O'Fallon Auto Repair

The Dog Clutch: The Brutally Effective Heart of Your Manual Transmission In the world of automotive engineering, most components are designed for smooth, quiet, and seamless operation. But there's one component in many manual transmissions that is, by design, the complete opposite: the dog clutch. Its name might sound odd, but its purpose is pure, unadulterated performance. If you've ever driven a high-performance car with a lightning-fast, rifle-bolt shifter, you've experienced the work of a dog clutch. For driving enthusiasts in O'Fallon who appreciate the mechanical connection of a manual gearbox, understanding this component reveals why some transmissions feel so incredibly direct and robust. Let's dive into what makes it so special and so demanding. What is a Dog Clutch? The "Clunk" You Can Feel First, let's clear up the name. It's not named after man's best friend, but rather the "dog teeth&q ... read more

What Engine Knock Is and How Your Car Fights Back You’re accelerating up an on-ramp to I-70, your engine is under load, and then you hear it, a rapid, pinging, metallic rattle from under the hood that sounds like a handful of marbles being shaken in a tin can. This isn't a normal engine sound; it's the sound of self-destruction. This is engine knock (or detonation), and it's one of the most destructive forces your engine can experience. For drivers in O'Fallon, where highway merges and towing are part of daily life, understanding knock is key to protecting your investment. At Hillside Auto Repair, we know that the most important battles your engine fights are the ones you never hear, thanks to a tiny but mighty guardian: the knock sensor. What is Engine Knock? The Unwanted Explosion To understand knock, you first need to understand normal combustion. In a healthy engine, the spark plug ignites the air-fuel m ... read more

From Smog Pumps to Supercomputers: The 50-Year Journey to Cleaner Air If you've ever had the pleasure of tuning up a classic American V8, you've likely encountered a Rube Goldberg-esque network of vacuum hoses and a curious belt-driven device known colloquially as the "smog pump." For gearheads and history buffs in O'Fallon, this piece of 1970s engineering represents a pivotal moment—the automotive industry's first concerted response to a growing environmental crisis. At Hillside Auto Repair, we believe that understanding where we've been is key to mastering where we are today. The journey from simple smog pumps to the complex emissions systems in your modern car has fundamentally shaped our industry, our vehicles, and the very air we breathe. Let's take a ride through the decades. The First Gasp: Early Emissions Systems Before federal mandates, the automotive industry was largely focused on performance an ... read more

You're driving down a familiar O'Fallon street, maybe along Highway K or Tom Ginnever Ave, and you hit a bump, pothole, or even a dip in the road. Instead of absorbing the impact smoothly, your steering wheel suddenly jerks in your hands. For a split second, it feels like your car is trying to steer itself. This unnerving sensation isn't a ghost in the machine; it's a classic case of a mechanical issue known as bump steer. At Hillside Auto Repair, we know that confidence in your vehicle's handling is non-negotiable for navigating our local roads. This post will demystify bump steer, explaining what it is, what causes it, and—most importantly—how to fix it to restore safety and peace of mind to your drive. What is Bump Steer? In technical terms, bump steer (or roll steer) is the unwanted and unexpected steering effect that occurs when a vehicle's wheels move vertically up and down (as they do when hitting a bump) without a ... read more

If you think your car is just a collection of mechanical parts, it's time for a software update. Modern vehicles, from the Chevys and Fords cruising down I-70 to the family SUVs navigating the streets of O'Fallon, are essentially rolling computers. And just like any network, these computers need to talk to each other. This conversation is happening billions of times a day, silently and invisibly, thanks to a brilliant innovation called the Controller Area Network, or CAN Bus. Think of the CAN Bus as your car's central nervous system. It’s the high-speed digital highway that allows every electronic control unit (ECU) in your vehicle to share information seamlessly. A Party in Your Powertrain: How the CAN Bus Works Imagine a massive, well-organized party. The engine control module (the life of the party) needs to tell the transmission how fast it's spinning. The anti-lock braking system (the cautious friend) needs to alert the traction contro ... read more