1-800-956-5695 Tracking #414157
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AMSOIL Synthetic Gear Lube Outperforms Valvoline Gear Lube
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High quality gear oils must lubricate, cool and protect geared systems. They must
also carry damaging wear debris away from contact zones and muffle the sound of
gear operation. Commonly used in differential gears and standard transmission
applications in commercial and passenger vehicles, as well as a variety of industrial
machinery, gear oils must offer extreme temperature and pressure protection in
order to prevent wear, pitting, spalling, scoring, scuffing and other types of damage
that result in equipment failure and downtime. Protection against oxidation, thermal
degradation, rust, copper corrosion and foaming is also important.
AMSOIL submitted its 75W-90 Synthetic Gear Lube (AGR) and Valvoline
75W-90 Gear Lube to an independent laboratory for quality comparison tests. The
gear lubes were tested according to
ASTM testing procedures in several critical performance areas, including oxidation resistance, viscosity retention and cold temperature fluidity.
Oxidation resistance was measured using the L-60-1 Thermal Oxidation Stability Test, viscosity retention was measured using the KRL Shear
Stability Test and cold temperature fluidity was measured using the Brookfield Viscosity Test. Additional load carrying, wear, extreme pressure and
scoring protection tests were performed exclusively on AMSOIL 75W-90 Synthetic Gear Lube using the L-37 High Torque Axle Test and the L-42
High Speed Axle Test.
L-60-1 Thermal Oxidation Stability Test
L-60-1 Thermal Oxidation Stability Test Specifications
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API GL-5
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API MT-1/SAE J-230
MIL-PRF-2105E/MAC GO-J
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Mac GO-J+
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Test Conditions
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50 hours @ 163 deg C
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50 hours @ 163°C
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100 hours @ 163°C
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Viscosity Rise, %
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100 Max.
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100 Max.
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100 Max.
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Pentane Insolubles, %
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3 Max.
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3 Max.
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3 Max.
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Toluene Insolubles, %
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2 Max.
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2 Max.
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2 Max.
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Carbon Varnish, rating
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Not required
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7.5 Min.
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7.5 Min.
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Sludge, rating
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Not required
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9.4 Min.
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9.4 Min.
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L-60-1 Thermal Oxidation Stability Test Results
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AMSOIL Synthetic
75W-90
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Valvoline
75W-90
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Valvoline
75W-90
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Test Conditions
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100 hours @ 163°C
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50 hours @ 163°C
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100 hours @ 163°C
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Viscosity Rise, %
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25.17
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17.50
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38.50
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Pentane Insolubles, %
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0.20
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0.87
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1.17
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Toluene Insolubles, %
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0.13
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1.11
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0.99
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Carbon Varnish, rating
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8.0
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7.2
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5.9
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Sludge, rating
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9.5
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9.4
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9.4
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Test Results
Because AMSOIL 75W-90 Synthetic Gear Lube is a premium lubricant designed for extended drain service, the test was allowed to continue for 100
straight hours, double the standard test length. The Valvoline 75W-90 was run at both the standard 50-hour test length and the double 100-hour test length.
Test results indicate AMSOIL 75W-90 Synthetic Gear Lube outperformed Valvoline at both test lengths.
Even at double the standard test length, AMSOIL 75W-90 scored almost four times better than industry test specifications in the area of viscosity increase,
while also greatly exceeding specifications in all areas of the test.
The photographs below show the superior deposit-control characteristics of AMSOIL 75W-90 Synthetic Gear Lube.
L-60-1 Thermal Oxidation Stability Test Results
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Even after enduring a double-length, 100-hour L-60-1 Thermal Oxidation Stability Test, AMSOIL 75W-90 Synthetic Gear Lube produced significantly
fewer deposits than the Valvoline 75W-90 run at a standard, 50-hour test.
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KRL Shear Stability Test
Test Conditions
It is essential that high-quality gear lubes resist shear to ensure adequate oil film thickness and protection against friction and wear. The KRL Shear Stability
Test is used to determine the mechanical shear stability of lubricants containing polymer. Mandatory under the SAE J-306 gear oil standard, the KRL Shear
Stability Test makes use of a taper roller bearing in order to shear the test fluid and determine the permanent drop in viscosity caused by the mechanical
stress under practical conditions. Under the specifications of SAE J- 306, the measured viscosity at 100°C (212°F) of an SAE 90 gear oil must exceed
13.5 cSt after 20 hours of testing.
Test Results
AMSOIL 75W-90 Synthetic Gear Lube easily exceeded SAE J-306 specifications following the 20-hour test length and was allowed to continue for a total
of 192 straight hours, almost 10 times longer than the standard test length. Even after this extended test, AMSOIL 75W-90 lost only 0.40 percent of its
original viscosity, making it 99.6 percent shear stable.
