9 Best 75w140 Synthetic Gear Oil Reviews 2022
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75w140 synthetic gear oil is a type of lubricant that has been designed for high-speed applications. It provides excellent protection against wear and corrosion, but it also offers superior shear stability.
This means that the lubricant will not break down as quickly or have its viscosity reduced when exposed to extreme temperatures. 75w140 synthetic gear oil is commonly used in power steering units, transmissions, differentials, hydraulic systems and other heavy duty equipment.

In A Hurry? Here Are Our Top 5 Picks!
Image | Product | Key Features | Price |
---|---|---|---|
1. Valvoline SynPower 75W-140 Gear Oil | ● Item Weight: 1.9 pounds. ● Auto & Truck Maintenance. ● Contains special additives. ● Provides outstanding thermal stability. |
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2. Lucas 75/140 Synthetic Gear | ● Item Weight: 7.6 pounds. ● Long-lasting lubricant. ● Best for high-performance applications. ● Designed to stand up to high temperatures. |
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3. Royal Purple Max 75W140 Gear Oil | ● Item Weight: 2 pounds. ● Reduces operating temperature. ● Superior corrosion protection. ● Environmentally responsible. |
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4. ACDelco 75W-90 Axle Gear Oil | ● Item Weight: 1.75 pounds. ● Pairs of long fluid life. ● Improved formula. ● Provide a pleasing grape scent. |
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5. Mobil 1 175W-140 Synthetic Gear Lube | ● Item Weight: 1.7 pounds. ● Excellent wear protection. ● Prevents corrosions. ● Suitable for large vehicles. |
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Best 75w140 Synthetic Gear Oil Reviews
1. Valvoline 75W-140 Synthetic Gear Oil
Valvoline SynPower Full Synthetic Gear Oil is the best 75W-140 Synthetic Gear Oil in our list that is a high performer. If you are the owner of a ford or other similar vehicle, you can consider this gear oil. It is formulated to offer and maintain brilliant low-temperature fluid protection.
Besides, the gear oil can offer the highest thermal stability while handling a range of temperatures without its viscosity. The feature will allow you to maintain a much cleaner engine and transmission.
In this way, synthetic gear oil will improve your vehicle’s life span. However, the gear oil doesn’t perform better in hot and cold conditions, but it can hold its own.
On the other hand, it comes with special additives designed so that the engine can prevent corrosion, rusting, and friction. If you are concerned about protecting your transmission, it is one of the best options you should go for.
2. Lucas 75w140 Synthetic Gear Oil
If you are looking for gear oil suitable for heavy-duty trucks for getting high performance, you can try this Lucas Synthetic Gear Oil. It is specially designed as a long-lasting and nonfoaming lubricant suitable for both trucks and large vehicles where ordinary gear oil is unable to work.
On the other hand, it’s a super slick type of synthetic gear oil that will allow for the least friction. So it will not only reduce transmission wear and tear but ultimately offer longer transmission life.
The highlight feature of this 75W-140 synthetic gear oil is it will work on lower operating temperatures and perform in hot conditions. Without losing viscosity, this synthetic gear oil can easily stand up to high temperatures.
Besides, it comes with a special additive package to resist squeezing out under great pressure situations. Finally, this high performer, synthetic oil, is available at an affordable price.
3. Royal Purple Max 75W140 Gear Oil
This Royal Purple Max Gear Oil is designed to maximize the horsepower that possibly you are looking for. In this case, synthetic gear oil will be the best option for towing. The most interesting feature of this gear oil is it meets warranty requirements.
So it will keep you away from avoiding your warranty by applying it. Most importantly, the manufacturer formulates this synthetic gear oil in such an incredible way that it will impact a minimal on the environment. It also designs to help increase both bearing life and gear in large vehicles.
Similarly, the gear oil will be suitable for operating at high temperatures. It can reduce the operating temperature of transmissions to offer you a longer lifespan. With superior corrosion protection features, the gear oil will reduce the friction coefficient and provide long-lasting service.
4. ACDelco 75W-90 Synthetic Axle Gear Oil
This ACDelco Synthetic Axle Gear Oil is withstood high temperatures encountered while retaining fluidity at cold temperatures. Besides, it’s heavy-duty and extreme-temperature-pressure gear oil in the market that is available at a reasonable price.
So if you are on a tight budget and still considering an improved formula that comes with a grape scent for a more pleasant application experience, you can try this ACDelco Synthetic Axle Gear Oil.
Besides, it greatly meets (API) GL-5 specification that allows you to use it in severe conditions. On the other hand, this fully synthetic formulation gear oil offers oxidation and thermal stability. This product pairs a long fluid life that will impress you.
5. Mobil 1 75W-140 Synthetic Gear Lube
Suppose you are looking for 75W-140 Synthetic Gear oil that will allow you to use it in various vehicles, including passenger vehicles, pickups, SUVs, and other large vehicles. In that case, this Mobil 75W-140 Synthetic Gear Lube will be the right option for you.
Besides, you can use this for limited-slip type differentials. Even you don’t need an LS additive in most cases. The highlight feature of this gear oil comes with a unique set of additives to deliver optimal viscosity-temperature properties.
It means the gear oil will stay thin enough to perform in cool conditions without losing its viscosity in high operating temperatures. If you want to try something that helps prevent friction, rust, and wear, it will still be a suitable option.
Finally, it will help you get the most HP and mileage; however, it is surprisingly available at a low cost.
6. Castrol Syntrax Limited Slip 75W-140 Synthetic Gear Oil
This 75W-140 Synthetic Gear oil from the Castrol brand is best for protecting high loads and prevents damage to the component. Besides, it will boost durability for the highest protection under harsh driving conditions. With exceptional stability at high temperatures, it will help to extend the life of lubricant and axle.
