The Ford Barn

Hoop · 05-16-2011, 11:30 AM

API classification subdivides all transmission oils into 6 classes:

API GL-1, oils for light conditions. They consist of base oils without additives. Sometimes they contain small amounts of antioxidizing additives, corrosion inhibitors, depresants and antifoam additives. API GL-1 oils are designed for spiral-bevel, worm gears and manual transmissions without synchronizers in trucks and farming machines
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API GL-2, oils for moderate conditions. They contain antiwear additives and are designed for worm gears. Recommended for proper lubrication of tractor and farming machine transmissions.

API GL-3, oils for moderate conditions. Contain up to 2.7% antiwear additives. Designed for lubricating bevel and other gears of truck transmissions. Not recommended for hypoid gears.

API GL-4, oils for various conditions - light to heavy. They contain up to 4.0% effective antiscuffing additives. Designed for bevel and hypoid gears which have small displacement of axes, the gearboxes of trucks, and axle units. Recommended for non-synchronized gearboxes of US trucks, tractors and buses and for main and other gears of all vehicles. These oils are basic for synchronized gearboxes, especially in Europe.

API GL-5, oils for severe conditions. They contain up to 6.5% effective antiscuffing additives. The general application of oils in this class are for hypoid gears having significant displacement of axes. They are recommended as universal oils to all other units of mechanical transmission (except gearboxes). Oils in this class, which have special approval of vehicle manufacturers, can be used in synchronized manual gearboxes only. API GL-5 oils can be used in limited slip differentials if they correspond to the requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS.

API GL-6, oils for very heavy conditions (high speeds of sliding and significant shock loadings). They contain up to 10% high performance antiscuffing additives. They are designed for hypoid gears with significant displacement of axes. Class API GL-6 is not applied any more as it is considered that class API GL-5 well enough meets the most severe requirements.

Don · 05-16-2011, 07:11 PM

Found the last gallon of gl -1 140 around here, went to an old auto parts store that has been around sence i was a kid. He says sure i got one left. Don p

lotsagas4u · 05-28-2011, 09:31 PM

I replaced my transmission oil today with Napa GL-1 80-90 wt /mineral/gear oil, drove it around town some, transmission grinds easier than before, lots of double clutching, not sure which transmission I have, 3 speed behind an 8BA. Seemed like it shifted better with Coastal 80/90 GL4 or 5. Any thoughts?

05-16-2011, 11:30 AM	#21
Hoop Senior Member Join Date: May 2010 Location: Jacksonville FL Posts: 1,137	Re: Cant find gear lube gl-1. Dows gl-5 take its place? API classification subdivides all transmission oils into 6 classes: API GL-1, oils for light conditions. They consist of base oils without additives. Sometimes they contain small amounts of antioxidizing additives, corrosion inhibitors, depresants and antifoam additives. API GL-1 oils are designed for spiral-bevel, worm gears and manual transmissions without synchronizers in trucks and farming machines . API GL-2, oils for moderate conditions. They contain antiwear additives and are designed for worm gears. Recommended for proper lubrication of tractor and farming machine transmissions. API GL-3, oils for moderate conditions. Contain up to 2.7% antiwear additives. Designed for lubricating bevel and other gears of truck transmissions. Not recommended for hypoid gears. API GL-4, oils for various conditions - light to heavy. They contain up to 4.0% effective antiscuffing additives. Designed for bevel and hypoid gears which have small displacement of axes, the gearboxes of trucks, and axle units. Recommended for non-synchronized gearboxes of US trucks, tractors and buses and for main and other gears of all vehicles. These oils are basic for synchronized gearboxes, especially in Europe. API GL-5, oils for severe conditions. They contain up to 6.5% effective antiscuffing additives. The general application of oils in this class are for hypoid gears having significant displacement of axes. They are recommended as universal oils to all other units of mechanical transmission (except gearboxes). Oils in this class, which have special approval of vehicle manufacturers, can be used in synchronized manual gearboxes only. API GL-5 oils can be used in limited slip differentials if they correspond to the requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS. API GL-6, oils for very heavy conditions (high speeds of sliding and significant shock loadings). They contain up to 10% high performance antiscuffing additives. They are designed for hypoid gears with significant displacement of axes. Class API GL-6 is not applied any more as it is considered that class API GL-5 well enough meets the most severe requirements. __________________ "Remember that when it comes to intelligence, half of all of us are below average."

05-16-2011, 07:11 PM	#22
Don Senior Member Join Date: May 2010 Location: Ashland KY Posts: 1,159	Re: Cant find gear lube gl-1. Dows gl-5 take its place? Found the last gallon of gl -1 140 around here, went to an old auto parts store that has been around sence i was a kid. He says sure i got one left. Don p __________________ DON P

05-28-2011, 09:31 PM	#23
lotsagas4u Senior Member Join Date: Apr 2011 Location: Plainview, Texas Posts: 779	Re: Cant find gear lube gl-1. Dows gl-5 take its place? I replaced my transmission oil today with Napa GL-1 80-90 wt /mineral/gear oil, drove it around town some, transmission grinds easier than before, lots of double clutching, not sure which transmission I have, 3 speed behind an 8BA. Seemed like it shifted better with Coastal 80/90 GL4 or 5. Any thoughts?