For the last 20 years, GM trucks are known for their combination of Duramax diesel engines and Allison transmissions. They are known for their durability and power. In the past, GM Duramax trucks also had manual transmission but from 2007. the automatic Allison transmission is the only option.
So, do all Duramax have Allison transmissions? Yes, they do. Even the first three Duramax generations that had the manual ZF6 also had the Allison transmission. If you are thinking about buying GM trucks, you will get it with the Allison 1000 transmission.
Stay with us; you will learn everything you need to know about this transmission and how it works with Duramax. You will know all the Allison series of transmissions and, as a bonus, a lot of info on Duramax engines. Also, we will answer the FAQs that will add much information about these components.
Duramax Engine Overview
The Duramax engine came out as a co-op between Isuzu and GM. They replaced old Detroit-made diesel engines. From the start, they became the base engine for all GM trucks. They are constantly improved, and a new generation of Duramax engines comes to the market every couple of years. It is an internal combustion engine with a large following in truck enthusiast groups.
What is a Duramax Engine?
The Duramax is a 6.6-Liter V-8 diesel engine that has a block of cast gray iron. It has a deep skirt design, and its robust design is made for heavy-duty work. Two upper inches of each cylinder bore were hardened to resist cylinder wall wear.
The rest of the internal components were created to be lightweight but, at the same time, durable and robust. The crankshaft’s durability is increased so it can withstand high temperatures.
Connecting rods are made from forged steel and can endure high horsepower loads. Another innovative feature is using a high-power Bosch CP3 fuel injection pump that uses Common Rail technology.
A frequent problem of older Duramax engines is the lack of a fuel lift pump. Stock engines didn’t have problems with the lack of a lift pump. But, if you wanted to add some power to the engine, lack of high-pressure fuel became a problem. Injectors were in problem, and these engines required installing a lift pump. From the L5P engine, all Duramax engines have a factory lift pump.
All Duramax engines came supplemented with the Allison 1000 transmission. At the start, the Duramax LB7 had an automatic 5-gear Allison transmission. From late 2004. they switched it to a 6-gear Allison automatic transmission. Duramax & Allison experts agreed that switching to a 6-gear transmission is great. Also, LB7, LLY, and LBZ were offered with the manual ZF6 transmission.
Types of Duramax Engines
The most common choice for truck shoppers is Duramax 6.6L engines. Some newer Duramax engines come with 2.5L, 2.8L, and 3L displacements. But Duramax is best known as a large 6.6L engine for diesel truck owners. There are 7 types or generations of Duramax engines with 6.6L displacement:
- LB7. It was made between 2001 and 2004.
- LLY. Production dates between 2004 and 2005.
- LBZ is made between 2006 and 2007.
- LMM. Production period between 2007 and 2010.
- LGH. An engine that was long in production between 2010 and 2017.
- LML. Made combined with the LGH between 2011 and 2016.
- LP5. Currently in production that started in 2017.
There are also smaller Duramax engines that also showed great performance. Those are the 2.5L XLD25, 2.8L XLD28, and LWN 2.8L engine. There are also newer 3.0L engines marked as LM2 and LZ0. All these engines are also a frequent choice for truck buyers.
What is worth of note is that all these engines come combined with the Allison 1000 transmission. Only the first three 6.6L engines have an option of a manual ZF6 transmission.
Features and Benefits of Duramax Engines
All Duramax engines are known as strong and dependable engines. They offer a lot of stock horsepower and torque and can be used for different purposes. Today’s truck mentality is closely connected with GM lighter-duty trucks combined with Duramax engines and Allison transmissions.
All these engines were used in multipurpose trucks. They could be used for towing, drag racing, or used as a regular truck. The Duramax is the best option for truck owners that want to create high-power trucks. They can handle a lot of added horsepower and torque.
Also, the transmission requires some improvements, especially the clutch. But, with these improvements, you can make a competition truck for truck enthusiasts.
Allison Transmission Overview
The Allison transmission company was founded back in 1915. They were quickly switched to making parts for the military planes. After the war, the GM giant needed a proven transmission maker, and they bought the Allison in 1928. It was under GM until 2007. when they sold Allison to Onex Corporation.
What is an Allison Transmission?
The Allison transmission is used in many different vehicles, from cars, lighter-duty trucks, and larger trucks to work machines and buses. The Allison transmissions are fully automated. Depending on the make and the model, they offer up to 10 gears.
Check Out Building The BADDEST Allison Transmission Ever On YouTube! FULL BREAKDOWN:
Types of Allison Transmissions
The Allison transmissions are grouped by the series. Each series has its purpose and use on the market.
- Allison 1000. These are designed for light commercial vehicles. They can have up to 6 gears and 2 overdrives.
