GL-5 no no

[Old Henry]

Maybe I am the last one to learn this but I just learned not to use GL-5 gear oil in our old transmissions as it has additives that can cause more rapid deterioration of the soft metals in them. Here's a very definitive treatise on the subject that is very educational and insightful: http://www.widman.biz/uploads/Transaxle_oil.pdf

[JSeery]

Not sure how you have missed it as GL5 vs GL4 or EP has been one of the more frequent topics on the Barn for years.

[TonyM]

Yep, discussed many times on the forum.

As recently as a couple weeks ago.



https://www.fordbarn.com/forum/showt...ight=Trans+oil

[Old Henry]

Sorry I brought it up. I'll see if I can get this thread deleted.

[Old Henry]

Originally Posted by Old Henry

Sorry I brought it up. I'll see if I can get this thread deleted.

On second thought, maybe not. It could be that at least one of the 147 that have read this thread so far had missed or ignored this information as I had and might benefit by it.

[petehoovie]

Sponsored Links (Register now to hide all advertisements)

Thanks for posting that link, Craig....

[JSeery]

Don't think it hurts to keep the topic fresh, new folks here every day!

[Joe Immler]

No apology needed Henry. Please don't delete. I printed the info and it is in my hard copy info.

[TonyM]

Originally Posted by Old Henry

On second thought, maybe not. It could be that at least one of the 147 that have read this thread so far had missed or ignored this information as I had and might benefit by it.

Yes, leave it up.

[stangblue]

Thanks for posting still learning (try to learn something everyday, remembering is another topic) . Thanks!
I digress,Think we have it tough!
The Covered Wagon - Oregon Pioneers
www.oregonpioneers.com/wagon.htm
The covered wagon used to cross the plains to the west was a smaller, ... Waterproofed with paint or linseed oil, the top was of heavy duty canvas, ... Hanging from the rear axle was the grease bucket, filled with a mixture of animal fat and tar. Used for greasing the axles and hitch.

[jimTN]

I have read all of the above and links. Now, someone please tell me what brand, type and location to purchase commonly the correct trans and rear end lube.

[Old Henry]

Originally Posted by jimTN

I have read all of the above and links. Now, someone please tell me what brand, type and location to purchase commonly the correct trans and rear end lube.

GL-5 is not bad for rear end as there is no yellow metal there so any off the shelf gear lube will do. I use Valvoline 85W-140 from AutoZone or O'Reilly's for year 'round use.

NAPA carries Sta-Lube 80W-90 GL-4 on their shelves (in gallons only) for the transmission.

[19Fordy]

Here is the least expensive place to buy Stalube Gear Oil 140SAE GL-4.
$9.83 per gallon - even when you add shipping cost. I just received the gallon I ordered 5 days ago. Cost was as follows:
Gear Oil $9.83
Handling Charge $1.95
Tax $1.61
TOTAL $28.24
https://www.finditparts.com/products...rc-ind-sl24238

[jimTN]

I bought a 2gal jug of 90wt from Rural King today, it did not reference gl4 or 5 and was $19.00. Will have to dig deeper to determine what is in it as it was not listed like normal oil jugs but did say extreme pressure lub.

[JSeery]

Originally Posted by jimTN

I bought a 2gal jug of 90wt from Rural King today, it did not reference gl4 or 5 and was $19.00. Will have to dig deeper to determine what is in it as it was not listed like normal oil jugs but did say extreme pressure lub.

It's most likely GL-5. GL-5 is common, GL-4 is not common. GL-5 is high EP & GL-4 is much lower EP.

[edhd58]

I am glad this is being covered again, I need to go look at what i put in my trans when I swapped gears. I think i looked for GL-4 but now i'm not sure.

[klicker]

I picked up gl- 4 the other day. Got it home and realized it is 90wt. Will this be ok in trans? Reading recently, seems like it will just leak out faster...

[19Fordy]

The 40 owners manual says to use SAE 90 in winter and sae 140 in summer.
Not sure how cold winter gets in OR but I would think 140SAE would be safe to use all year round.

[jimTN]

Those of us that have Columbia and Ruckstell two speed rear ends are concerned about brass because both types of rear ends have brass in them.

[Step-down]

So GL 4 80-90 in Columbia

[Ford Freak]

How about this : http://www.autozone.com/greases-and-...oz-/693859_0_0

[Old Henry]

Originally Posted by Ford Freak

How about this : http://www.autozone.com/greases-and-...oz-/693859_0_0

If you don't mind GL-5 it's fine. It is GL-5 lubricant. It's like what I use in my stock differential.

[jimTN]

The Rural King 90wt says specifically for older vehicles with manual transmissions.

