What Causes One Wheel to Spin While the Other Doesn't in a Front-Wheel Drive Car?
2 Answers
The majority of sedans are front-wheel drive. If you jack up one wheel and the other doesn't spin, this is a normal phenomenon. Similarly, in real-world scenarios, if one wheel is stuck in mud and slipping, the other wheel may remain completely stationary. Between the two drive axles of a car, there is a device called a differential, whose function is to specifically regulate the rotational speeds of the two half-shafts. When one wheel encounters significant resistance—for example, during a right turn, the right wheel experiences increased resistance and slows down—the four planetary gears mounted on the cross-shaft inside the differential will rotate to accommodate the reduced speed of the right half-shaft. Without this differential design, the right half-shaft could potentially snap. The same principle applies during left turns. Therefore, on special road surfaces (such as ice or muddy roads), it is normal for one wheel to spin while the other doesn't, due to the action of the differential. If the car's differential is damaged, minor issues may include abnormal noises from the vehicle, noticeable jerking during acceleration or deceleration, and significant resistance felt during turns. If the differential is severely damaged, the two drive half-shafts may become rigidly connected, causing both wheels to rotate at the same speed (making turning impossible) and potentially rendering the car undrivable.
I've been in the automotive repair business for many years, and it's extremely common to encounter situations where one wheel of a front-wheel-drive vehicle spins while the other doesn't. This is usually due to a faulty differential. The differential is responsible for allowing wheels to rotate at different speeds during turns, but when it's stuck or damaged, it can restrict the rotation of one wheel. A broken axle shaft is another major cause. The axle shaft connects the powertrain to the wheels, and if it breaks, power can't be transmitted. Brake system issues like seized calipers or damaged brake rotors can also lock up a wheel. During inspections, I first lift the vehicle with a jack to test each wheel's rotation flexibility. If there's noticeable resistance, it might indicate stuck brake components. If there's no power at all, it's likely a drivetrain issue. Differential oil leaks or electronic sensor failures can also cause similar problems. Avoid forcing the vehicle to drive to prevent further damage, and take it to a professional shop for technician diagnosis. Regularly changing transmission fluid and inspecting brake pads can help prevent such failures.
