Reference: Manual Transmission Oil

[Wayne Hingley]

Some recent posts on transmission lubricants in Jordan's C15A thread http://www.mapleleafup.net/forums/sh...t=3643&page=13 caught my attention. Specifically the posts of Rob, Robert and Lynn (in around post #371), related to oil compatibility with brass (soft yellow metal) components.

From some training on oils and lubricants that I had about 8 years ago, I specifically remembered that soft yellow metals can be severely damaged by certain oil additives. Certain extreme pressure (EP) additives are not compatible with these soft yellow metals, and knowing this along with seeing the posts mentioned above, I was immediately alarmed. In recent years, EP has become a common additive to many of the newer gear oils for modern vehicles, as the EP additive is used to cushion the contact surfaces of gears to reduce wear, and give a smooth feel when shifting and engaging. Im assuming that modern manual transmissions do not have brass components, so the use of EP has become very standard, other than some exceptions such as mentioned by Rob with his Dodge transmission.

The Dana/Spicer jeep transmissions do have several brass components, and the use of common EP oils will have a negative effect as mentioned by Robert and Lynn.

Below are a couple of slides about EP additives from my training package.

[Wayne Hingley]

Having recently changed the transmission lubricant in my M38A1, I realized I hadn't considered whether my oil had EP additive in it or not, as I wasn't aware most newer oils (GL 4 & 5 certifications) contained EP. Its not well identified on some containers, so you need to look at the specifications to see what additives are in the oil and what compatibility notes are outlined by the manufacturer.

Sure enough the oil I used contained an EP additive. I have now drained my transmission and transfer case (along with my steering box and PTO/winch), and flushed them out, and refilled with a non-EP yellow metal compatible oil.

My jeep had less than 100 miles on the EP oil, and I already had signs of breakdown of some brass components (see photos below). The first photo is the oil that I drained, and the second is the "flush". You can see the brass on the bottom of the drain pan.

I hope others will check their systems, and avoid the types of failures noted by Robert and Lynn.

My transmission is still working perfectly, so I think I was lucky to take action before too much damage was caused.

[rob love]

Thanks for the posts Wayne.

I have been trying to do a little research into the gear oil question, and it would seem that if the GL5 has an MT1 designation, it may be OK for the yellow metals.

I also may start a program of changing the gear oils in most of the museum's vehicles, as well as my own. Pretty sure I have been using off the shelf 80W90 in most of my older transmissions, including my Jeep.

Perhaps we can post what oils are available at Cdn tire/NAPA/Walmart that are reasonably priced and fully compatible.

Barry mentioned using straight weight 50 motor oil in the transmissions. On one forum I looked at, they mentioned even going to as low as 30W oil and having satisfactory results.

[Wayne Hingley]

Rob, I have a few documents in my oil resources folder that I still need to go through. Below is one excerpt from a 215 page Petro Can document that generally outlines the API Classifications. I have another similar manual from Shell that I haven't looked at yet. The correct lubes are out there, but the ones we want are more "specialized" than in the past. I will post any that I come up with too.

The second image (API descriptions) is from a Shell Lubricants Handbook.

Im not 100% sure, but it appears the API classes are more related to the application and type of service, and are independent of the additive package(s) that each manufacturer may include in each specific product.

[Wayne Hingley]

Below is an example of a product that specifically mentions being compatible with yellow metals...

[Jordan Baker]

Thanks Wayne, this subject is probably best on its own thread so as not to get lost in my restoration thread. Ill now be checking my Willys MB

[Wayne Hingley]

Originally Posted by Jordan Baker

Thanks Wayne, this subject is probably best on its own thread so as not to get lost in my restoration thread. Ill now be checking my Willys MB

Yes I thought we hijacked your thread enough, Jordan...

[Hanno Spoelstra]

Wayne, very good subject!

My first question is: do the CMP drive lines have brass/ bronze bushings? I was not aware of that.

Here is a list of modern replacement lubricants which Hendrik van Oorspronk published in one of the issues of Keep The Rolling magazine. I now wonder if the lubricants listed here are the correct ones?

