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The Difference Between GL-4 and GL-5 Gear Oil

Written by Charleen

The Difference Between GL-4 and GL-5 Gear Oil

The main difference between GL-4 and GL-5 gear oils is in the level of extreme-pressure (EP) additives.

It’s really very simple. They are not interchangeable and GL5 didn’t replace GL4.

by Eddie Yorkman,|July 5, 2022

If you’ve ever purchased gear oil, or spent any time looking at gear-oil specifications, you have undoubtedly come across the API GL-4 and GL-5 specifications. You may have wondered, what is the difference between GL-4 and GL-5 gear oil? Where can I buy GL-4 and GL-5 gear oil?

Severity – Hypoid gears vs Helical

The American Petroleum Institute (API) classifies gears using GL ratings, ranging from GL-1 to GL-5. Higher GL rating numbers represent more severe applications; GL-1 is the least severe and can usually be satisfied with a motor oil, while GL-5 is the most severe GL rating.

EP additives

The main difference between GL-4 and GL-5 gear oils is in the level of extreme-pressure (EP) additives. EP additives effectively protect gears by providing a sacrificial layer on gear surfaces; these additives are essential for protecting gears operating under heavy loads and extreme temperatures. A typical GL-5 gear oil provides about twice as much EP additive in its formulation compared to a GL-4 gear oil.

Where are GL-4 and GL-5 gear oils used?

GL-4 gear oils are typically recommended for spur and helical gears found in manual transmissions and transaxles operating under moderate speeds and loads.

GL-5 gear oils are typically recommended for hypoid gears in automotive axles operating under high-speed, high-load conditions.

What type/weight gear oil should I use?

For top protection and performance, it is best to consult your owner’s manual/Shop manual for the manufacturer’s recommendation. There, you will find both the specified viscosity (75W-90, 75W-140, etc.) and specification (API GL-4, API GL-5, API MT-1, etc.) recommended for your application. Almost all hypoid gear sets require GL-5 due to the need for significant extreme-pressure protection.

Note the 2nd number is the KEY weight under operating temperatures and conditions. 990, 110, 140, 250, etc..  For example our 75W-80 covers and overlaps the recommendations where 80W-90, 85W-90 are written.

What’s the best gear oil for my vehicle?

AMSOIL SEVERE GEAR® Synthetic Gear Lube excels in protecting gears and bearings from the rigors of severe-service operation. By design, it resists breakdown from high heat, preventing acids and maintaining a barrier to prevent metal-to-metal contact while conditioning seals. Its wax-free construction also improves cold-flow properties, improving fuel economy and cold-weather performance.

• Superior film strength
• Controls thermal runaway
• Protects against rust and corrosion
• Helps reduce operating temperatures
• Maximum efficiency
• Long oil, seal and equipment life
• Flexible easy-pack for clean, fast installation

SEVERE GEAR is recommended in differentials, manual transmissions and other gear applications requiring an API GL-5 gear oil. It can also be used in axles where an API GL-4 lubricant is recommended.

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How Often Should I Change Differential Fluid?

Written by Charleen

How Often Should I Change Differential Fluid?

Fluid change intervals depend on your vehicle, driving conditions and gear oil quality.

_by David Paiuilldorf | july 26, 2023

A differential is a set of gears that allows a vehicle’s driven wheels to revolve at different speeds when going around corners or over rough terrain. Those gears require lubrication, which is commonly called differential fluid, gear oil, or gear lube.

How often you should change differential fluid depends on your vehicle, driving conditions and fluid quality. If you drive primarily on the highway in temperate conditions and rarely tow or haul, you won’t need to change the differential fluid very often.

However, severe operating conditions break down differential fluid more quickly and place greater stress on the gears and bearings, inviting wear that reduces their lifespan.

Greater load capacity, less lubrication.

Truck manufacturer’s ongoing arms race for the highest towing capacity has resulted in trucks that place more stress on differentials than their predecessors. Meanwhile, differential fluid capacities have largely decreased or remained the same.

For example, compare a 1996 Ford F-250* Crew Cab to the 2021 version. Back in 1996, maximum towing capacity was 10,500 lbs. using a rear differential that held 3.75 quarts of gear oil. The 2021 model offers up to 15,200-lb. towing capacity using a rear differential that holds between 3.3 and 3.5 quarts of fluid.

This means less lubrication is responsible for protecting gears among higher heat and stress. In this environment, inferior lubricants can shear and permanently lose viscosity. Once sheared, the fluid film weakens, ruptures and allows metal-to-metal contact, eventually causing gear and bearing failure. That’s not good!

