MTL info/recommendations

[Alcibiades]

'93 Corolla is ready for a manual trans. fluid change. Calls for GL-5 75w-90.

It's soon to get Redline 10W-30 in the motor, so I thought I'd try their 75W-90 NS, because that is the only GL-5 gear oil they offer. Their website says this about it:

This GL-5-type geal oil doesn't contain the friction modifiers for limited-slip hypoid differentials. This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting. Can also be used in racing limited-slip differentials where weak spring design causes too much wheel spin.

Can somebody explain that to Mr. Ignoramus Alcibiades here, and tell me whether that means it's alright for me to use or not?

I'm also considering these from Amsoil, because these are what their website specs for my car under GL-5:

SEVERE GEAR™ Synthetic Extreme Pressure (EP) Lubricant 75W-90 (SVG)

and

Long Life Synthetic Gear Lube SAE 75W-90 (FGR)

Can an Amsoil-knowledgeable person such as Pablo enlighten me about these?

Any other recommendations? I'm wide open on this....

Thanks!

 

[Pablo]

I would go with the FGR only because the vis is a bit lower and the price is lower as well. Both are API GL-5 & MT-1 rated. The SVG is really additized towards protecting HD differentials, while the FGR will protect and lubricate better in your transmission.

OH yeah - if the Redline is MT-1 rated, it should do fine. I will say this, I ran it in my Toyota truck 10+ years ago and shifting was a bit difficult to engage when cold, I drained a bit and added some ATF (I know, I know) and it shifted much better.

 

[MolaKule]

quote:

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This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting.

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And this is born out by testing or is this another shop myth?

quote:

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Q: What are the main requirements for a manual transmission lubricant?

A: Manual transaxle fluids need to be a GL4 or GL4/5 dual rated fluid.

Here are some points I always make with regard to MTL's:

1. The lube needs to have the correct viscosity for HP and gear loads matching; General GL5's for hypoid differentials are generally too high in viscosity for cold weather shifting. The fluid needs to have good anti-shear capability at high temperatures.

2. The lube needs the proper friction modification for good synchro engagement. General GL5/MT-1's for hypoid differentials don't have this.

3. The EP package needs to be sintered sychro and brass synchro metal compatible; not all GL5 hypoid differential fluids are safe for yellow metal synchronizers, especially the cheap dino fluids.

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Most modern gear lubes have metal deactivators and corrosion inhibitors to guard against copper-alloy staining and corrosion.

 

[Alcibiades]

Thanks for the info. This is raising more questions, though. Why would the trans. in this car need a GL-5? According to the specs from the Redline website, GL-5s are typically needed only for the higher pressure of rear wheel drive differentials or "unique design" manual transimissions that require extra protection. I thought the Corolla was about as run-of-the-mill as one could get. I don't have the manufacturer's owners' manual any more. Could the specification for GL-5 in the Haynes repair manual be wrong?

Thanks for your patience and information. There seems to be a whole gear oil vocabulary with which I am only beginning to be familiar.

 

[muddawgs]

several on the board has used a synchromesh mix with good results also in prizm/corolla. specialtyformulations also makes great tx fluids. the mtl-p or r would work fine and is less than the dealer oe. i would stray away from the dual rated gear lubes.

synchromesh mix

 

[MolaKule]

It could be the Corolla MT has a gear cut on one or more gears that requires more than a GL4 level of protection can provide.

 

[Pablo]

I have heard what Mola says to be true. With the really lighter GL4 fluids engagement can be notchy, but not for syncro reasons.

 

[Alcibiades]

Spoke to my mechanic this morning; he concurs with you, Pablo and Molakule.

Right now, I'm leaning towards Amsoil FGR, unless anyone knows of a reason to persuade me otherwise.

(Speak up soon!)

Thanks.

 

[bmwtechguy]

I would lean towards the MTL's from Molakule and his Specialty Fourmulations company on this one. Others have reported excellent results and shift feel using SF MTL's. His formulas are designed for the specific application and friction requirements of syncronizers in a manual gearbox. While the FGR may work ok for you, it is still primarily a differential fluid and is designed as such. If I did not know the performance of the FGR in my particular application, I would rather go with the specific designed-for-synchronized-gearbox fluid from SF.

 

[Drew99GT]

Ah, Corollas (most Toyota manual transaxles) take GL-4 OR GL-5. That's what my 94 Corolla specs in the owners manual. Aftermarket repair manuals say GL-5. I've tried every synthetic 75w-90 out there, including 2 GL-5s. DON'T DO IT! GL-5 synthetic won't even shift. I tried Redline MT-90 (a GL-4). Pretty horrid as well. Specialty Formulations MTL-R was decent, but the best is still dino 75w-90 GL-5. I'm sure a dino GL-4 would be even better. I cut the 75w-90 with .75 quarts of Pennzoil synchromesh over the winter and that was just butter, but went back to all 75w-90 Valvoline dino GL-5 for summer. SMOOOOOTH.

Redline oil in a 93 Corolla??? The oil's worth more than the car!!!!!!!!!!!!!! I'd save your cash and use dino in that car. Mines had dino all it's life and whenever the valve covers open, it's spotless and cam wear is non-existent.

 

[Alcibiades]

HMMM. That is some food for thought. The Amsoil FGR is already ordered, so we'll see how it works, and let you know. If it doesn't work, I'll probably try the Valvoline dino, and if all else fails go to the local Toyota dealer shop with credit card in hand.

And as for the Redline being worth more than the car....Yeah, I know, and so is the Amsoil, for that matter.

