GL-4 Gear Lube
07-19-2005, 08:02 PM
#1
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2023 C2 of the Year Finalist - Unmodified
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GL-4 Gear Lube
I own an auto store and today a customer came in and wanted gear oil for his manual trans. He said the manual specified GL-4.
I only carried GL-5 and was under the assumption you could use it in a trans also.
So I called Pennzoil, I am a direct customer, and asked the tech over there. He said you should not use GL-5 in a trans with any "yellow metal"( brass syncros) because it has more additives than GL-4 and it would deteriorate the syncros over time and create problems.
Here is the spec sheet on the GL-4.
You learn something everyday.
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PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is specially formulated to meet the unique requirements of API GL-4 service in manual transmissions and transaxles of passenger cars, light trucks and SUV’s. PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is blended from select base stocks and additives that yield a lubricant of exacting quality. This product is compounded utilizing specialized extreme pressure chemistry that provides protection of gears and bearings without being corrosive to bronze components. It contains foam suppressants to prevent wear, which can be caused by lubricant foaming and aeration. Effective rust and corrosion inhibitors protect metal surfaces from the effects of water contamination from condensation and the operating environment. PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT resists the formation of varnish deposits on synchronizer components, thus assuring long, trouble-free operation.
PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 gives the full protection of an SAE 90 under hard driving conditions while providing the flow characteristics of SAE 80W that are necessary during cold weather start-ups. This offers maximum lubrication and gear protection over a wide temperature range.
APPLICATION
PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is designed for manual transmissions and transaxles of both American and import vehicles. It is formulated to be compatible with “yellow metals”, such as bronze, found in synchronizers and other transmission componenets.
BENEFITS
• Meets the performance requirements of API GL-4 Service
• Will not cause glazing of synchronizer components
• Excellent thermal stability
• Outstanding extreme pressure and antiwear protection
• Prevents rust and corrosion
• Inhibits foaming and aeration
I only carried GL-5 and was under the assumption you could use it in a trans also.
So I called Pennzoil, I am a direct customer, and asked the tech over there. He said you should not use GL-5 in a trans with any "yellow metal"( brass syncros) because it has more additives than GL-4 and it would deteriorate the syncros over time and create problems.
Here is the spec sheet on the GL-4.
You learn something everyday.
-----------------------------------------------------------
PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is specially formulated to meet the unique requirements of API GL-4 service in manual transmissions and transaxles of passenger cars, light trucks and SUV’s. PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is blended from select base stocks and additives that yield a lubricant of exacting quality. This product is compounded utilizing specialized extreme pressure chemistry that provides protection of gears and bearings without being corrosive to bronze components. It contains foam suppressants to prevent wear, which can be caused by lubricant foaming and aeration. Effective rust and corrosion inhibitors protect metal surfaces from the effects of water contamination from condensation and the operating environment. PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT resists the formation of varnish deposits on synchronizer components, thus assuring long, trouble-free operation.
PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 gives the full protection of an SAE 90 under hard driving conditions while providing the flow characteristics of SAE 80W that are necessary during cold weather start-ups. This offers maximum lubrication and gear protection over a wide temperature range.
APPLICATION
PENNZOIL® GEARPLUS® SAE 80W-90 GL-4 GEAR LUBRICANT is designed for manual transmissions and transaxles of both American and import vehicles. It is formulated to be compatible with “yellow metals”, such as bronze, found in synchronizers and other transmission componenets.
BENEFITS
• Meets the performance requirements of API GL-4 Service
• Will not cause glazing of synchronizer components
• Excellent thermal stability
• Outstanding extreme pressure and antiwear protection
• Prevents rust and corrosion
• Inhibits foaming and aeration
07-19-2005, 08:14 PM
#2
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Most modern manual transmissions specify GL-4, which in most cases is satisfied by the Dexron II or III that is the usual specified lubricant.
However, vintage Corvette manual transmissions called for GL-5 when new, and I'm not aware that any of the manufacturers have ever said otherwise since the original gear lube specs were published when they were new. GL-5s have sulphur based EP additives (developed primarily for hypoid axle gears) that some say are corrosive to brass, especially at high temperatures, but I've never heard of a T-10 or Muncie that showed synchronizer corrosion when it was torn down after 40 years of GL-5.
Keep in mind that most of the currently marketed service products - like lubricants - are forumulated for recent vintage cars, and most of the people you talk to who work for these companies weren't even born when our Corvettes were built.
The manual transmission and axle lubricant specification in the 1963 Corvette Shop Manual is SAE 80-90 meeting the Mil-L-2105D specification. Ask your guy which of his modern products meets that specification!
Duke
However, vintage Corvette manual transmissions called for GL-5 when new, and I'm not aware that any of the manufacturers have ever said otherwise since the original gear lube specs were published when they were new. GL-5s have sulphur based EP additives (developed primarily for hypoid axle gears) that some say are corrosive to brass, especially at high temperatures, but I've never heard of a T-10 or Muncie that showed synchronizer corrosion when it was torn down after 40 years of GL-5.
Keep in mind that most of the currently marketed service products - like lubricants - are forumulated for recent vintage cars, and most of the people you talk to who work for these companies weren't even born when our Corvettes were built.
The manual transmission and axle lubricant specification in the 1963 Corvette Shop Manual is SAE 80-90 meeting the Mil-L-2105D specification. Ask your guy which of his modern products meets that specification!
Duke
Last edited by SWCDuke; 07-19-2005 at 08:21 PM.