Valvoline 75W-90 Gear Lube, on the other hand, failed the test during the initial 20-hour testing period, losing 14 percent of its original viscosity.
Brookfield Viscosity Test
Test Conditions
The Brookfield Viscosity Test (ASTM 0-2983) is used to determine the internal fluid-friction of a lubricant during cold
temperature operation. The lubricant sample is chilled in a -40°C (-40° F) air bath for 16 hours, and a Brookfield
viscometer determines the torque required to shear the lubricant. The lower the cold temperature viscosity (measured
in centipoise), the better the cold temperature protection. ASTM specifications dictate that 75W-90 gear oils measure
less than 150,000 cP at test completion.
Test Results
AMSOIL 75W-90 Synthetic Gear Lube easily passed the Brookfield Viscosity Test, measuring 88,000 cP at test
completion, 42 percent less than test limits. The superior cold temperature properties of AMSOIL 75W-90 Synthetic
Gear Lube ensure quicker oil flow, enhanced component protection and improved fuel efficiency.
Many conventional lubricants fail to pass the Brookfield Viscosity Test due to the paraffinic (wax) content in their base
oils. Valvoline Gear Lube passed the test at 130,000 cP, only 13 percent lower than test limits.
The gears protected by AMSOIL 75W-90
Synthetic gear Oil showed little or no
rippling, ridging, pitting or deposits following
the L-37 High Torque Axle Test.
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1-37 High Torque Axle Test
The gears protected by AMSOIL 75W-90 Synthetic gear Oil showed little or no
rippling, ridging, pitting or deposits following the L-37 High Torque Axle Test.
Test Conditions
The L-37 High Torque Axle Test is used to evaluate a gear lubricant's load-carrying,
wear and extreme pressure characteristics in hypoid gears operating under both
high-speed/low-torque and low-speed/high-torque conditions. A Dana Model 60
hypoid gear axle is used with either coated or uncoated drive gear and pinion to drive
two dynamometers from an eight-cylinder, 5.7-liter gasoline engine. With the axle filled
with the test lubricant, the high-speed/low-torque test is performed for 100 minutes, with
the gears visually assessed afterwards. Next, the low-speed/high-torque test is run for
24 hours, followed by a thorough inspection of the gears. Performance relative to API
GL-5 and MIL-PRF-2105E specifications is assessed based on tooth surface rippling,
ridging, pitting and wear, deposits and discoloration.
Test Results
Testing on AMSOIL 75W-90 Synthetic Gear Oil was conducted using uncoated gear and pinion. The AMSOIL lubricant passed on all counts and showed little
to no rippling, ridging, pitting or deposits, indicating that AMSOIL 75W-90 provides superior protection and performance under extreme pressure conditions.
L-42 High Speed Axle Test
Test Conditions
The L-42 High Speed Axle Test evaluates the antiscoring characteristics of a gear lubricant operating under high-speed and shock-loading conditions. A Spicer
Model 44-1 hypoid gear axle is driven by a 5.7 liter, V8 gasoline engine with a four-speed truck transmission and two high-inertia dynamometers and hard
accelerated to 100 mph. The axle is periodically shock-loaded through a dynamometer to simulate high shock-loading conditions. The axle is accelerated
through the gears to 1,050 r/min and decelerated to 530 r/min. This cycle is repeated five times, followed by 10 shock loadings. In order to meet API GL-5 and
MIL-PRF-2105E gear oil specifications, scoring must be equal to or better than gears tested with a reference oil.
Test Results
AMSOIL 75W-90 Synthetic Gear Oil easily passed the L-42 High Speed Axle Test, receiving
a significantly better rating than the reference oil and leaving little to no scoring on the ring and
pinion.
The gears protected by AMSOIL 75W-90 Synthetic
gear Oil showed little to no scoring following the L-42
High Speed Axle Test.
L-42 High Speed Axle Test
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AMSOIL 75W-90
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Reference Oil
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Ring
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13
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19
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Pinion
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18
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27
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Test Conditions
The L-60-1 Thermal Oxidation Stability Test measures a lubricant's rate of deterioration under severe oxidation conditions. A measured sample of
test lubricant is placed in a special gear case with two spur gears and a copper catalyst strip. The gears are driven at 1,725 rpm at 163°C for a
50-hour duration, while air is bubbled through the sample.
Viscosity increase, deposits not soluble in pentane or toluene, carbon varnish and sludge deposits are measured upon test completion. Test
specifications are listed below.
KRL Test Results
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AMSOIL 75W-90
(After 192 hrs. KRL)
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Valvoline 75W-90
(After 20 hrs. KRL)
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Beginning Viscosity @ 100°C (cSt)
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15.09
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14.46
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Ending Viscosity @ 100°C (cSt)
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15.03 (pass)
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12.42 (fail)
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% Viscosity Loss, 100°C
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0.40%
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14.10%
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