the manual for my Landpride FDR 1660 finisher mower gearbox states using 80-90W EP gear lube and the manual for my Landpride bx5450 snow thrower gearbox states SAE 80W90. Are these two gear lubes close enough to be used in both?
Gearbox Lube 80-90W EP vs SAE 80W90
- Thread starter bhartel63
- Start date
The key to your question are the letters EP which stands for Extreme Pressure.
Gears are not all the same and some designs put a great deal more pressure on the two mating surfaces hence the need for the extreme pressure additive.
Do your equipment a favour and use exactly what is specified.
Daave
Gears are not all the same and some designs put a great deal more pressure on the two mating surfaces hence the need for the extreme pressure additive.
Do your equipment a favour and use exactly what is specified.
Daave
TheOldHokie
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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
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GL5 is an EP (extreme pressure suitable) gear oil, GL4 is the non-EP counterpart.
In general, you could use GL5 as an upgrade from GL4 but NOT GL4 in a GL5 application. HOWEVER if the non-EP application has gearbox components sensitive to sulphur and/or phosphorous which are typical part of the additive package to provide for the extreme shock loading spec of EP/GL5 type lubricants then do not use GL5 if GL4 was the original spec.
Rodger
In general, you could use GL5 as an upgrade from GL4 but NOT GL4 in a GL5 application. HOWEVER if the non-EP application has gearbox components sensitive to sulphur and/or phosphorous which are typical part of the additive package to provide for the extreme shock loading spec of EP/GL5 type lubricants then do not use GL5 if GL4 was the original spec.
Rodger
TheOldHokie
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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Factually incorrect and outdated information.
The GL4 service category is an EP gear oil suitable for use in mild to lightly loaded low to medium speed axles subject to mild to moderate shock loads. Not suitable for use in hypoid axles.
GL5 is an EP gear oil suitable for use in high speed heavily load axles subject to severe shock loads and/or equipped with hypoid gear sets.
The GL4 specification is obsolete and has been for decades. The test methods and axles used to evaluate perfornance are long gone. API currently allows GL4 labeling for gear oils containing an EP treat rate of 50% of a GL5 oil.
Modern GL5 formulations use buffered EP compounds which only activate at very high localized (gear tooth contact patch) surface temperatures and typically score very low (1A or 1B) on ASTM D130 yellow metal corrosion tests. They pose no danger to any yellow metal in a low speed implement gear box.
Dan
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