[JSeery]

Lucas SAE 85W-140 gear oil

Standards:
Exceeds All GL Classifications, API GL-4, API GL-5, API MT-1, SAE J2360 MIL-PRF-2105E, MACK GO-J, PG-2 Limited Slip

I wouldn't use it, but it is your decision!

[JSeery]

Originally Posted by jimTN

The Rural King 90wt says specifically for older vehicles with manual transmissions.

Almost all gear lubricants say something similar to that and are backwards compatible with GL-4 requirements. That is a different issue than "yellow" metal safe. You have to check the actual ratings. Some have even reported problems with GL-5 products that claim to be "yellow" metal safe, so why take the chance? A GL-5 rating is not required in a manual transmission so why use it?

"GL-5 is not necessarily backward-compatible in synchro-mesh transmissions which are designed for a GL-4 oil: GL-5 has a lower coefficient of friction due to the higher concentration of EP additives over GL-4, and thus synchros can not engage as effectively. Also, transmissions which explicitly call for GL-4 oil may have been designed around this lower concentration of EP additives and thus may contain yellow metal parts which GL-5 will corrode."

"Gearbox oils are classified by the American Petroleum Institute using GL ratings. The higher GL-rating the more pressure can be sustained without any metal-to-metal contact taking place between transmission components. Separate differential usually have higher pressure between metal parts than gearboxes and therefore need higher GL-rating. For example, most modern gearboxes require a GL-4 oil, and separate differentials (where fitted) require a GL-5 oil."

"API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D (formerly MIL-L-2015C), MIL-PRF-2105E and SAE J2360 satisfy the requirements of the API GL-5 service designation."

[flatford8]

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"Backwards compatible".... I've read where you've used this term in posts on this topic
(GL-5). I don't get what you mean by this....Mark

[JSeery]

That is the term gear lube suppliers use. It means a lubracation specified GL-5 meets or exceeds GL-4 specifications. This is confusing because just because it meets and exceeds lubracation requirements does not mean it is safe for "yellow" metals. At one time in the past GL-4 was specified for rear axles for example. When GL-5 became available it was listed as also acceptable to use in rear axles originally specifying GL-4 (backward compatible). BUT, this applies ONLY to it's lubracation qualities, NOT to compatibility with 'yellow' metal (synros, bushings, etc.)

[50fordcoupeman]

I was looking at a local auto parts house for GL-4. The parts person said that GL-5 was ok to use in my synchro tranny. I showed him on one of his GL-5 bottles it said and I quote " Not for use in synchromesh transmissions". He said oh I didn't know that. Pretty clear to me....................

[V8COOPMAN]

Originally Posted by 50fordcoupeman

I was looking at a local auto parts house for GL-4. The parts person said that GL-5 was ok to use in my synchro tranny. I showed him on one of his GL-5 bottles it said and I quote " Not for use in synchromesh transmissions". He said oh I didn't know that. Pretty clear to me....................

I'm sure he'd be "more qualified" if he got a raise to $15/hr. Unfortunately, our world is full of 'em! DD

[flatford8]

Originally Posted by JSeery

That is the term gear lube suppliers use. It means a lubracation specified GL-5 meets or exceeds GL-4 specifications. This is confusing because just because it meets and exceeds lubracation requirements does not mean it is safe for "yellow" metals. At one time in the past GL-4 was specified for rear axles for example. When GL-5 became available it was listed as also acceptable to use in rear axles originally specifying GL-4 (backward compatible). BUT, this applies ONLY to it's lubracation qualities, NOT to compatibility with 'yellow' metal (synros, bushings, etc.)

Ok..... got it.....Thank you......Mark

[Ford Freak]

Originally Posted by JSeery

Lucas SAE 85W-140 gear oil

Standards:
Exceeds All GL Classifications, API GL-4, API GL-5, API MT-1, SAE J2360 MIL-PRF-2105E, MACK GO-J, PG-2 Limited Slip

I wouldn't use it, but it is your decision!

I was just curious . I've got some Sta-Lube GL-4 140wt. that I will use .

[JSeery]

Originally Posted by 50fordcoupeman

I was looking at a local auto parts house for GL-4. The parts person said that GL-5 was ok to use in my synchro tranny. I showed him on one of his GL-5 bottles it said and I quote " Not for use in synchromesh transmissions". He said oh I didn't know that. Pretty clear to me....................

There are several reports of the supplier tech folks giving the same type of answers! I think it's the "yellow" metal confusion, because all of the GL-5 lubes say they are fine for GL-4 applications from a lubrication prospective. Another problem is it is not an instant problem type of deal, it takes time to show up. The EP additive bonds to the yellow metals and then peals off at a microscopic level. So over time it peels off the surface one layer at a time.