Regards,
Hanno

Lubrication for Ford Canada CMP

Engine:
Original specification: Engine oil. Winter: SAE 10; Summer: SAE 30.
Modern replacement: Mineral 15W/40 oil or if the engine has been overhauled: semi-synthetic 10W/40 oil.

Gearbox / transfer case:
Original specification: Gear oil. Winter: SAE 110; Summer: SAE 140.
Modern replacement: Transmission oil 140 or 85W/140 with API specification GL4. Thickness SAE 110 is no longer available.

Front and rear axle:
Original specification: Extreme pressure Gear Oil. Winter: SAE 80; Summer: SAE 90, over 32º C: SAE 140
Modern replacement: 1st choice: hypoid oil GL5 80W/90, or if you have 1 oil for the gearbox and use the axes GL4 80W/90 or GL4 85W/140

Grease points and CV joints (stub axles):
Original specification: Wheel Bearing Lubricant
Modern replacement: Lithium EP 2 grease

Steering box:
Original specification: Gear oil
Modern replacement: Gearbox oil GL4; a good alternative is a 0 or 00 grease, this lubricates at least as well and it wheelhouse no longer leaks.

[Tony Smith]

In Australia, Penrite offers a good range of specialist oil products for older vehicles, both with and without EP additives, and with and without Zinc.

[rob love]

Originally Posted by Hanno Spoelstra

Wayne, very good subject!

My first question is: do the CMP drive lines have brass/ bronze bushings? I was not aware of that.

Here is a list of modern replacement lubricants which Hendrik van Oorspronk published in one of the issues of Keep The Rolling magazine. I now wonder if the lubricants listed here are the correct ones?

Regards,
Hanno

Lubrication for Ford Canada CMP

Engine:
Original specification: Engine oil. Winter: SAE 10; Summer: SAE 30.
Modern replacement: Mineral 15W/40 oil or if the engine has been overhauled: semi-synthetic 10W/40 oil.

Gearbox / transfer case:
Original specification: Gear oil. Winter: SAE 110; Summer: SAE 140.
Modern replacement: Transmission oil 140 or 85W/140 with API specification GL4. Thickness SAE 110 is no longer available.

Front and rear axle:
Original specification: Extreme pressure Gear Oil. Winter: SAE 80; Summer: SAE 90, over 32º C: SAE 140
Modern replacement: 1st choice: hypoid oil GL5 80W/90, or if you have 1 oil for the gearbox and use the axes GL4 80W/90 or GL4 85W/140

Grease points and CV joints (stub axles):
Original specification: Wheel Bearing Lubricant
Modern replacement: Lithium EP 2 grease

Steering box:
Original specification: Gear oil
Modern replacement: Gearbox oil GL4; a good alternative is a 0 or 00 grease, this lubricates at least as well and it wheelhouse no longer leaks.

Hanno
I believe there is a thrust pad in the Ford differentials that is bronze. And certainly the steering box is going to have brass bushing for the pitman shaft.

Re the Chev transmissions, if the transmission has been replaced with one of later production with synchros, then you are going to have brass synchro rings.

I don't think there is much for brass in the Ford tranny, although the thrust washers on the lower half may be. I'll have to check my transmission parts.

[Lauren Child]

Just to be clear, the old Hypoid 90 gear oil was required to be compatible with copper, where modern oils may not be.

It’s part of the specification in the Handbook of Service Lubricants March 1945.

As of the 1950s, Hypoid 90 or GO-90 becomes OEP-220 but is still required to have no delitirious effect on copper.

The spec for OEP 220 has apparently changed over time, and now says that it may not be suitable for use with copper alloys, even in a GL5 spec - https://www.dstan.mod.uk/StanMIS/Ind...945?seriesId=2

[leo tomaiolo]

on my 41 ford with the marmon herrington 4x4 i filled my drive line with modern GL-5 fluid. went out for a ride and the drive line was real noisy and the transfer case got real hot. checked the manual and it specified sae 140w GL-3. GL-3 is for mild extreme pressure. i was able to find it (Summit racing). the GL-3 lube made a huge difference in driveabilty. note the modern oil i originally used said it covered GL-3 but was EP. after looking in to it the modern oil did not have enough suspension (MEP vs EP) to stay in the void of the gears resulting in not enough oil cushion between the gears.

