3 TRANSMISSION TEMPERATURE SHOULD BE ABOUT THE SAME AS ENGINE Pictured at the right is a custom stator that Goerend uses for Allison converter applications. The factory stator can develop hairline cracks even at lower horsepower levels, which can turn into a big problem. We started our tour off looking at some of the biggest weaknesses of the Allison 1000, which lie in the factory torque converter. Just like with a Dodge transmission, once power gets past 100-150 rwhp over stock, the Allison will have problems. While the Allison 1000 does indeed have one of the strongest geartrains of any diesel transmission, it runs into the same converter and clutch slippage issues as other transmissions as the power is raised. We hate to give a “maybe” answer on a yes or no question, but it’s actually the closest to the truth. Or in the case of very large turbos, where the engine is trying to struggle up in the rpm range, it might not spool at all! 2 THE ALLISON 1000 IS THE STRONGEST DIESEL TRANSMISSION:

Since the input torque with two differently sized turbos will be different at nearly every rpm point, a converter that stalls at 2,200 rpm on one truck might stall at 2,500 rpm on another. Since stall speed is calculated from engine torque at a specific rpm, a converter that’s used on a truck with a 62mm turbo will react much differently than if the truck has an 80mm turbo. One converter that spools a large turbo on a 6.7L might not work the same on a 5.9L. A converter that stalls at 1,800 rpm on one engine may stall at 2,200 rpm on another. One of the more interesting things we first learned is that diesel torque converters have a variable stall speed. 1 A DIESEL TORQUE CONVERTER HAS A GIVEN STALL SPEED: In the end, after two days of tours, questions, disassembly, and reassembly, we left with a much greater understanding of how transmissions worked, what is fact, and what is fiction. Since torque converters are his specialty, we also grilled him on the ins and outs of fluid coupling.

Goerend has more than a decade of experience, and we thought this would be a good chance to pick his brain concerning some common facts and fallacies we hear regarding Allisons, Dodge 47s and 48s, and transmissions in general. Now he’s behind the scenes, making torque converters, valve bodies, and testing various combinations on a state-of-the-art transmission dyno. After starting a speed and repair shop in the ’80s, he progressed to transmissions, then diesel transmissions, which exploded his business.

Lucas, Iowa (population 140), he has been in the diesel transmission game as long as anyone. Even though Goerend is located in the tiny town of St. While Diesel World Editor Adam Blattenberg was over getting a crash course in Ford transmissions at, yours truly swung by Northern Iowa to talk with one of the masterminds of GM and Dodge transmissions, Dave Goerend. Dissecting the Allison 1000, Dodge 47/48, and Torque Converters with Dave Goerend

Allison transmission in dodge cummins