[Chisel]

Originally Posted by JSeery

There are several reports of the supplier tech folks giving the same type of answers! I think it's the "yellow" metal confusion, because all of the GL-5 lubes say they are fine for GL-4 applications from a lubrication prospective. Another problem is it is not an instant problem type of deal, it takes time to show up. The EP additive bonds to the yellow metals and then peals off at a microscopic level. So over time it peels off the surface one layer at a time.

As stated above-- so over time it peels off the surface one layer at a time. So what is the definition of over time? 1 year 10 years 100 years? Has anyone had a failure of their synchro rings using GL-5 that says it's safe for yellow metals?
I have been using it for about 3 years so far with a transmission that has a little over 50,000 miles on it and it made shifting easier and the transmission quieter after the change.

[JSeery]

It depends on the pressure on the part and the number of cycles. If you like the GL-5 use it, the information is for the folks who care about these issues. No matter what the topic is someone has always been doing it for 50 years with no problem. Just seems to be the way it is. You would think the transmission manufactures telling you not to use it would be enough.

An added note: There are some newer GL-5 lubes that claim to be safe. It is not the GL-5 rating that is the issue, it is the EP additive. If some suppliers are using different additives that would make a difference.

[1937pickup]

Old Henry,
Have you asked Mac VanPelt what he recommends using in his rebuilt transmission? I think he would be the definitive source on this information.

[Old Henry]

Originally Posted by 1937pickup

Old Henry,
Have you asked Mac VanPelt what he recommends using in his rebuilt transmission? I think he would be the definitive source on this information.

I didn't ask him, neither did he volunteer a recommendation. Neither did he say there was any excessive wear on any of my "yellow metal" since I replaced them two years and 33,000 miles ago. I've had my transmission opened up for rebuild/inspection 4 times in the last 10 years, 100,000 miles, and have never seen any excessive wear of "yellow metal". That's using GL-5 lubricant. So, although the theory of GL-5 causing excessive wear of "yellow metal" parts probably makes sense, in actual practice I doubt it's enough for anyone to actually notice, especially anyone just driving their cars a few miles a year. Even so, since I'm driving mine 10,000 miles a year, I'm doing anything and everything anyone suggests to make my transmission last longer. May not make a difference but, then, again, maybe it will. It's worth the effort "just in case."

[1937pickup]

Old Henry, I was re-reading your previous post regarding Mac's rebuild and how happy you are with the service. I came to a post by a Pete VS who said he purchased some tranny parts from Mac and had him send him some transmission oil. Mac sent him GL-4. After reading this I will be changing my transmission from GL-5 MT to GL-4.

[GB SISSON]

I have been reading this with interest. I just last week put GL4 85-90 in my T9 or is it T8 four speed. I would have liked to use a heavier GL4 like 140w, but napa didn't have it on the shelf. While not a synchro, does the crashbox have yellow metal?

[jake197000]

on any newer vehicles we work on we try to use what the manufacturer recommends but on older cars we use GL-5 in pretty much everthinghave never had a problem that i know of in 40 years.im sure there is valitity in the debate but i think its overblown.a race car or the like maybe but i dont think its a big deal on an old thre or four speed.this is a general statement.i dont worry about it much

[Ron Pilger]

This discussion has been valuable. While some posters view the information being conveyed as redundant "old news", i am thrilled to get new professional opinion and amateur perspective, alike.

I have worked in the advertising field for the past forty years. The original post and the discussion which has followed reminds me of timeless training in my career:
The first time people look at any given ad, they don't even see it.
The seventh time, they see the message they start to get a little irritated with it.
By the seventeenth time of seeing that lousy ad, they make a note to buy the product.
By the twentieth time a prospect sees the ad, they go buy the product that will solve their need.

With this in mind, thanks for reopening good discussion on this age-old topic. And for sharing your individual thoughts. It is clear that many people, even veterans in this stupid hobby, are in some cases just getting exposed to this perplexing oil dilemma. I'm especially pleased that the original post didn't get taken down as quickly as it went up.

[19Fordy]

Many outboard stern drive marine engines use GL-4 gear oil in their lower unit. It's suppose to be changed every season due to the harsh underwater environment. But, cars wouldn't have the problem.
I wonder if it would be ok for our old Fords. It does not attack yellow metals.
Any thoughts?
http://www.amsoil.com/shop/by-produc...ine-gear-lube/

[jimvette59]

I think it's the non foaming properties that matters in both outboard motors and transmissions. JMHO

[50fordcoupeman]

I change the lower unit oil in my Volvo-Penta every season regardless of hours. Manual says to use "30wt engine oil". But in my avatar synchro tranny I use GL-4. If there is ANY question, why take the chance with GL-5? It certainly isn't cost..........