Increased temperatures in differential

As temperatures rise, lubricants lose viscosity and the extreme pressure between gears can shear the lubricant film, causing increased metal-to-metal contact, friction and heat. Friction and heat create a vicious cycle known as thermal runaway that spirals upward, leading to increased wear and potential gear failure.

Oh and let me tell you a quick story about AMSOIL diff fluid. Under thermal runaway the heat causes the gears or metal to expand just enough to act like a brake. We’ve had RVs comment on reaching 5 to 7 more miles per hour on mountain passes due to the reduction of heat using the AMSOIL Severe Gear. See what I’m saying?

Severe Service Differential Fluid Solution

If you drive via Severe Service towing conditions or haul heavy loads frequently, especially in warmer temperatures, most manufacturers recommend changing the differential fluid more often, sometimes as often as every 30,000 miles. This applies to most work trucks and anyone who pulls a camper, boat or trailer regularly

The best way to determine the recommended mileage interval for differential fluid changes is to check your owner’s manual. Use a high-quality synthetic gear oil to reduce gear wear and maximize your vehicle’s ability to tow and haul.

Amsoil’s Severe Gear Squeeze or Easy-Pack

Amsoil Squeeze Packs cut the differential oil change process in half!

AMSOIL SEVERE GEAR Synthetic Gear Lube is specifically designed for severe service. It maintains viscosity better than other gear lubes under rigorous use and contains advanced anti-wear additives for additional protection.

SEVERE GEAR often costs less than OEM-branded gear oil, and the AMSOIL Easy-Pack or I call Squeeze Pack eliminates the frustrations of changing gear oil. Its flexible design lets you easily reach inconvenient fill holes and squeeze all the gear lube out of the package. Less mess, less waste, less frustration.

And hey, by the way most auto parts stores don’t even carry a known name brand GL5 gear lube these days. Tell your auto parts store to PLEASE carry AMSOIL as it’s about the only real performance player out there and the only one that really works..

 

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No Fear and Loathing at the Mint 400

Written by Charleen

No Fear and Loathing at the Mint 400

Lindsay Premo|

“In some circles, the Mint 400 is a far, far better thing than the Super Bowl, the Kentucky Derby and the Lower Oakland Roller Derby Finals all rolled into one. This race attracts a special breed…”  – Hunter S. Thompson

In 1971, author Hunter S. Thompson wrote his famous article “Fear and Loathing in Las Vegas” while covering the Mint 400 for Sports Illustrated. Thompson’s article was later adapted into a novel and then into a film starring Johnny Depp and Benicio Del Toro, signifying the Mint 400’s relevance to American pop culture.

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The Mint 400 started in 1967 near Las Vegas as a public relations event to promote the Mint Hotel’s annual deer hunt. Race organizers sent two matching dune buggies 600 miles through the desert from the Mint Hotel to the Sahara Hotel in Lake Tahoe, Calif. The event because famous overnight, with national television coverage drawing the attention of race fans across the country.

Some of the “special breeds” who have competed in this event include Al and Bobby Unser; Rick Mears; Mickey Thompson; actors Steve McQueen and Patrick Dempsey; and comedian Jay Leno.

AMSOIL racers to take to the desert

Coming off an impressive seventh-place finish at the King of the Hammers UTV race last month, two-time Mint 400 champion Bryce Menzies is looking to do it again in this year’s Trick Truck class. His fellow #TeamAMSOIL racer Brad Lovell is also looking to keep the momentum going following a second-place finish at last month’s King of the Hammers EMC. Lovell, who took second in the Vintage Open Class at last year’s Mint 400, will be competing in his first ever 6100 race.

Prior to racing on Friday, Lovell’s pit crew will participate in the Method Race Wheels Pit Crew Challenge along Fremont Street on Thursday evening.

Stop by the AMSOIL booth

AMSOIL will be located on Fremont Street throughout all the pre-race events. Be sure to stop by and pick up your exclusive Runs on Freedom™ bandana. Fill out our survey on Friday, March 8 for a chance to win the fender from Lovell’s new 6100 truck following the race.

On Thursday and Friday, Menzies’ UTV from King of the Hammers will be on display. Lovell’s Bronco will be displayed Thursday and his new 6100 on Friday. Both Menzies and Lovell will be in the booth Friday at 2 p.m. local time signing autographs for fans.

Buy two SEVERE GEAR® easy-packs, get one free

We’re also offering a special promotion as part of our Mint 400 partnership. Buy two AMSOIL SEVERE GEAR Synthetic Gear Lube easy-packs and get one free. It’s the same gear lube Menzies and Lovell trust in their race vehicles.

Find more information on the promotion here.

As always, tune into our social media channels for updates throughout the race. The week kicks off Wednesday, March 6 in Las Vegas. Check out the complete schedule of Mint 400 events here.

