When the Allison 10-speed transmission (10L1000), found in GM heavy-duty trucks, was released, it was touted to be the strongest, most well-engineered transmission bolted behind the Duramax engine. I’m not here to argue that statement, but even so, the Allison 10-speed is still known to have a few shortcomings regarding durability and reliability, especially when larger tires and added power are thrown into the mix.

Because of that, we need to find ways to upgrade the Allison-10 speed to significantly enhance the performance, durability, and efficiency of this electronically controlled, totally computerized gear changer. There are many ways to upgrade the transmission, and they range from simple bolt-on items to complete rebuilds. We knew we needed to call the experts, so we reached out to Next Gen Drivetrain which specializes in upgrades for the Allison 10-speed transmission as well as all other diesel truck transmissions.

Next Gen Drivetrain has developed multiple lines of transmission valve bodies, upgrade kits, and even complete transmissions designed to support everyone from rigorous hot shot haulers to Sunday drivers, and even all-out racing applications. Not only are they Allison 10-speed transmission experts, but they are equally adept at the LCT Allison, 48RE, 68RFE, Aisin Seiki, TorqShift, and many many more. When it comes to creating transmission-upgrade parts, their engineering department is 100-percent in-house. So, when we reached out to them seeking some information they were happy to help.

Allison 10-Speed Torque Converters, Reliable Or Not?

After speaking with Nate Valentin, the head of engineering behind their valve body upgrade kits, drums, and other upgrades, we were informed of what truly goes wrong in these complicated transmissions. Our first question was about the transmission’s torque converter. For those who may not know, this is the fluid coupling system at the front of the transmission designed to manage torque coming out of the engine. The Allison 10-speed features a rather robust — but not perfect — torque converter from the factory.

Upon further discovery, the folks at Next Gen Drivetrain have seen some units where the clutch system inside the torque converter burns up. Come to find out, this is usually not the torque converter’s fault, but rather, a hydraulic issue, usually the valve body, making it difficult for the converter clutch to get the fluid pressure and lubrication it needs to run properly. They informed us that transmissions with upgraded valve bodies very rarely suffer torque converter failure, even with added power due to the hydraulic modifications made to the valves, separator plate, and spring rates.

Burnt Clutches, Will it Happen To You?

Nate explained that the Allison 10-speed transmission is basically a huge 10L80-E, the transmission found in the Camaro/Silverado 1500. It actually has almost no mutuality with the six-speed Allison of yesteryear. You could call this transmission an “Allison-In-Name-Only.” So, to better understand this transmission’s shortcomings, it would be helpful for us to look at its little brother, the 10L80-E. These transmissions suffer from the same dreaded “E” clutch failure that the smaller 10L80-E does, where the clutches become overpowered and begin to slip during high-stress situations such as heavy towing or when used in tuned vehicles.

Next Gen Drivetrain informed us that although these clutches are easy to overpower in certain applications, this is again prevented for most people by simply improving the valve body. They stressed that the number one issue in these transmissions is the hydraulics, and again, specifically the valve body. That means, 10-speed Allisons featuring their valve bodies very rarely incur damage to the clutches inside the case, even with added power. It certainly sounds like valve bodies are the source of this transmission’s troubles.

Transmission Valve Body – The Soul Of The Issue

The transmission valve body is the control center for everything that happens. It is responsible for directing hydraulic fluid to the appropriate clutches to facilitate gear shifts, as well as diverted lubrication to gears, shafts, bushings, and bearings. It comes as no surprise that upgrading the valve body with performance-enhancing/reliability-enhancing modifications can optimize shift timing, firmness, power to the ground, and overall transmission response.

Next Gen Drivetrain’s high-performance, reliability-built valve bodies typically feature improved valve materials favoring polished billet valves in all wear-prone areas, new solenoids, and enhanced calibration to deliver crisper, more precise shifts. Additionally, some aftermarket valve bodies offer programmable features, allowing drivers to customize shift points and patterns according to their driving preferences.

To upgrade the Allison 10-speed valve body, Next Gen Drivetrain offers both a DIY valve body kit that allows you to build a better unit yourself, right in your own driveway, or a complete valve body that is ready to put into place. The Project Carbon 10L1000 valve body comes with a new oil pump, allowing truck owners to create higher pressure without modifying the computer. The valve body and oil pump combination are designed to deliver practicality and performance. What’s more, this kit can be installed without removing the transmission. And in case you were wondering, Next Gen Drivetrain valve bodies feature a lifetime, unlimited mileage warranty.

Why the combination of parts? The valve body is not the part of the transmission that produces pressure, the pump does. The reason the valve body is critical in producing pressure is because its cast design allows the largest leak point in this transmission. Project Carbon valve body assemblies eliminate these concerns permanently. Further, these products are all designed to operate without having to modify the TCM tuning on the vehicle, making install a breeze.

Maintain Your Allison 10-Speed Transmission

We asked our friends at Next Gen Drivetrain the best way to keep the Allison 10-speed transmission healthy for the long run. Aside from the obvious valve body upgrade, they stressed that maintenance is key. Neglectful maintenance will dramatically shorten the life of a transmission, and fluid should be changed every 30,000 miles or so for the average person.

Easy Ways To Extend The Life Of Your Transmission

• Perform Timely and Proper Maintenance
• Minimize Average Operating Temperature (AOT)
• Avoid High-Stress Applications
• Keep your Torque Multiplication Factor (TMF) Down

Upgrading the Allison 10-speed transmission will allow you to realize the full potential of this transmission without the constant concern about reliability. Whether you’re a weekend warrior hauling heavy loads or a performance enthusiast seeking sharper shifts and crisper throttle response, these upgrades can transform your driving experience and ensure your transmission performs at its best for miles to come.

You can find many more upgrades and information about the Allison 10L1000 transmission by checking out the Next Gen Drivetrain website.