "diff" meant "trans" - corrected.

 

durability is an extreme concern for anyone pushing an RX-8 trans hard, all the serious RX-8 race teams have issues and are constantly rebuilding transmissions to keep them from blowing up during a race if they're lucky ...

 

Team your post is very confusing - we are talking about oil here .
We know you have had issues with your trans - my question is : do you see LW as contributing to that or not ?

 

What part in bold don't you understand?

I run Heavy Shockproof because IMO it makes the trans more durable in the long run. If I wasn't running Heavy Shockproof I'd be using Redline 75W140NS instead (and did before switching to Heavy Shockproof for better efficiency during racing conditions). IMO the lighter fluids break down too easily under high loading and high heat. The trans in general is a weak POS. Trying to get increased efficiency out of it will only result in it breaking sooner, rather than later. It will eventually break though.

I wouldn't recommend running Shockproof oil in a clutch pack differential though. Stick with the traditional 75W90 oils.

 

so let me get this straight Team.
You have blown 2 transmissions and another 2 on the way while using Heavy shockproof . And you are saying not to use lightweight for durability reasons when that is the one recommended by Redline for racing applications .


Manual Gearbox Red Line 'MT90' (* Advantage Option for Racing Only using 'Lightweight Shockproof'.) @ see handbook for Litres

 

Brettus, read the Redline USA site and you'll see why there are different shockproofs. As described in the whitepapers, heavy weight is the "heavy duty" vs the lightweights are for getting rid of every last bit of friction you can while foresaking durability (ie time trialing). Redline USA doesn't recommend any Shockproof for synchroed transmissions FWIW.

 

Brettus, you're making assumptions, rather than being familiar with the facts

The non-Shockproof failures (80W90 and MTL oils) were catastophic blow ups; gears stripped of teeth, etc. The Heavy Shockprrof trans lasted way longer and only needs a 3rd gear synchro set that wasn't inspected during the prior rebuild. The other trans is regular 80W90 oil and is just shy of a catastorphic failure; no reverse gear, whining in 4th gear and other not-good noises

I'm quite familiar with the various weight Shockproof oils. I've been using them for over tens years on a variety of cars. If you're concerned with durability I wouldn't use anything less than Heavy Shockprooof on an RX-8 trans, or 75W140NS if you're concerned that Shockproof isn't the right choice.