Facebook

Instagram

Twitter

We’ll see you at the races!

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2019 AMSOIL Year in Review: Product & Company News

Written by Charleen

2019 Year in Review: AMSOIL Company News

Jamie Gibson|

Editor Note: – This is being posted late but that’s alright as AMSOIL’s year starts now in August when things really get started for us – Summer maintenance and in northern climates not far is the season to wrap things up for winter.

As we near the end of yet another decade, we here at AMSOIL are reflecting upon a year of product development, corporate partnerships and the promise of continued success as we head into 2020.

Take a walk down memory lane with us in this installment of the 2019 AMSOIL Year in Review: Product & Company News.

January

We kicked off the year with further immersion into the wind-turbine market.

AMSOIL products are now installed in nearly 50 percent of all wind turbines in the U.S. along with more in Europe, China, India, Brazil and others. This initiative further validates the protection and performance of AMSOIL lubricants in the most demanding operating conditions.

Several manufacturers now use AMSOIL as their OEM factory fill.

AMSOIL Diesel Injector Clean + Cetane Boost launched, offering diesel owners a convenient option to protect their fuel systems.

This new product combines superior detergency and improved lubricity while increasing horsepower and cetane up to 8 points. Oh, and it won a prestigious award before the end of the year, too. More on that below.

Diesel Injector Clean + Cetane Boost

February Updates

AMSOIL Signature Series 5W-30 Max-Duty Synthetic Diesel Oil gets an update.

This top-tier oil represents one of the most versatile products in the AMSOIL lineup by meeting the latest diesel and gasoline specifications including API CK-4 and API SN PLUS.

It features the combined wear protection benefits of a 15W-40 with the fuel economy benefits of a 5W-30.

March Addition

AMSOIL MP Metal Protector becomes even more convenient with the addition of 4-ounce aerosol packaging.

This product is truly a jack-of-all-trades for almost any application. Find ideas here and keep this one in mind for stocking suffers next year.

MP Metal Protector

April in New Packaging

The award-winning AMSOIL easy-pack expands into the powersports market with the addition of AMSOIL ATV/UTV Transmission & Differential Fluid and AMSOIL Synthetic 75W-90 Marine Gear Lube.

May- more EZ Packs!

Five more easy-pack offerings make their way into the AMSOIL lineup, reducing mess, waste and frustration for even more applications.

AMSOIL Signature Series Multi-Vehicle Synthetic ATF
AMSOIL Signature Series Fuel-Efficient Synthetic ATF
AMSOIL Manual Transmission & Transaxle Gear Lube 75W-90
AMSOIL SEVERE GEAR® Synthetic 75W-110 Gear Lube
AMSOIL SEVERE GEAR® Synthetic 80W-90 Gear Lube

June – 10W-30 Breakthrough

AMSOIL introduces new Signature Series Max-Duty 10W-30 Synthetic Diesel Oil.

In store here in Sioux Falls it’s become a hit!! Available at Stan Houston’s too.

It delivers excellent viscosity control, extended drain intervals and 6X better wear protection than required by the Detroit Diesel DD13 Scuffing Test for Specification DFS93K222.

That’s very techy, we know, but it means we exceed the highest standards.

Amsoil Signature Series Max-Duty Synthetic Diesel Oil 10W-30

July

AMSOIL revamps its powersports Product Guides, making up one of just two such guides available in the industry.

Due to the high level of research and maintenance such guides require, most lubricant and filter companies take a hard pass on offering this kind of tool.

The AMSOIL Product Guides deliver recommendations for more than 225 different equipment brands and nearly 180,000 components across all spectrums of the powersports industry.

Whatever your application, if you’re in need of an AMSOIL product recommendation, find it here.

October

The 2019 AMSOIL Direct Jobber Convention takes place in Scottsdale, Ariz.

AMSOIL President & CEO Alan Amatuzio and other corporate staff mingled with AMSOIL Direct Jobbers for training, networking and an Arizona luau topped off with a fireworks display. Good times were had by all with attendees gaining invaluable knowledge and motivation to grow their AMSOIL businesses.

Find out if becoming an AMSOIL Dealer is right for you.

AMSOIL 5W-30 Synthetic Small Engine Oil hit the market to round out the small-engine-oil family.

Recommended primarily for snowblowers and generators, this was a welcome addition for those who need their equipment to perform in extreme temperatures and conditions.

Amsoil 5W-30 Synthetic Small Engine Oil

AMSOIL Upper Cylinder Lubricant came right out of the gate ahead of the competition.

This premium gasoline fuel additive delivers 18 percent more lubricity than Lucas* and 20 percent more than Sea Foam* for better retention of horsepower and fuel economy¹.

