Gear lube question

What gear lube should I use in a borg warner T85N with a r11 over drive?

 

https://www.jalopyjournal.com/forum/threads/borg-warner-od-gear-oil.797663/

 

I used google.
Scroll down to the oil:
https://www.fifthaveinternetgarage.com/overdrive_parts.php

 

I use 80/90 house brand in mine nothing special

 

Can anyone post up a pdf of the owners manual, or a link to one online? Let's see what the OEM recommendations were. Thanks.

 

Some bad advice is often given about transmissions with white metal parts (bronze/br***).

Under no cir***stances whatsoever should you ever use any gear oil that is rated API-GL5, or higher.

Those gear oils erode white/yellow metal.

They are for differentials, not transmissions.

 

And I'm still looking for that photo of any br*** part that was damaged by gl5 oil...

 

https://www.machinerylubrication.com/Read/28958/ep-additives-effects

 

You keep saying that.

Ask at your local Chevrolet or GMC dealership.

Find a tech or service writer that was working there in the 1980's.

You will find out just why NWC T5's have a reputation for early failure, and why there were over 20 part numbers for field service replacements.

 

Thank you.

 

So...active sulfur in some EP additives reacts with the copper within the br*** or bronze. It can be a problem in highly stressed bronze worm gears in large equipment.

Still wondering what this has to do with the synchro rings in the old manual transmissions we use, and the use of modern GL-5 gear oil that says on the bottle "protects against....corrosion of copper or bronze bushings"

Have fun, I'll just continue to put available gear oil in the old transmissions and drive them.

 

"The main difference between GL-4 and GL-5 gear oils is the amount of EP additives. Sulphur/Phosphorus containing products are used as EP-additive. This additive has the purpose to prevent the occurrence of micro-welds on the gear flanks at the local high temperatures which prevail in EP cir***stances (temperatures well in excess of 800℃!) GL-5 has roughly twice the amount of EP additives compared to GL-4, which is why it is often used in high-pressure cir***stances such as in a front axle and rear axle differential.

Sulphur/Phosphorus additives however have an unfavourable property: they can react aggressively towards bronze and copper. This can be disastrous for the synchromesh rings of a gearbox. Therefore it is not recommended to use GL-5 in a gearbox unless the manufacturer allows this."

"They make GL4 gear oils with enough EP additives to protect spur and helical gears in manual transmissions. A GL4 will maintain the necessary balance of viscosity, detergency, and corrosion protection.

This type of oil is perfect for vehicle gear applications with high levels of yellow metals. An API GL5 gear oil has higher levels of active sulfur phosphorous, which will corrode yellow metals."

"Can GL-5 gear oil be used in an application where manual transmission fluid is recommended?"

The American Petroleum Ins***ute (API) GL rating system is intended for gear oil specifications. While a manual transmission does in fact have gears, it may also contain other components such as synchronizers. The gears and synchronizers have seemingly conflicting requirements. In general, the higher the GL rating, the higher the extreme pressure (EP) protection provided. This is great for reliability and wear reduction in hardened gear sets, but it can spell disaster for synchronizers.

EP additives are often made of a sulfur/phosphorus compound that will adhere to metal surfaces through polar attraction. Once they have coated a metal surface, these additives need only to be introduced to heat and/or pressure (from a collapsing lubricant film) to spring into action and start doing their job. In a hardened gear set, this adds a great deal of wear protection as well as life and reliability to the component.

However, because of the mechanism in which these EP additives work, when they are introduced to softer yellow metals, the results can be disastrous. They attach in the same manner (metal-wetting polar attraction), and when heat and/or pressure is introduced, the additives will chemically attack the softer yellow metals. This aggressive attack can prematurely wear out synchronizers.

GL-4 products typically use about half the sulfur/phosphorus additives of their GL-5 counterparts. This means they provide less protection for the gear set but do not damage synchronizers quite as severely. When a GL-5 gear oil is used in a manual transmission that contains synchronizers, you can expect to find two to four times as much copper in the used oil ****ysis report in comparison to a GL-4 oil. Eventually, the synchronizers will wear to the point that they no longer make contact with the other half of the cone, bottoming out before stopping the opposing gear.

So while an API GL-5 gear oil can be utilized in an application where manual transmission fluid is recommended, there will be a tradeoff. You can anticipate excellent protection for the gears but also a reduction in synchronizer life if these components are made of softer material."

But hey, you do you. Have your own science.

 

I hear about all these disasters that will happen with synchro rings, but no one has one that was damaged by GL-5.

I just think that's kind of strange. I see lots of pictures of other failed parts on the internets, but none of synchro rings.

It's almost like there's a tin foil hat conspiracy.

 

When you eventually prove yourself wrong, will you actually admit it?

 

Hell, it would be worth it to have the ONLY picture of a gear oil failed synchro ring on the while world wide webs!

but it won't happen....because it's not a real problem with old transmissions. Either that, or I'll be dead long before the failure occurs.

 

Hello Andrew DeLong.

 

The beautiful thing about science (specifically chemistry) is that it does not care what anyone's opinion about it is.

It is what it is, and it always be exactly that.

