* Unbalanced or damaged tires: This is the most common cause. An imbalance will cause vibration at certain speeds, and damage (like a bulge or uneven wear) will worsen the effect, especially under acceleration when more force is applied to the tires.
* Bent or damaged wheel: Similar to unbalanced tires, a bent wheel will cause vibrations, especially noticeable under acceleration.
* Worn-out wheel bearings: As wheel bearings wear, they become less smooth, leading to vibrations that increase with speed and especially under load (acceleration).
* CV joint problems: Constant velocity (CV) joints transmit power from the transmission to the wheels. Worn or damaged CV joints are a common cause of vibration, particularly under acceleration, and often manifest in the 35-45 mph range. A clicking sound might accompany the shaking.
* Driveshaft problems: While less likely if the shaking is isolated to 35-45 mph under acceleration, a problem with the driveshaft itself could contribute to vibrations.
* Engine mounts: Although less directly related to the wheels, worn engine mounts can transmit engine vibrations more strongly to the chassis, which could be felt as a shake at certain speeds under acceleration.
* Brake rotor warping: While less likely to only happen during acceleration, warped brake rotors can cause vibration, especially when braking, but sometimes it can be felt during acceleration as well.
Troubleshooting Steps:
1. Start with the simplest: Have your tires checked for balance and condition. This is the quickest and most cost-effective check.
2. Check wheel bearings: A mechanic can easily check for play in your wheel bearings.
3. Inspect CV joints: Look for cracks, tears, or excessive play in the CV joints. This usually requires a mechanic.
4. Professional Diagnosis: If the simpler checks don't reveal the problem, take your car to a qualified mechanic for a proper diagnosis. They have the tools and expertise to identify the specific issue.
It's crucial to address this issue promptly. Ignoring a shaking car can lead to more serious damage and potentially unsafe driving conditions.
