--- title: "Over-Revved Truck Engine Sends Every Piston Through the Block, Obliterates Transmission" description: "While driving downhill, a truck driver's transmission shifted into first gear, overrevving the engine and blowing it up." date: "2023-05-14" modified: "2023-05-14" authors: - name: "Nico DeMattia" job_title: "Contributing Writer" link: "https://www.thedrive.com/authors/nico-demattia" url: "https://www.thedrive.com/news/over-revved-truck-engine-sends-every-piston-through-the-block-obliterates-transmission" categories: - "News" tags: - "Jeep" - "suv/crossover" - "Wrangler" --- # Over-Revved Truck Engine Sends Every Piston Through the Block, Obliterates Transmission ![]() Anyone with even the slightest shred of mechanical sympathy has to wince at videos like this one. *[Redditor Conyers117]()* recently posted a video of a [diesel ]()engine from an International DuraStar work truck that was overrevved while going downhill and quite literally exploded, taking its Allison transmission with it. According to *Conyers117*, the truck belonged to an electrical company and, while the driver was going down hill, its transmission somehow shifted into first gear. That immediately overrevved the diesel engine, which broke every rod and and piston, firing them through both sides of the engine block. Part of the transmission bellhousing also turned to shrapnel and, luckily for the driver, blew through the only passenger floor, even destroying a window. It's unclear exactly what kind of truck it was, which engine is had, or how fast it was going downhill, so it's impossible to know how high the revs got before the engine turned into a frag grenade. Unfortunately, the engine's ECM was another victim of the obliteration, so the mechanics weren't able to find out how fast it went before detonation. https://www.reddit.com/r/Justrolledintotheshop/comments/13f6l2u/turns_out_if_you_try_hard_enough_you_can/ You might be quick to point to driver error, and that's certainly possible. However, according to *Conyers117*, the truck used an Allison automatic transmission, so it shouldn't have allowed a first gear downshift at speed. The driver also said the transmission did it on its own, so the thinking is that there was an issue with the transmission itself and not driver error. Although, that does sound like a six-year-old's excuse when something breaks—"It did it all by itself!" This isn't as egregious as the driver that [flat-towed ]()a 2021 [Jeep ]()Wrangler in four-low and first gear. That was just ignorance, which sent a Pentastar V6 revving to an estimated 50,000 rpm, before it relieved itself of its pistons. At least in this case, the transmission's TCM shouldn't have allowed a first-gear shift, even if the driver tried to manually, so the driver could be off the hook. *Got tips? Send 'em to tips@thedrive.com* ## Author Nico is a writer and reviewer from New Jersey who probably thinks he’s a lot funnier than he actually is. His love of cars began when he was just a kid playing Gran Turismo 3, grinding out enough race wins with a Mazda Miata to save up for an in-game RUF 911. That passion for small, lightweight sports cars drove his desire to learn more about the industry, get his hands on as many cars as he could, and bring those experiences to life on the page. He cut his teeth writing about BMWs, Volkswagens, and Audis, mostly, and has owned far too many of each. He’s on his fourth 3 Series sedan, but all of his old, cheap German cars have forced him to learn more about car maintenance than his mechanical capability can handle. Too many late nights have been spent scrambling to get a car running by morning so he could get to work. For some reason, he never seems to learn that old Bimmers probably aren’t the best daily drivers. But he loves more than just old German cars. He’ll gladly drive and discuss anything with four (or even three) wheels. Cars aren’t his only passions, though. Nico is also a big nerd and loves movies, video games, comic books, and cares far too much about the New York Giants. So don’t be surprised if you see football references or dumb, obscure movie quotes in any of his car reviews. ### Author social links [Instagram]() [LinkedIn]()