 

So after reading the back and forth, can you please explain this from Valvoline # 831 and many other gear oils ?

 

Its a good thing the scientific community of the day were proven wrong about the earth being flat , otherwise where would we be ?
Nothing in this world , science included, is infallible .

 

Nope.

But you might find that there are many different oils that meet the GL-5 spec, and most of them produced today do not have active sulfur. And some synthetic GL-5 fluids might be too "slippery" to be recommended for use in modern synchromesh transmissions. You'll also find some that say they are safe for use with br***.

Until someone shows me a synchro ring that was eaten up by the GL-5 gear oil I can buy at the local store, I'll continue to use it in my old cars with manual transmissions.

There are so many things we can worry about....some of them are worth worrying about, some are not. This one seems to me to fit in the "not" category. If you put a more modern transmission in an old car, you probably want to stick to the recommended lube for it. And that means probably something besides gear oil. Newer cars have been using lighter oils in manual transmissions for decades. But hey, this is the HAMB, and we're supposed to be talking about old stuff, and old stuff has always been a lot more forgiving about this stuff.

 

I wonder if the real culprit causing failure was a result of the alloy of the rings .
I’m sure there must be some wear,,,,,,,but is it really a problem in older transmissions with older synchros ?
Maybe in later models,,,or later replacements,,,,,the quality is different from the older br*** ?
Maybe the bean counter’s decided to make a new and improved ring with less of a certain ingredient ?
Kind of like making oil with less zinc and then wondering if it is causing the engine to wear too quickly .

Tommy

 

When I needed oil for my M20 a few years ago, I found that GL4 was hard to find locally. Most everything was a GL4/GL5 mash-up of some sort. I finally found some Richmond GL4 at a speed shop.

 

"Non synchronized manual transmissions" is the key term in that verbage.

No synchros means no synchros to erode.

 

My point in my post above, is that meeting the standard "GL-5" is not synonymous with "high active sulfur content".

There are several other things you need to look at about a particular oil you have in mind, and most of them are not listed on the bottle in a way that you can make a fully informed decision.

If the bottle does list that it's not suitable for synchromesh, there might be a reason other than the sulfur content. And if the bottle does list that it's safe for use with br*** components, then it's very likely that it does not have a problematic sulfur content.

Think about it, don't just knee-jerk

 

Essentially marketing a GL-5 gear oil as multi-use GL-4/GL-5 is very misleading by the oil companies. Here's a link to API standards
Microsoft Word - 1560-Update-in-New-Format-07-15-2013 (api.org)

 

Gimpy is right about this. The car OEM's along with lubricant and additive companies have done extensive testing and they have definitely found corrosion of yellow metals due to high EP additive content, and that is why the recommendation is to not use GL-5 spec gear oils in transmissions with synchros or other br***/bronze components, and why GL-4 continues to be a current specification, and GL-4 oils are available (as are GL-1 if you really want them). However, lubricant companies have worked with their formulations, specifically using deactivators, to reduce the corrosion effect of some GL-5 oils. Those oils will be safer in a synchronized manual shift trans, but they really are not intended for that application. GL-5 spec was developed for hypoid differentials, period. The development of hypoid differentials called for a gear oil with more aggressive EP performance due to the extreme sliding wear of a hypoid gear set, that is what GL-5 was designed and intended for, not for transmissions. GL-4 oils are available, why not use them?

The usual lubricant for manual shift truck transmissions has been SAE 50 grade motor oil for decades (until the modern auto-shift manuals became more common, which have their own specific lubricants). You could safely run 50 grade engine oil in an old manual shift transmission in a car as well; if the viscosity is too heavy shifting will be difficult when cold, in that case drop the viscosity down to an SAE 40 or 30 even, depending on how cold the ambient temps are where you live. The anti-wear additives in engine oil are sufficient to protect the gears in a transmission without causing corrosion of yellow metals. Even better are Caterpillar TO-4 spec oils available from any Cat dealership anywhere in the world, as well as most any other heavy equipment dealership because many (most?) other brands of equipment also use that same specification for their equipment, it's very common. And every major lubricant company has their version of it, it's one of the most common oils in existence. There are a million Caterpillar and other brands of equipment running TO-4 spec oils in transmissions and differentials and final drive/planetaries all over the world. They protect the gears and do not cause corrosion of yellow metals.

 

Awesome post! Thanks for sharing.

 

They 're not readily available whenever I go shopping. Sometimes I can find something called "synchromesh fluid", but it doesn't seem to be the same thing--it's a light oil.

Seriously, go shopping for GL-4 gear oil, see what you find. I mean at actual stores, not the internets.

Thanks for the explanation.

 

Thanks for posting that. I would never have noticed the recommendation was only for 'non-synchronized' transmissions just reading the bottle. Blown up on my screen there it is!

Edit: I'm using an A833, overdrive version in my 56 pickup build. I had an 'normal' 833 in a '65 Dart many years ago. One of the strange, to me at least, things was that the recommended lube was ATF. That is what I'm planning on in my latest one, if I ever finish. Often have wondered why that specific manual trans used ATF and others didn't.