Upper Cylinder Lubricant

¹Based on independent testing of AMSOIL Upper Cylinder Lubricant, Lucas Upper Cylinder Lubricant and Sea Foam Motor Treatment obtained on 02/13/2019 using the ASTM D6079 modified for use with gasoline.

(Do fuel additives work? Find out here.)

December

Closing out the year was a win for AMSOIL Diesel Injector Clean + Cetane Boost at the 2019 Performance Racing Industry (PRI) Show in Indianapolis, Ind.

Selected as one of the winning products from more than 500 entries, Indian journalist Aatish Mishra of Motor Sport India Magazine chose this product with the following sentiments in mind:

“Diesel passenger cars are immensely popular in India, and a lot of enthusiasts like to tune up their diesel-engine cars,” said Mishra of his selection. “A product like what AMSOIL has showcased would go down well with this group of people. It would provide them better quality fuel and allow their cars to run better.”

This covers the notable company and product highlights from the final year of the decade, and what a great one it was.

Stay tuned for a recap of our exciting racing and event highlights from our resident expert, Race & Events Coordinator Lindsay Premo.

See you in 2020!

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More AMSOIL Products Available in the Award-Winning Easy-Pack

Written by Charleen

The New EZ Pack is making waves! No more oil change Hassle

Jamie Gibson|

Sometimes an idea so great comes along it makes some wonder, “Why didn’t anyone think of this sooner?”

Case in point: AMSOIL easy-packs. Their innovative, flexible design has revolutionized the challenging task of changing fluids, reducing mess, waste and hassle.

Less Mess. Less Waste. Less Hassle.

After extensive research and testing to produce a concept worthy of the AMSOIL name, the AMSOIL SEVERE GEAR® Synthetic Gear Lube easy-pack launched in August 2018 to resounding success. It has earned rave reviews, a SEMA Global Media Award, a Flexible Packaging Achievement Award and the expectation that other companies will soon attempt to follow the AMSOIL lead once again.

Here’s what one customer says about the SEVERE GEAR easy-pack.

“175,000 trouble-free, heavy-haul miles. The new gear oil pouch makes it so easy to change diff fluid. Make the switch to AMSOIL today. Proven protection in the worst conditions.”

Nate the Hotshot
Laurel, Miss.

Since the launch of the AMSOIL SEVERE GEAR Synthetic Gear Lube easy pack, AMSOIL has expanded its easy pack offerings to include even more products. Check those out below and prepare for a new way of changing fluids with less stress and mess than what you’re used to enduring.

SEVERE GEAR Synthetic Gear Lube

Available in 75W-90, 80W-90, 75W-110 and 75W-140 viscosities, SEVERE GEAR is engineered for high-demand applications found in today’s autos/pick-up trucks, SUVs, heavy equipment and other hard-working vehicles. It delivers extreme-temperature performance no matter where the roads you travel happen to be.

Synthetic ATV/UTV Transmission and Differential Fluid

AMSOIL Synthetic ATV/UTV Transmission and Differential Fluid delivers severe-service protection against wear while riding aggressively or tackling tough terrain around your property. It protects heavily loaded, high-torque gears to promote long equipment life, even in extreme operating temperatures.

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Bonus: AMSOIL synthetic lubricants are Warranty Secure, keeping your factory warranty intact. Click here to learn more about your freedom to choose the lubricants you think best – and to score your free AMSOIL Runs on Freedom decal.

Synthetic Marine Gear Lube

AMSOIL Synthetic Marine Gear Lube is an exclusive AMSOIL formulation of synthetic base oils and high-performance additives that address specific concerns of marine applications. It is fortified with extreme-pressure (EP) additives for superior protection of fast-accelerating, high-torque/horsepower engines. It delivers advanced outboard protection against power loss and gear wear, even with up to 15 percent water contamination.*

*Based upon AMSOIL testing of AMSOIL Synthetic Marine Gear Lube 75W-90 in ASTM 3233 and ASTM D892.

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Signature Series Synthetic Automatic Transmission Fluid

Available in both Fuel-Efficient and Multi-Vehicle formulations, AMSOIL Signature Series ATF provides excellent wear protection and performance in today’s demanding transmission applications. Benefits include protection against thermal breakdown, cold-temperature fluidity, friction durability and maximum fuel economy.

Manual Transmission & Transaxle Gear Lube

AMSOIL Manual Transmission & Transaxle Gear Lube is formulated to meet the demands of towing, heavy hauling and performance driving typically found in manual transmissions. It delivers quick shifts and excellent wear protection in hot rods and muscle cars to promote smooth, fast engagement of synchronizers and gears. Its shear-stable formulation maintains viscosity and protects brass synchronizers while supporting equipment longevity.

Shop AMSOIL Easy Packs

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