Duramax Allison Transmission Fluid Type-Complete Guide

By: Saiful Islam | May 7, 2022

The Duramax engines are one of the leading engines across the world. The Duramax engine always comes with the Allison transmission, making it more functional and high-performing.

However, the most important question is, what is the best Fluid Type of Duramax Allison Transmission?

Well, with the advancement in technology, there is a wide variety of quality transmission fluids for Duramax Allison Transmission System that are more stringent standards and improve anti-oxidation, anti-wear, and anti-shudder qualities. 

This article will give you complete information regarding the best Duramax and Allison combination transmission fluid type, which will help you understand and choose the best transmission fluid type for your car.

Overview: Duramax Allison Transmission Fluid Type 

The Duramax V8 6.6L is one of the leading engines from Dmax Company, the partner Company of General Motors and Isuzu.

The best transmission fluids of Dexron or the Mercon are the Automatic Transmission Fluid for the Duramax engines.

It is perfect for Automatic Transmission Fluid for Allison Transmission. These are Allison-approved transmission fluids. 

Also, the Duramax engine-specific synthetic ATF, such as the Castrol Transynd fluid formulated for today’s world’s latest and most advanced transmission system. 

It is ideal for the electrically operated General Motors cars, Chrysler vehicles, and Ford trucks with the automatic transmission system. 

The Duramax Allison Transmission needs specific Automatic transmission fluid such as Dexron II E and Mercon. 

Also, the transmission system with Allison transmission can use Dexron III H or the Dexron III G.

Properties Of Advanced Automatic Transmission Fluid 

The Duramax 6.6L turbo-diesel engine is one of the leading diesel engines. With 8 cylinders, it produces enough power and torque that could tow a considerable truck. 

The Duramax 6.6L turbo-diesel with Allison Transmission, such as in the Silverado, has the best towing capacity and excellent performance due to its unique features that make it favorable. 

The transmission fluid for the Duramax Allison Transmission could be the multi-purpose Duramax synthetic fluid that helps in better performance and more torque generation.

Let us consider some of the special features of the transmission fluid for Allison’s transmission.

  • It should have anti-wear properties that make it long-lasting.
  • It should withstand extreme cold or high temperatures.
  • It should prevent the engine components from rusting.
  • The anti-foaming properties make it more durable.
  • It must be anti-shudder.
  • It should be the best-known fluid against corrosion.
  • It should make your transmission system smooth and help in the best engine performance.

Related: How to pass emissions with a deleted diesel?


Allison Transmission is found explicitly in well-known cars along with V-8, V-6, or V-4 Duramax engines such as the Chevrolet Silverado, Chevrolet B-Series, Chevrolet Kodiak, and General Motors GMC Duramax, GMC Sierra, and Hummer truck. 

The Duramax Allison Transmission requires unique transmission fluids. 

These specific fluids are designed for the Allison Transmission. For Allison Transmission, the quality of fluid is vital. 

The Allison makes sure that the fluids are tested to make them perfect for the Allison Transmission. 

The Allison-approved fluid is ideal for transmission performance and generating enough power and torque in every aspect.

Duramax Engines With Allison Transmission

All of the Duramax engines have Allison Transmission. The specification of the Allison Transmission may differ little, but the main functioning is the same.

The transmission system of different models of Duramax engine automobiles is unique and distinctive. 

For this reason, Duramax has also launched a variety of transmission fluids for specific transmissions of Duramax engines.

You can check the video for more information.

The New Chevrolet Duramax Engine And Allison Combination

The combination of the Duramax 6.6L high-performance engine with Allison transmission makes them stronger and better.

Talking about the Duramax Allison transmission before, it was a 5-speed high-performance Allison Transmission for Duramax engines, then it was changed to 6-speed, and some also had ZF6 specifications.

In most of the new high-performance Chevrolet trucks, the 6.6L Duramax engine works exceptionally well due to the 6-speed Allison 1000 transmission. 

The combination makes the heavy-duty and the pick-up trucks ideal for working and generates enough torque to move a heavy truck.  

Also, you should ensure that the transmission filter is clean, or else the transmission fluid will likely become dirty. 

The main purpose of the transmission pan and the transmission filter is to prevent the fluid from getting contaminated.

However, the towing capacity can be increased with certain changes. 