But I'm a bit of an oddball and I like to experiment.

For me, much of the justification is just in the fun of trial and error. As you rightly point out, it's not as though I have much to lose.

 

[Alcibiades]

Looking through some old files, I found the owner's manual. It specifies "multipurpose gear oil API GL-3, GL-4, or GL-5, recommended oil viscosity SAE 75W-90.

This sounds to me like Toyota did not want to be terribly particular with the recommendation, so hopefully the Amsoil FGR will be just fine. It is interesting that yours was problematic, Drew99gt. We'll see what happens.

It also raises the question, why would the Haynes book only state GL-5?

 

[GarrettSocling]

I'm using SF MTL-R, and it seems fine. I believe Boxgrover has used both the MTL-R and MTL-P and thought both were fine?

Interesting, why would dino GL-5 and GL-4 have better shift quality than a high-quality synthetic? I'm primarily intersted in shift quality, with protection being 2nd and fluid durability being third. The MTL-R is only 15k old tho, no time for testing now! I know that the Coastal 75W90 (cheapest I could find) felt nearly identical compared to the OE fluid.

 

[jeepman]

quote:

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Originally posted by Drew99GT:
Ah, Corollas (most Toyota manual transaxles) take GL-4 OR GL-5. That's what my 94 Corolla specs in the owners manual. Aftermarket repair manuals say GL-5. I've tried every synthetic 75w-90 out there, including 2 GL-5s. DON'T DO IT! GL-5 synthetic won't even shift. I tried Redline MT-90 (a GL-4). Pretty horrid as well. Specialty Formulations MTL-R was decent, but the best is still dino 75w-90 GL-5. I'm sure a dino GL-4 would be even better. I cut the 75w-90 with .75 quarts of Pennzoil synchromesh over the winter and that was just butter, but went back to all 75w-90 Valvoline dino GL-5 for summer. SMOOOOOTH.

Redline oil in a 93 Corolla??? The oil's worth more than the car!!!!!!!!!!!!!! I'd save your cash and use dino in that car. Mines had dino all it's life and whenever the valve covers open, it's spotless and cam wear is non-existent.

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Drew is dead on with this post. I had a 97 Prizm (identical to Corolla) and tried the following 75W90 Gear Oils; Mobil 1 Synth, Supertech Synth, Amsoil MTL Synth, and 2 other dinos I can't even remember at this point. Also tried some Lucas Tranny Fix (big mistake before finding BITOG). All of them were terrible for a variety of reasons too lengthy to mention here. Finally I found a post here of someone who used 1 quart of Pennzoil Synchromesh, and tanked up the rest with dino 75W90 gear oil. I tried it and after 7 fluid changes in 2 months, I finally found something that worked. The tranny shifted like new almost immediatly, and just got better as I drove it. That Synchromesh mix is the only solution that worked for me.

By the way, the Haynes manual I had said GL-5 as well, and it was wrong. The 75W90 fluids that said they were for differentials were all garbage, and anything Synthetic was the same. I wound up using some dino 75W90 that was GL4/GL5 dual rated (I think it was Advance Auto house brand) that specified use in manual trannies and the Synchromesh, and it worked perfectly.

 

[Pablo]

It really sounds like these trannies need a very viscous fluid, minus a high level of EP additives.

It used to be that there was no such thing as a non-synthetic 75W-90. Even in 93(?) This is puzzling.

Let me know how the FGR works. I'll still bet it will be better than the SVG.

Drew99GT - what Amsoil fluid did you run?

 

[Drew99GT]

It was the S2000 gear oil I believe Pablo. Got 6 quarts cheaply from a neighbor (amsoil dealer) a few years back. Actually, that stuff was the best GL-5 synthetic I tried. The worst was Pennzoil synthetic GL-5. Upon taking it for a spin around the block after installing that stuff, I basically had to limp home in 1st cause it wouldn't shift!

In all actuality, I really think the issue, at least with my car, is the transaxle and not the fluids. Many of the fluids I've listed have worked flawlessly in other makes and models from members of the board. My trans is plain worn out; the differential pinion bore has major clearence now and when I give it gas or let off the gas after driving for a while (when things are hot and up to temp), it goes CLUNK/CLANG. I have to really ease off the gas when decelerating.

 

[GarrettSocling]

So I should thoroughly clean my drain plug, put my MTL-R in a sealed container, and try 3/4 quart of Synchromesh and top it off with a quality dino 75W90?

I'm game. How comparable is the 7th and 8th gen Corolla transmission to the 9th gen transmission?

 

[tdi-rick]

quote:

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It used to be that there was no such thing as a non-synthetic 75W-90. Even in 93(?) This is puzzling.

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Pabs, Castrol has had a 75W-90 GL4/5 dino tranny fluid since the late eighties here at least called Multitrax that was well known as being the fix in a lot of gearboxes. I think I started using it in '93, and used it for years. I shudder to think how much VII is in it, and how quickly it must shear, but it was the only reasonably priced alternative that worked. A number of race mechanics I used to know swore by it as well.

 

[Pablo]

My memory is fairly rotten....could I have been thinking 1983?

 

[Alcibiades]

It seems from all this like the Corolla manual trans. from the '93 era is rather picky. How odd. I would have thought it to be about as ordinary as you could get.

My Amsoil shipment arrived today, so it's going in soon.

Allow me to ask one more ignorant question: What exactly is a synchromesh fluid? And which brands of it am I likely to find locally such as at AA or AZ?

I just want to be prepared in case I need a quick fix.

Thanks