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PostPosted: Wed Nov 25, 2009 3:06 am
by Corey
our tranny has a lsd in it doesn't it


The rear differential on many of the GT-Fours and some alltracs came as a Torsen LSD.

The transmission has an Open Front differential, and a Viscous Center Differential.



so, when you say for find a fluid for the job.. talking about the tranny- why worry if it works with a diff?


The differential in our cars has different lubrication requirements than our transmission.

Our manual states that a 75W90 GL5 fluid should be used in both the transmission and differential.

Unfortunately, this is kinda vague. The transmission has syncros in it which do not work well with a GL5 Differential fluid.

From what I understand, syncros work best in a GL4 fluid. Unfortunately, out transmission is also a transaxle, containing both the front and center differential which use the same fluid.

Those differentials ideally need GL5 Fluid. So, a comprimise has to be made.

This is where Redline comes in with their multi application oils

They made a GL5 75W90 specifically for hypoid differentials (like ours)

They also make a GL5 75W90NS formulation which protects like the 75W90, but without the "Slipperyness" needed for the differential.

This slipperyness is counter productive to the operation of the syncros in a transmission.

But to further confuse matters, I have also read that the Shock protection chemical of GL5 fluid can have a negative effect on "yellow metal" syncros like in our transmission.

Redline markets their 75W90NS as being syncro safe: From their site:

[75W90NS] Contains extreme pressure additives like our 75W90 GL-5 oil, but lacks friction modifiers to balance slipperiness.

[Plus] Improved copper corrosion protection to prolong synchro life



So... Its commonly recommend to use Redline 75W90 NS in the transmission, and straight 75W90 in the rear differential.

Now, from my previous post, i mentioned a redline rep suggested i use their GL4 MT-90 75W90 fluid in my transmission.

This would be great for the syncros from what i understand... but i dont know if the GL4 will provide the same protection for the front and center differentials.

I asked him for specifics on why he suggested that specific oil. I hope to get a response soon.


If anything i have posted here is incorrect - someone please let us know.

Hope that helps.

There is a large "Transmission and Differential" thread on here summing up what each car came with.

PostPosted: Wed Nov 25, 2009 3:13 am
by Landon
helps a lot man, thanks! keep us posted cause i'm curious to hear what'll be best to use for both things. thanks a lot for the tips. i'll check out that thread too.

PostPosted: Wed Nov 25, 2009 4:09 am
by MWP
I recently changed from Castol VMX90 to Redline MT90 in my ST205 gearbox.

There is a HUGE difference.
Gbox is now perfectly smooth, quick and notch-free.

Redline oil is worth the $$$s.

PostPosted: Wed Nov 25, 2009 10:21 am
by Nitro_Alltrac
Our tranny's do not have a lsd. The only lsd that we'll have will be if you have one in the rear. With the stock torsen, you don't have to use any special oil or additives like you do with a clutch type lsd. The torsen is all gears.

As for the oil and the transmission, the issue there is getting an oil that will protect the syncros and the hypoid gears in the transmission and front diff. That's the reason for the factory recommendation for the GL-5 oil.

PostPosted: Wed Nov 25, 2009 9:39 pm
by Corey
Got another reply back from Redline:

Just as we expected - Should run 75W90NS in our transmission due to the differentials.

In an application that allows either a GL-4 or a GL-5, 75W90 viscosity we recommend the MT-90. If your factory owners manual does specifically call for a GL-5, I would recommend the 75W90NS.

Some GL-5 gear lubes can be corrosive to brass, bronze or copper also many are too slippery for the synchros. Our GL-5 gear oils don't contain sufficient EP additives to be corrosive, the "NS" fluids are designed to provide good shiftability with the proper coefficient of friction for the synchros.

Regards,
Red Line Oil





I'm swapping back to Redline 75W90NS as soon as I can. I just looked at Royalpurple's site for details on the ONE tranny fluid they offer, and it says its ideally suited for trannies needing ATF..... So im a bit concerned right now that my poor tranny has been using the wrong oil.

PostPosted: Thu Nov 26, 2009 4:51 am
by YerRandO
anyone try Motul Motylgear 75w-90, meet API GL4 and GL5.

PostPosted: Thu Nov 26, 2009 5:49 am
by Rick89GTS
Corey Darling wrote:......So... Its commonly recommend to use Redline 75W90 NS in the transmission, and straight 75W90 in the rear differential.......

Hmm...I talked to my Toyota Mechanic and he said the dealer uses the same Toyota GL-5 80w90 multipurpose gear oil in the trannys and rear diffs for All-Tracs.

I have previously gone with Castrol Hypoy C in both, but now I'll do some more research before the next change. This is always one of the most debated (and confusing) issues with our cars, LOL :doh:

PostPosted: Thu Nov 26, 2009 6:06 am
by Corey
This is always one of the most debated (and confusing) issues with our cars, LOL



I know! lol. It usually turns into a day long obsession with me every year for some reason. Just waste my time researching because I want the best oil I can find to go into my car.

I talked to my Toyota Mechanic and he said the dealer uses the same Toyota GL-5 80w90 multipurpose gear oil in the trannys and rear diffs for All-Tracs.