Allison 1000 Transmission 

The Allison transmission in these trucks should be Allison-approved fluids or the multi-purpose fluid for Duramax that has additives with a unique composition.

It makes them ideal for improving your vehicle’s performance when mixed with transmission fluids.

On the other hand, the unique Duramax engine of your car needs a distinct variation of lubrication. You should also ensure that the fluid level of your car is up to date.

Hence Duramax has a variety of transmission fluids for the specific transmission Duramax engines. 

However, the multi-purpose Duramax fluid capacities can be used for various high-quality cars and trucks, including Allison 1000 series transmission.

Synthetic Automatic Transmission Fluids

They offer a variety of oils for various transmissions and engines, such as 6.6 L LML Duramax, GM Duramax, and L5P Duramax. The formulation of the fluids is such to give the best results. 

The synthetic engine oil, an approved fluid, ensures that huge gasoline trucks give better mileage. 

It is anti-wear to last you long once replaced and anti-foaming. And anti-rust prolongs engine parts’ life and provides much better corrosion security. 

Synthetic fluid ensures that the oil consumption by the vehicle is reduced. 

Also, the synthetic ATF ensures a smooth drive by enabling the components of the engine to glide and move very smoothly.

Castrol High Mileage Transmission Oil

The High Mileage Castrol transmission oil can be used for vehicles with Duramax engines to give high mileage.

It has additives to prevent wear and tear of the engine parts and friction modifiers that play a crucial role in good engine performance.

It has the proper density, viscosity, and pressure handling, perfect for use in extreme hot and cold temperatures.

Castrol is the best transmission fluid when talking about the fluid type of Duramax Allison transmission.

The fluid should flow easily through the drain interval if it has the correct density. Ensure the transmission filter and pan are replaced if it gets dirty.

It provides excellent resistance against friction and prevents dust from building up.

You can ensure that the transmission fluid you use for your Allison transmission should be Allison-approved transmission fluids.

People Also Read

What Is The Cost Of The Duramax Engine?

If you plan to replace the Duramax engine, it will cost you somewhere between $15,000 and $26,000. 

Duramax is one of the leading companies for the latest engines.

However, the cost may vary depending upon the model of your car.

In Which Year Did Duramax Get The Allison Transmission?

Since 2001, Duramax has had the standardized Allison 1000 automatic transmission. 

And it was undoubtedly the best engine and transmission available back then. 

However, nowadays, there are more options available for the best engine.

Which Properties Does Allison Transmission Require?

The Allison Transmission needs fluids with the perfect viscosity, making it easier to lubricate the entire system. 

Secondly, the liquid should have thermal resistance that helps it withstand extraordinarily high and low temperatures. 

The ability to withstand pressure should also be enough in a fluid, especially when driving at high speed.

Can I Use Dexron VI In Allison Transmission?

The Dexron VI transmission fluid shall not be used for the Allison transmission, as this lubricant has a very different chemical composition.

The Dexron VI lacks the chemicals that are needed for the Allison transmission system. Allison disapproves of the use of Dexron VI strictly. 

Also, replace your transmission fluids before your fluid level decreases. 

What Is The Result Of Using The Wrong Transmission Oil For Allison?

Using the wrong transmission oil for the Allison Transmission diesel engine will be very dangerous for your vehicle.

Using the wrong or tranny fluid transmission fluid is likely to damage your Allison Transmission completely.

Once the transmission is damaged, it is likely to incur a heavy loss for your vehicle.

Can I Use Mercon V For Allison Automatic Transmission?

The Mercon V, such as Ford XT, is the high-quality transmission fluid designed specifically for the latest Ford vehicles and mercury cars.

The Mercon V is one of the ideal lubricants for the Duramax Allison transmission. It is also recommended to use for the Duramax diesel and Allison TES.

However, it is suggested to check your car’s manual to choose the specific ATF fluid for your vehicle.

Which Are The Duramax Allison Transmission Fluids?

The Duramax has high-quality engines with 6.6L capacity and V-6 cylinders along with Allison transmission; the fluid types for such transmission are specific and best quality fluids.

When choosing the Duramax Allison Transmission Fluid Type, it should be the fluid with additives and chemicals that are incompatible and specific for Allison transmission. 

It should be Allison approved and must be anti-corrosion, anti-wear, and anti-foaming, for the high performance of the Duramax Allison Transmission System.

Read More: