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View Full Version : Manual Gearbox 75 X90 OR Dexron II/III ?, 1998 ST 2O4 --- Puzzled



ALAN
10-03-2010, 12:22 AM
Car is a 1998 ST204R SXR 2.2 NA 5S=FE engine 5 speed manual gearbox.

I'm puzzled , some posts say dexron II / III in the manual gearbox , some 75 x 90 Gearbox oil , the Chilterns manual doesn't refer to a gearbox atall but a manual transaxle in which is says 75 x 90 gear oil is the go , almost as though refering to a 'gearbox and differential' is somewhat bad maners.--idiots--.

Anyhoo I'm presuming that the gearbox and diff share the same lubricant (or have I got that wrong and the gearbox shares the engine lubricant ?) and that the fill is just under 2.0 litres/US quarts--- but what is the lubricant ?

Jeez it shouldn't be this hard :runaway:

Grot
10-03-2010, 12:39 AM
I know on the 5th gens, it reccomends ATF.

But alot of people run Gear Oil.

The 6th gen may be different.

And the Transaxle is the gearbox/transmission. Whichever youd like to call it.

ALAN
10-03-2010, 03:00 AM
I know on the 5th gens, it reccomends ATF.

But alot of people run Gear Oil.

The 6th gen may be different.

And the Transaxle is the gearbox/transmission. Whichever youd like to call it.

Thanks for the reply , so the gearbox and differential share the same lubricant ?
Do you know if anyone uses Royal purple Syncromax for this ?

Funkycheeze
10-03-2010, 03:06 AM
Woah woah.

Gearbox: 75W90 gear oil. GL5 is necessary as the front diff and transmission share the same fluid. Make sure it does not have slip additive (for use in limited slip rear diffs). Redline makes a 75W90NS for this exact application.

http://www.redlineoil.com/product.aspx?pid=47&pcid=7

For those of you with alltracs, the 205s can use the same oil in the rear diffs as it is a torsen limited slip. The NS fluid actually helps to increase the torque bias ratio (amount of torque transfer possible), which is a good thing. Older alltracs qand other cars with clutch type limited slips need to use the 75W90 with slip additive.

I would not use ATF even in a 5th gen. A good synthetic 75w90 gear oil rated to GL5 without slip additive is ideal.

Grot
10-03-2010, 03:10 AM
i had 80w90 in my 4th gen.

I didnt have any issues with it.

ALAN
10-03-2010, 03:41 AM
Ah Ha all good , thanks , after searching more I'm coming up with a manual transmission fill of 2.6 litre (approx 2.75 US quarts) would that be about right ?

KoreanJoey
10-04-2010, 04:26 AM
For those of you with alltracs, the 205s can use the same oil in the rear diffs as it is a torsen limited slip. The NS fluid actually helps to increase the torque bias ratio (amount of torque transfer possible), which is a good thing. Older alltracs qand other cars with clutch type limited slips need to use the 75W90 with slip additive.

You are high...

the slip additive is for CLUTCH TYPE LSDs so that they slip smoothly instead of skipping on engagement/disengagement around corners. NOT for torsen, and not viscious LSDs. Torsen AKA: Helical doesn't use clutches to create torque bias. I honestly doubt the LSD additive would hurt a non-lsd part but I guess it could (I'm not really sure WTF is in LSD additive, I just know it smells like ass).

Funkycheeze
10-04-2010, 05:40 PM
Yeah - that's what I was saying...

75W90 NS (does not contain slip modifier) for manual transaxles and torsen diffs

75W90 (contains slip modifier) for clutch type LSDs (also ok for open diffs)

ALAN
10-05-2010, 03:38 AM
Yeah - that's what I was saying...

75W90 NS (does not contain slip modifier) for manual transaxles and torsen diffs

75W90 (contains slip modifier) for clutch type LSDs (also ok for open diffs)


What is the stock diff in a ST204 (2.2ltr motor) with a standard 5 speed manual box , LSD or plain ole manual one ?

KoreanJoey
10-05-2010, 04:39 AM
If it's ok for an open it'll be ok for a torsen. Again, there's nothing to SLIP in a torsen LSD.