Hum.. that appears to mirror what the manual says... but I think that is a bit like shotgunning one oil type onto two different applications.

As was mentioned by Redline, GL5 oils are great for differentials, but not good for syncros. So they made a kinda hybrid oil that protects like a GL5, but is not as harsh on syncro metals - 75W90NS

PostPosted: Thu Nov 26, 2009 6:29 am
by Corey
anyone try Motul Motylgear 75w-90, meet API GL4 and GL5.


If I were to try the Motul oil, I'd try the Motul Gear 300 75W90 because it says its 100% ester base stock like the Redline oils.

What steers me away from this fluid (and now Royalpurple for a similar reason) however is this:

Motul Gear 300:
All mechanical transmissions, gearboxes and differentials with or without limited slip systems, operating under high shock loads and variable speeds


It says it works in ALL transmission, gear boxes and diffs, with or without LSD.

How can ONE oil be good at doing all those things? when we know some GL5 oils can be corrosive to yellow metals, and GL4 grade oils are not suitable for differentials.

Also, clutch type LSD's typically use an LSD additive, where as our Torsen LSD doesnt need an addititve.

That's what I like about Redline's specific application oils. And they go into specifics as to why its appropriate for a given application.

PostPosted: Thu Nov 26, 2009 9:57 pm
by 5thgenbliss
My motor is close to being put back in my car finally:) and with that, i'll be using Redline 75w90NS for the Tranny. I will let you guys know once its back on the road, how it feels. its a JDM ST185 tranny, (is that 152F?) can't remember anymore what the code is.

here's an idea, when has someone checked out GT4OC in the UK to see what they use for their 185s and 205s. Its more popular over there so they must have figured out the best tranny/diff fluid by now:)

teh STI Subbie guys use Redline NS and i believe they have a similar tranny/xfer case setup like ours correct?

PostPosted: Thu Nov 26, 2009 10:01 pm
by Corey
its a JDM ST185 tranny, (is that 152F?)


Is it an RC or standard tranny. E150F for standard tranny, E151F for RC, E152F for the Rally gearbox, E154F for 205 gear box.

here's an idea, when has someone checked out GT4OC in the UK to see what they use for their 185s and 205s. Its more popular over there so they must have figured out the best tranny/diff fluid by now:)


Yeah, couldnt hurt.

I know they do carry Redline over there and the GT4OC sponser Opie Oils does carry it.

When I asked them what they recommend (for motor oil), I received this:

Redline engine oils are of fine quality, in fact we sell them. Others to consider (ester content-wise) are Silkolene Pro S and Motul 300V

PostPosted: Fri Nov 27, 2009 10:37 am
by GrpAGT4
MOTUL GEAR 300 75W90 100% ESTER SYNTHETIC

Motul's highest quality 100% ESTER BASED synthetic 75W90 gearbox oil. Designed for today's high performance vehicles, and all out race cars. This lubricant is virtually unshearable. Its stability at high temperatures make it ideal for extreme conditions. Many endurance professional race teams swear by this oil. Designed for transmission gearboxes and rear axles. API GL4 and GL5/MIL-L-2105C.

i didnt read the whole post so someone may have posted this already

PostPosted: Fri Nov 27, 2009 3:04 pm
by RedCelicaTRD
Alot of the confusion about GL4/GL5 oil come from old information that really no longer applies. It all started back in the late 80's/early 90's when car companies started to use specialized fluids in there vehicles. Many companies started lableing fluids as "lifetime" fluids that never needed to be changed. They did this since there is the constant fear of being sued back in the day if you had a specialized fluid and where the only retailer (it gets all tied up in the Mag/Moss act). This is what led to the people saying GL5 oils will kill brass parts. After 100k or so as the fluid was breaking down and as acid content was getting higher GL5 fluids would start to eat away at the soft metal parts to an extent that would cause failures. However, if the oil is changed on a decent interval there are very few problems with GL5 and brass parts.
Now alot of you might ask why would a manufacture do this? Well after 100k miles, cars where out of warranty :wink:
So in my opnion, GL5 is fine as long as you keep your fluids changed. I run GL5 fluids in both my transmissions and I don't have any problems, but I do try and keep my fluids changed and everything in good up-keep.

PostPosted: Fri Nov 27, 2009 5:42 pm
by 88st165
I couple years back I started to develop a very slight noise when shifting into third on my stock 165 trans (only 50Kmi). I started to get nervous and quickly switched to Redline 75-90NS after searching the forum. Fast forward a year and now I have an awful 3rd gear grind and mind you I only drive the car maybe 3kmi a year. I recently switched to royal purple max gear to give it a shot and its only slightly better at best. Im going to give amsoil a shot next and if that doesnt work then rebuild or get a used 205 trans. Im not saying the Redline fluid was the cause, Im just saying its def not going to be a fix.

PostPosted: Fri Nov 27, 2009 7:12 pm
by 5thgenbliss


Is it an RC or standard tranny. E150F for standard tranny, E151F for RC, E152F for the Rally gearbox, E154F for 205 gear box.

its an RC. i forgot there was a Rally tranny too.