As the manufacture formulates this synthetic gear oil with a high-quality design, it will not only improve thermal stability but unsurpassed shear stability for better wear protection. The best part of this gear oil is it will modify friction for use in both limited and conventional slip axles.
The feature will also reduce noise and vibrations in the axle. So if you are looking for synthetic gear oil that will be especially suitable for BMW rear axles, 4WD axles, and light commercial vehicles and available at low cost, you can choose this one.
7. TriboDyn 75W-140 Synthetic Gear Oil
It is introducing the TriboDyn 75W-140 Synthetic Gear Oil, which is the first oil to get a U.S. Functional Patent in over 30 years. It offers a full line of synthetic engine oils blended with TriboDyn additives. So your vehicle will have the ability to reduce friction and heat while producing more power.
The feature will allow the vehicle to handle the RPM’s of 2 cycle engines and extreme heat. At the same time, it will help to increase fuel efficiency. The best part of synthetic gear oil is it comes to work under extreme conditions.
However, it’s a bit pricy option, but it will be worth of investment while you will find extended engine life and easier starts advantage.
8. Red Line 75W140 Synthetic Gear Oil
Next, we have Red Line Synthetic Gear Oil. This 75w-140 synthetic gear oil is especially suitable for both large and short vehicle that needs gear oil of this viscosity. Being 75w140 in viscosity, this synthetic gear oil will do a great job at high operating temperatures.
The feature makes it suitable for a range of models, including API GL-5, GL-6, and SAE J2360. At the same time, the gear oil is design to reduce friction and corrosion in vehicles. Putting this gear oil onto your vehicle, you will not only have greatly extended the lifespan of the transmission, but it will boost HP.
Plus, it comes with additional friction modifiers that make the oil suitable for clutch-type limited-slip differentials. It means you don’t need any extra modifiers. Finally, the best synthetic gear oil is available at an affordable cost.
9. AMSOIL 75w140 Synthetic Gear Oil
The last option in our list is AMSOIL, fully synthetic gear oil that comes to perform in extreme driving conditions.
Besides, it has the ability to serve the intended engine demands as it comes in the premium formulation. With incredible lubricating properties, the gear oil can initiate lowered metal friction to waste power.
On the other hand, a heavy-duty class 8-line haul makes it worth or investment. Most importantly, synthetic gear oil can endure the huge stress of off-road adventures.
So whether you use it on SUV, standard car, or light truck, you will get the highest serviceability. To maintain a balanced interior environment, the gear oil includes the integration of cleaning additives. So you have to face any corrosion problem.
Why use Synthetic Gear Oil?
Most of the people got confused about why they would use synthetic gear oil rather than mineral gear oil? Let’s clear it! The main reason is synthetic oil performs much better than mineral oil under extreme conditions, especially under extreme heat or cold.
At the same time, most of the large vehicles are operating at extreme temperatures, even in extreme heat. As a result, these need synthetic gear oil to offer high performance.
What Does 75W-140 Mean?
To get the most out of gear oil as a vehicle owner, you should know what the make indicates that come with gear oil. So what does 75W-140 mean that comes with synthetic gear oil? The depicted value indicates fluidity or viscosity. W stands for winter suitability. If you find a Numeric value right before the ‘W,’ you have to understand it determines the cold temp flowability.
Actually, transmission gearbox oil is available in a liquid state up to -40°C. The latter ‘140’ indicates the efficient kinematic viscosity of the featured oil at 100°C.
How to pick the Right 75W140 Synthetic Gear Oil?
There are a vast number of options that you have to consider while buying synthetic gear oil, especially 75W140 gear oils. So you can’t choose anything based on label judgment. In this case, the following essential points will help you to ensure the best buy.
System Specs
The first and foremost will go with the recommendation. It is must necessary to look into the vehicle manual to find the right option. Besides, you should not change the brands for any specified preferences.
Stable Molecules
Most of the fuel comes with a 100% synthetic formula. To ensure the highest response on demand, uniformity also prevails. But you should recheck the acceptance concerning its ability to stand the rigors.
Fuel Grade
As most of the vehicle owners aren’t experts, so classified gear oil based on grading may not help to get the exact result. For example, W has lots of variation. Apart from SAE, it will be better to settle with GL-5 to get a better response.
Chemical Agents
Gear oil is always better than mineral fluid. But the question is what makes the difference? The answer is chemical compounds. So you can get knowledge about additives to support the operational severity.
Slippery Action
If you have heavy-duty gearbox applications, you should not use just regular oils. In this case, synthetic gear oil comes with superb lubrication capability that makes it higher than mineral ones. So before buying, you should confirm its lubricating properties.
FAQs
What Is 75W140 Gear Oil?
75w140 is a gear oil, or u0022gear lubricant that is typically used in cars for the differential gears, limited slip differentials (u0022LSDu0022), and transfer cases. In trucks, it is also commonly used for hypoid rear axles.
Is All 75 140 Gear Oil Synthetic?
The answer is ‘No’. There are two types of oils that meet API (American Petroleum Institute) SN performance level. One is fully synthetic and the other is a ‘special’ blend.
Final words
We have covered this best 75W-140 Synthetic Gear Oil article with top quality, long-lasting, and heavy-duty 75W-140 Synthetic Gear Oil that is available in the market. Even our buying guide can help you find the right one from the broad market.
Still, if you have any confusion and want to know our editor’s choice, it will be Valvoline SynPower 75W-140 Synthetic Gear Oil. It is available at a low cost that is ready to offer great thermal stability with extreme performance.