[Les Kovacs]

Hi Wayne & Rob.

Great post Wayne.....Rob sent me a similar explanation many months ago as I was looking for a suitable transmission/transfer case oil.

At the time I settled on Redline MT-90. It states that its....

•Safe for brass synchros, as it lacks the reactive sulfurs found in most GL-5 oils that cause damage
•Recommended for GL-1, GL-3 and GL-4 applications, as well as where most special synchromesh fluids are specified.
•Satisfies the gear oil viscosity requirements of 75W90, 80W90, 90 and motor oil viscosities of SAE 40, 10W40 and 15W40

Unfortunately its $25.00 CAD/liter as it is a synthetic.....but shift feel is fantastic.

if you have found a cheaper, safe & local (Canadian sourced) alternative please let me know as its not stated in your post.

Regards to both...

lesk

[Alex van de Wetering]

EP doesn't necessarily mean it's not compatible with yellow metals! I recently bought "Penrite Mild EP Gear oil" for my Chev steering box. It's safe to use with yellow metals. The C8 steering box has a washer and a bushing in brass. The box still leaks though.....so I am now also looking at the 0 or 00 grease, which is what is used in hydraulic systems on trucks here.....I wonder, is it safe for use with yellow metals?

https://www.penriteoil.com.au/produc...ar-oil-sae-110

Alex

[Wayne Hingley]

Originally Posted by Alex van de Wetering

EP doesn't necessarily mean it's not compatible with yellow metals!

You are correct Alex. There are several specialty oils with EP additive packs that are yellow metal "friendly".

Les: I have decided to use Royal Purple MaxGear 75w90. It is available through Canadian Tire.

Below is some info from their website:
Max Gear is recommended for use in truck and automotive front or rear differentials, manual transmissions and lower gear units of marine engines that specify use of an API GL-5 or GL-4 fluid. It is non-corrosive to soft yellow metals (brass, bronze, copper, etc.) and synchronizer safe.

[Les Kovacs]

Thanks Wayne....its now a matter of price....if the Royal Purple product is cheaper than the Redline MT90 I will switch.

Regards,

lesk

[Jacques Reed]

As I am about to swap the gears from one transmission case to another on my Ford F15-A I thought it would be a good time to revisit the type of gear oil to use.
After reading this thread I started hunting around on the net for more info. A lot of info that I read about EP additives to gear oil dealt with damage to bronze synchronizers in synchromesh transmissions or bronze worm gears.

In a Ford CMP truck with a non-synchro transmission my main concern however is possible deterioration caused by those additives to the reverse slider gear bronze bushing and the bronze thrust washers in the end gears in the differentials

Extreme pressure rating GL-4 gear oils have about half the quantity of buffered sulphur phosphate EP additives as GL-5 rated oil so is less harmful to yellow metal. As the rating indicates however, GL-4 Extreme pressure protection of gears is less than GL-5 rating.

The next question: Is GL-4 rated 80W-90 gear oil equivalent to, or even better, than the wartime SAE 90 gear oil as far as gear tooth protection goes? If so only GL-4 rated gear oil seems the obvious choice.

Ford gives a spec in their Special Pattern Vehicles manual as Ford spec MC-568A and call it “Extreme Pressure Gear Oil”. Haven’t been able to find a copy of it. It would probably be difficult to relate it to modern extreme pressure ratings anyway.

I have been using Castrol EPX 80W-90 in my CMP truck but it is GL-5 rated so it would have double the yellow metal damaging EP additive compared to a GL-4 gear oil. I found 3 suppliers of only GL-4 rated gear oils in Australia. Penrite, Hi-Tec, and Shell make them and market them here.

On the positive side, the reverse slider gear bushing seems fine even after being immersed in GL-5 oil for 10 years but then again I cannot see micron size damage! Hopefully ditto for the end gear thrust washers.

Any ideas on the subject gratefully received.

Have attached the link to the paper written by Richard Widman a Chevy Corvair enthusiast and a link to a Machinery Lubrication article on EP additives. Both are very informative on this subject.
https://www.widman.biz/uploads/Transaxle_oil.pdf
https://www.machinerylubrication.com...itives-effects