- Allison 2000. The application and features are the same as for the 1000 series
- Allison 3000. They are used in medium-duty trucks and commercial vehicles. They also have up to 6 gears, 2 overdrives, and they can handle up to 450 horsepower. Their design allows them to be fuel efficient in various vehicles.
- Allison 4000. This is an advanced transmission option for light commercial vehicles. They offer up to 7 gears and 2 overdrives. They can withstand up to 800 horsepower. This series offers high performance and fuel efficiency. This comes at a price, so don’t be shocked by a price of at least $3,000.
Besides these series, Allison offers transmission for off-highway machines and vehicles.
- Allison 5000. This heavy-duty transmission is used in oil field equipment, tractors, cranes, and dump trucks. They can sustain an engine output of 670 horsepower.
- Allison 6000. This series of transmissions are used for military vehicles, construction and mining equipment, and agriculture mechanization
- Allison 8000. This high-end transmission is utilized in oil derricks and cranes and can support up to 1.200 horsepower
- Allison 9000. This Allison supports the most advanced and demanding off-highway trucks and machinery working in extreme conditions. This transmission can support up to 2.600 horsepower.
Features and Benefits of Allison Transmissions
Allison transmissions have been used for 20 years, just on GM trucks. They are dependable, and they can handle a lot of power. They have proved their worth by just looking at the number of vehicles with that transmission on the roads. Most HD trucks have this transmission.
The only downside of these transmissions is that they cannot withstand too much-added power at least with the stock components. If you add more than 200 horsepower, you must change the clutch packs and the torque converter.
Which Duramax Engines Come With Allison Transmissions?
All Duramax engines come with an Allison transmission. ZF6 manual transmission has been out of the picture for a long. The only option for your GM truck is the automatic Allison transmission.
Explanation of Why Some Duramax Models Do Not Have Allison Transmissions
The first three generations of Duramax engines, the LB7, LLY, and LBZ, had an option of pairing up with manual transmission. In those years, automatic transmissions overflowed the market, and since then, most vehicles are using them.
The automatic transmissions had many revisions, offering ease of use and great functionality. That came with a price. Automatic transmission is generally more expensive, and maintaining it is pricier.
Also, the manual transmission allows the driver to control the engine power output. This option is great in some situations, like when towing heavy loads. But, the sheer ease of use of the automatic transmission was enough to switch most Americans from the manuals.
Can You Add an Allison Transmission to a Duramax Engine?
Every Duramax comes with the stock Allison Transmission. The exceptions are the first three Duramax engines that could be bought with the manual ZF6 transmission.
Pro Tip: You can also upgrade the 5-gear Allison transmission and add one more gear with the help of a conversion kit.
Possibility of Adding an Allison Transmission to a Duramax Engine
All Duramax engines came with the Allison 1000 transmission, so there is no choice. When you buy a GM truck, you will get an Allison. The only thing is that you can work on it to make it better for your needs.
Benefits of Having an Allison Transmission with a Duramax Engine
The combination of a Duramax engine and an Allison transmission proved to be the best deal over the years. Chevy HD truck owners know this the best. Combining these components guarantees the best performance, tremendous durability, and fuel efficiency.
You can also improve both the engine and transmission. There are different kits and options for improving torque, power, or even fuel efficiency. You can modify your truck to meet your needs. Do you want a towing truck? That is not a problem? A drag race truck? Of course! Or, you can have a regular truck with lower fuel consumption. All that can be found on the market.
Do All Duramax Have Allison Transmissions: FAQs
What type of Allison Transmission Does the Duramax Diesel Have?
Every Duramax-powered truck comes with the Allison 1000 transmission. The first Duramax, LB7, had a 5-gear, Allison. After that, all newer Duramax engines are paired up with 6 gear Allison 1000 transmission.
Who Builds the Duramax Engine?
The Duramax engines are made in Moraine, Ohio, by the joint venture of Isuzu and GM, called DMAX. The ownership is divided into 60-40 shares, with GM owning the majority.
When Did GM Stop Using the Allison Transmission?
The 2017-2019 LP5 Duramax truck owner is the last owner of a Duramax truck with actual Allison transmission. From 2020. the GM trucks use 10-speed Allison branded transmission made by GM.
Final Considerations
The Duramax engines made a revolution in the truck market. With them, GM got reliable and robust engines. They are paired with an outstanding stock Allison 1000 transmission. Initially, the trucks used 5-speed Allison but quickly switched to a 6-speed transmission.
This combination can sustain some limited boosting without changing any stock parts. But, if you want to add real power to your truck, you must invest more in both engine and the transmission.
From 2020. the GM is using its own 10-speed transmission branded as Allison. They still have to prove their worth. The original Allison is a proven transmission that will fulfill most of your needs.