Funkycheeze
10-05-2010, 04:54 PM
I'm not saying that you can't use the diff oil with a slip additive in a torsen diff. However, when the torsen starts to lock up, and the worm gears get jammed into the side pockets, a lubricant with the slip modifier will allow the gears to turn more than a lubricant without.

It gives only a slight increase in torque bias ratio - nothing crazy.

and the front diff in pretty much any transaxle is open (a few fancy or aftermarked ones will be torsen or viscous coupling), but you need to use the lubricant without slip additive (75W90 NS) so that the synchros work properly.

KoreanJoey
10-06-2010, 07:33 AM
No, it wont.

Funkycheeze
10-06-2010, 04:37 PM
Yes, it does.

Believe me, I've tried probably 5 different fluids with my Truetrac, and ones without friction modifier give a noticeable amount of extra lockup. Read here on why friction is still a part of how helical locking diffs work:

http://www.torsen.com/general/general_faq.htm

Smaay
10-08-2010, 01:54 AM
OMG who told you to put Dextron III in a manual transmission, Put your foot in their ass now! that is a 0W oil and will destroy your gears! manual transmissions use GEAR OIL! 75W or 80W is fine.

If you dont believe me, try it and see what happens

There is a reason Dextron III is called ATF fluid....ITS FOR AUTOMATIC TRANSMISSIONS!!!!!!! and toyota power steering :)

Grot
10-08-2010, 02:06 AM
The BGB calls For ATF i believe.

bloodMoney
10-08-2010, 02:10 AM
I put 75-W90 in mine. WITH a quart of penzoil synchromech just for good measure. I've got 144001 (yes, exactly) miles on the trans and it doesn't grind anywhere through the RPM band. I bought it a year ago, it almost immediately got a new motor in and it got 23,000 hard miles on it since then.

This is what I would recommend for anyone refilling a manual box.

KoreanJoey
10-08-2010, 03:51 AM
Unless you're dumping in a quart of LSD additive in it, it shouldn't make any difference in the mechanical control of a torsen LSD. It's gear to gear binding, not friction. The reason you might sense a difference is if you're preload is incorrect.

ALAN
10-08-2010, 07:03 AM
Anybody used this stuff , and how does it go ?

Amsoil Synthetic Manual Transmission and Transaxle Gear Lube available with: MTG 75w90 & MTF Synchromesh Transmission Fluid

AMSOIL Synthetic Manual Transmission and Transaxle Gear Lube (MTG) is a premium blend of the finest synthetic base oils and advanced, high-performance additives. It is formulated specifically for maximum protection in the most demanding manual transmission and transaxle applications where an extreme pressure GL-4 gear lube is specified, including those where high horsepower/high torque engines and towing or heavy loads increase transmission stress.

Luni
10-08-2010, 07:20 AM
I dont give a rats ass what Toyota says in this case. Ill never run GL5 fluid in a FWD toyota tranny again. They think the E153 needs GL5 cause it "contains hypoid gears" which it does NOT. GL5 formulation is rated for HYPOID gears. Its GENERALLY ran in rear diffs. However, Alltracs/GT4s use it in their front diffs, which share fluid with the trannies, so they DO use GL5. E153s, S54s, C60s, ETC (FWD) trannies do NOT use hypoid gears, they want a GL4 because its formulation is what best matches the makeup of our transmissions

GL4 rated 75/90 non friction modified is what you want. Pick a brand and go with it.

Some guys run ATF and yes, the BGB calls for THAT too, but it also was revised later on for a GL5, and then in cars that kept the transmission, a GL4. Now in ALL of toyotas FWD transmissions, their fluid type calls for a GL4. Gee. I wonder why. They must have LEARNED something about fluids over the years.

If youre bored, sign up for an mr2oc account if you dont have one and read these threads. Part 1 is just mostly a pissing match between 3 or 4 guys against 1 guy (Byron) but 2 and 3 gets shit done.

Tranny Lubrication Requirements series:
Part I:http://www.mr2oc.com/showthread.php?p=1780521
Part II:http://www.mr2oc.com/showthread.php?t=173975
Part III:http://www.mr2oc.com/showthread.php?t=178093

Basically in a nutshell by the end of part 3 its decided through all sorts of contact with fluid manufactures (Redline, Amsoil, etc) the requirements Toyota laid out are wrong and the fluid companies USED to recommend what Toyota said, but now they all recommend a GL4 fluid for these trannies (ALL but the GT4, it has hypoid gears in its differential, so they still call for a GL5 in it).

Trust me or not, its not my car. I know what Im talking about, I know what Ive read, and I know what I run. Choose a fluid and live with it.

Funkycheeze
10-08-2010, 06:18 PM
the new GL5 oils will not damage the synchros like older GL5 oils did, so there is no drawback to using them in a FWD transaxle. It is often the case that GL4 oil without friction modifier is easier to find, and is okay to use in tranaxles without hypoid gears.

Also, would someone please explain how torsen gears can bind without friction?

Luni
10-08-2010, 06:31 PM
I still gotta say I disagree with you.

Go look at the fluid manufacturers sites. They do NOT recommend GL5 for our trannies anymore (unless you have an alltrac), furthermore Toyota themselves recommend GL4 for all the new FWD trannies. And for whatever reason theyre still to stupid to revise their reason for calling for GL5 on S54s, E153s etc.

Ive done way too much research on this stuff, to be swayed on it. GL5 IS corrosive to yellow metals. Im never running it. Do what you want. I wont run GL5 again. I was running it in my MR2s tranny when out of the blue my first gear syncro died. The odd thing about this is I was on a road trip. I left my house having my tranny shifting like butter. I stopped for my first fuel stop, still like butter. Second fuel stop, still fine. Third fuel stop, (keeping in mind nothing but accelerating onto the freeway and 5th gear for hours at a time between stops, so no real first gear use or abuse), cant get it to go into first very easily. Ever since then its been fucked. Sell my car, new oner pulls trans apart, finds out first gear syncro is broken.

I was running Toyota Gear Oil Super (which is a GL5 hypoid oil they recommend for my tranny). Yeah, I know, it MIGHT not have caused the issue, but you cant say it didnt, cause it is the WRONG fluid for the tranny.

So yeah, theres my experience. Take it for what its worth (maybe nothing, maybe something).

Funkycheeze
10-08-2010, 08:35 PM
Up to you. The GL4 stuff is cheaper anyways.

Much easier decision for me to make - MT90 (GL4) in the transmission, and 75W140NS (GL5 without slip modifier) in the rear end.

Luni
10-08-2010, 10:40 PM
Thats exactly what Id recommend.

Facime
10-09-2010, 01:23 AM
OMG who told you to put Dextron III in a manual transmission, Put your foot in their ass now! that is a 0W oil and will destroy your gears! manual transmissions use GEAR OIL! 75W or 80W is fine.

If you dont believe me, try it and see what happens

There is a reason Dextron III is called ATF fluid....ITS FOR AUTOMATIC TRANSMISSIONS!!!!!!! and toyota power steering :)


You couldnt be more wrong. Many manufactures call for ATF in their manual transmissions. Some have been respec'd to gear oil and some that were originally gear oil have been respec'd to ATF and in some cases Dex6 (synthetic). There are benefits and drawback to each as already discussed here. Never assume a manual trans reguires gear oil JUST because its a manual trans.


P.S. I decided on MTL for my alltrac with a crunchy second gear and after a week of running it, shifts were noticably improved.

KoreanJoey
10-09-2010, 07:16 AM
Um... Some hondas run 5w30 in their manual transmission IIRC.

GEARS, as in metal, retained by metal, not forced against.

http://www.flashoffroad.com/features/Torsen/Work/torsen_works.htm

Luni
10-09-2010, 07:22 AM
Most Hondas run 5w30 in their manual trannies actually.

And Toyota originally called for ATF in the S53s S54s and then TSBd it and changed it to GL5 which in my opinion is even worse.

Funkycheeze
10-10-2010, 06:40 AM
As soon as one wheel overspeeds without the other side having an equal amount of underspeed (as in a turn), and the axle shaft starts to exceed the speed of the center carrier, the shaft tries to drive the worm gears. This jams the gears against the side pockets, since you can use a worm to drive a gear, but not the other way around. This locks up the slipping wheel.

