Why Does My Car Shake At 60 But Not 70

Why Does My Car Shake at 60 mph But Not 70 mph? Troubleshooting the Wobble

Experiencing a shake or vibration in your car at a specific speed, like 60 mph but not at 70 mph, can be unsettling. This isn't just an annoyance; it could indicate a problem requiring attention. This article will explore common causes for this specific symptom, helping you diagnose the issue and potentially save yourself a costly repair bill. Ignoring the problem can lead to further damage and safety concerns.

Possible Culprits Behind the 60 mph Shake

The fact that the shaking occurs at 60 mph but subsides at 70 mph points towards a resonance issue – a frequency at which a component vibrates intensely. Let's examine some of the most likely culprits:

1. Wheel Balance Issues

This is often the first and most common suspect. An imbalance in one or more wheels means the weight isn't evenly distributed. At 60 mph, the rotational speed hits a resonant frequency, causing the shaking. Increasing speed to 70 mph might shift the frequency out of the resonant range, making the vibration less noticeable. Uneven tire wear can also contribute to this problem.

• Symptom: Noticeable shaking in the steering wheel.

2. Tire Problems: Cupping, Bulges, or Worn Tires

Uneven tire wear, such as cupping (irregular wear patterns), can create vibrations at certain speeds. A tire bulge – a localized swelling – can also cause similar symptoms. Worn-out tires, generally, will exhibit more pronounced vibrations as speed increases, but a severe case could manifest like this.

• Symptom: Shaking might be accompanied by unusual tire noise or handling difficulties.

3. Wheel Alignment Problems

Improper wheel alignment can result in vibrations, particularly at higher speeds. If your car's wheels aren't correctly aligned, the tires will contact the road unevenly, causing a shake. This is less likely to be speed-specific like your problem but is still worth investigating.

• Symptom: Uneven tire wear, pulling to one side, and difficulty maintaining a straight line.

4. Damaged Drive Shaft or Axle

A damaged CV joint (Constant Velocity joint) in your drive shaft or axle can cause vibrations that are more noticeable at certain speeds. This is a serious issue requiring professional attention.

• Symptom: Clicking or popping noises, especially when turning.

5. Brake Rotor Warping or Issues

While less likely to be specifically speed-dependent, warped brake rotors can contribute to vibrations, particularly when braking. If the vibration only occurs while braking at around 60 mph, this is a more plausible culprit. Check your rotors for scoring or uneven surfaces.

• Symptom: Pulses in the brake pedal when braking.

Diagnosing the Problem

While this article provides potential causes, a definitive diagnosis requires a hands-on inspection. Here are some steps to take:

1. Visual Inspection: Carefully inspect your tires, wheels, and brakes for any visible damage.
2. Professional Check: Take your car to a trusted mechanic or tire shop for a thorough inspection and balancing. They possess the equipment (like wheel balancing machines) to pinpoint the issue.
3. Rotation and Alignment: Even if balancing solves the issue, consider getting a tire rotation and wheel alignment check. This preventative maintenance can extend the life of your tires and improve your car's handling.

Avoiding Future Problems:

Regular maintenance is crucial for preventing issues like this. This includes:

• Tire rotation and balancing: Typically every 5,000-7,500 miles.
• Wheel alignment checks: As needed, especially after hitting a pothole or experiencing rough road conditions.
• Brake inspection: During regular maintenance checks.

By understanding the potential causes and taking proactive steps, you can keep your car running smoothly and safely. Remember, a seemingly minor vibration can be a warning sign of a more significant problem. Don't ignore it!