The Ford Barn

[email protected] · 09-16-2023, 08:02 AM

600w oil is recommended. I believe that was the oil rating in 1927-30 that really matches 140w to 250w of today's oil. Is that accurate?

The Master Cylinder · 09-16-2023, 08:03 AM

Quote:

Originally Posted by [email protected]

600w oil is recommended. I believe that was the oil rating in 1927-30 that really matches 140w to 250w of today's oil. Is that accurate?

Yes

mcgarrett · 09-16-2023, 09:07 AM

Use 85-140 GL4 gear lube for the trans & rear axle.

oldspert · 09-16-2023, 09:12 AM

Quote:

Originally Posted by mcgarrett

Use 85-140 GL4 gear lube for the trans & rear axle.

I have two pints of GL-5, can I use that? Stock transmission and rear.

mcgarrett · 09-16-2023, 09:16 AM

oldspert,
The only problem with GL5 is that it has additives that are harmful to yellow metals. The reverse idler gear runs on a bronze bushing. Might eat it up over time.

Bob Bidonde · 09-16-2023, 09:18 AM

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Yes, you can use GL5 in a stock Model "A" transmission and differential.

[email protected] · 09-16-2023, 01:16 PM

Anyone use Amsoil severe gear 250w? I use that in my Harley.

nkaminar · 09-16-2023, 01:52 PM

Modern gear oils have an additive that binds to the steel, and yes brass. The additive wears instead of the steel, or brass. G5 has twice as much of the additive than G4. G4 is used in transmissions with brass synchro rings and G5 for transmissions without the brass synchro rings. The additive in the G5 actually protects the brass too much and chunks of the synchro rings break off. The brass bearing in the Model A transmission is not under the impact loads of the synchro rings in a synchro transmission so the G5 gear lube can be used in the Model A transmission.

85W-140 is recommended by Mitchell who make the synchro transmission and the overdrive for the Model A. Modern gear oils will protect the parts in the Model A transmission (and rear end) better than the "600" oil available today. However, you have to shift a little slower or use a double clutch as the oil is not as viscus.

8EL · 09-17-2023, 06:50 AM

I used the 85W-140 in the transmission, it worked well, except while sitting for periods of time it would leak out around the cluster gear shaft. There is no seal between the shaft and the case as originally designed. Switching to the 600W oil ended this problem. I always double clutch when shifting, if not, the designation "crunch boxes" Henry gave the sliding gear transmission in defense of his Model T becomes apparent. In cold weather, the 600W is to thick to allow the meshing advantage of double clutching however. After a couple of miles it has thinned enough to shift normally....

I am thinking the advantage gotten over this old oil formulation with new extreme pressure (EP) compounds would be beneficial for use in the differential. I am intending to use it in the new differential overhaul as the problem with it in the transmission does not seem to be apparent.

09-16-2023, 08:02 AM	#1
[email protected] Junior Member Join Date: Sep 2023 Location: Chicago, IL Posts: 14	Tranmission oil 600w oil is recommended. I believe that was the oil rating in 1927-30 that really matches 140w to 250w of today's oil. Is that accurate?

09-16-2023, 09:07 AM	#3
mcgarrett Senior Member Join Date: Dec 2013 Location: Waxahachie, Texas Posts: 956	Re: Tranmission oil Use 85-140 GL4 gear lube for the trans & rear axle.

09-16-2023, 09:16 AM	#5
mcgarrett Senior Member Join Date: Dec 2013 Location: Waxahachie, Texas Posts: 956	Re: Tranmission oil oldspert, The only problem with GL5 is that it has additives that are harmful to yellow metals. The reverse idler gear runs on a bronze bushing. Might eat it up over time.

09-16-2023, 09:18 AM	#6
Bob Bidonde Senior Member Join Date: May 2010 Location: Long Island, NY Posts: 3,495	Re: Tranmission oil Sponsored Links (Register now to hide all advertisements) Yes, you can use GL5 in a stock Model "A" transmission and differential. __________________ Bob Bidonde

09-16-2023, 01:16 PM	#7
[email protected] Junior Member Join Date: Sep 2023 Location: Chicago, IL Posts: 14	Re: Tranmission oil Anyone use Amsoil severe gear 250w? I use that in my Harley.

09-16-2023, 01:52 PM	#8
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,944	Re: Tranmission oil Modern gear oils have an additive that binds to the steel, and yes brass. The additive wears instead of the steel, or brass. G5 has twice as much of the additive than G4. G4 is used in transmissions with brass synchro rings and G5 for transmissions without the brass synchro rings. The additive in the G5 actually protects the brass too much and chunks of the synchro rings break off. The brass bearing in the Model A transmission is not under the impact loads of the synchro rings in a synchro transmission so the G5 gear lube can be used in the Model A transmission. 85W-140 is recommended by Mitchell who make the synchro transmission and the overdrive for the Model A. Modern gear oils will protect the parts in the Model A transmission (and rear end) better than the "600" oil available today. However, you have to shift a little slower or use a double clutch as the oil is not as viscus. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

09-17-2023, 06:50 AM	#9
8EL Senior Member Join Date: Jul 2023 Posts: 235	Re: Tranmission oil I used the 85W-140 in the transmission, it worked well, except while sitting for periods of time it would leak out around the cluster gear shaft. There is no seal between the shaft and the case as originally designed. Switching to the 600W oil ended this problem. I always double clutch when shifting, if not, the designation "crunch boxes" Henry gave the sliding gear transmission in defense of his Model T becomes apparent. In cold weather, the 600W is to thick to allow the meshing advantage of double clutching however. After a couple of miles it has thinned enough to shift normally.... I am thinking the advantage gotten over this old oil formulation with new extreme pressure (EP) compounds would be beneficial for use in the differential. I am intending to use it in the new differential overhaul as the problem with it in the transmission does not seem to be apparent.