This jamming which stops the worm from turning is caused by friction, which can be increased with the correct lubricant. On a small racing car I used to work on, we tried running a torsen diff with a multitude of fluids, and found that the ones with the least friction, gave the best traction. The same has held true with any gear driven LSD I have encountered in a car.

"The Torsen differential is simply a torque multiplier that works through the use of friction generated by thrust forces from the internal gearing."

Directly from the info page from Torsen Inc, the inventers of this kind of diff.

http://www.torsen.com/general/general_faq.htm

Luni
10-10-2010, 06:54 AM
Not all alltracs have Torsen LSDs in them.

KoreanJoey
10-12-2010, 06:43 AM
Directly from the info page from Torsen Inc, the inventers of this kind of diff.

http://www.torsen.com/general/general_faq.htm

Um... no, they bought the rights to the invention. Like most big companies do.

It is friction, just not friction you're going to change via fluid. Dude, it's gear binding due to the two sets of worm gears rotating at different rates from each other (one set of gears per axle; sometimes more for larger axles/differentials). You're not going to cause slip on metal gears with some LSD additive, not even a little. The torque bias is set by the side gear angles in contrast to the worm drive gear angles. They are set to engage and disengage from each other when traveling at different speeds from each other causing the torque bias split.

Basically, a torsen will create it's proper torque bias at all times due to it's design (drive gear vs side gear angles) , or it'll break.

KoreanJoey
10-12-2010, 06:55 AM
However, you can run different viscosity fluid all together (50-75 VS 75-90) to change the actual torque being received at the gears themselves causing a greater or lower resistance to differentiate (same torque split but more or less torque being received to the drive gear) but that'd be equivalent to making more or less torque overall.

Funkycheeze
10-12-2010, 05:30 PM
I guess you'll need to try it for yourself. Stupid argument anyways - 'engaging and disengaging gears' in a diff?

Laf.

KoreanJoey
10-14-2010, 06:17 AM
...

The idea that you can make metal on metal engagement slip with LSD additive when contacted at a specific angle is pretty damn funny.

I was trying to dumb it down for you... but ok.

http://www.torsen.com/images/differential_forces.jpg

Can you tell me where LSD additive would cause slip?

Funkycheeze
10-14-2010, 10:36 PM
Different fluid will change the friction coefficient between the worm gears. This friction force is shown clearly.

Also, they don't put thrust washers in there for shits and giggles.

The oil used will change the coefficient of friction between mechanical parts immersed in it. As soon as a side shaft overspeeds, trying to drive the worm, not only is there friction between the gear teeth, but also between the ends of the element gears and side pockets.

Here is a real simplification:

When you have a force acting from one face to another, unless the force is normal to the mating surface, there will be a shear force between the components. This is pure physics. This shear force is opposed by friction between the components, which is a product of the normal force between them and the coefficient of friction.

Thereforce, you cannot say that frictional forces are not present in a Torsen diff, and that a change in the coefficient of friction would have no effect on its operation.

And remember, the whole purpose of slip additive is to decrease the coefficient of friction in clutch pack type LSDs. This modification of the Cf also applies to metal to metal contact surfaces.

Out of pure curiosity, have you even tried fluid with and without friction modifier in a torsen/helical LSD?

KoreanJoey
10-15-2010, 04:15 AM
Definitely have not. But I'm sorry, It's not a horizontal sheer force, it's coming to at a predetermined angle to create gear bind against the worm gear at set variations in axle speed. Hence, the TBR is a constant established during the construction of the unit. Yes, you can change it through pre-loading the worm gears creating a constant application of torque from one axle to the other. But in the end, the TBR, again, remains constant on slip.

Funkycheeze
10-15-2010, 04:37 PM
By definition, the orthogonal component to a non-normal force on a plane is a shear force, at 90 degrees to the plane.

This interacts with friction between the components, and a change in frictional coefficient will have an effect on the original force (and its direction)

Not to mention the effects a change in fluid will have on all frictional torque values shown on your diagram.

KoreanJoey
10-17-2010, 02:14 AM
Not to mention the effects a change in fluid will have on all frictional torque values shown on your diagram.

Which in turn, would equal to the same TBR, again.