* Wheel balance: This is the most common and often the cheapest fix. Unbalanced wheels will cause vibrations at specific speeds.
* Tire imbalance or wear: Similar to wheel balance, uneven tire wear (cupping, feathering) or internal imbalance can cause shaking. Check the tire tread depth and look for unusual wear patterns.
* Bent wheel or rim: A bent wheel will cause vibrations, especially at higher speeds. Inspect the wheels for any obvious bends or damage.
* Worn or damaged suspension components: Worn ball joints, tie rod ends, control arm bushings, or shocks/struts can lead to shaking at specific speeds. These components affect how the wheels interact with the road.
* Driveshaft problems: A bent or unbalanced driveshaft is a possibility, though less likely to only occur at 45 mph.
* U-joints: Worn or damaged universal joints in the driveshaft can cause vibrations, especially at certain speeds.
* Transmission issues: While less common, a problem within the transmission itself could manifest as a shake at a specific speed. This is less likely to be the sole cause if the shaking is only at 45mph.
* Brake issues: Warped rotors or a sticking caliper can cause vibrations, but usually feel more like a pulsation in the brake pedal.
Troubleshooting Steps:
1. Start with the simplest and cheapest: Check tire pressure, inspect tires for wear, and get your wheels balanced. This often resolves the issue.
2. Visual inspection: Carefully examine your wheels, tires, suspension components, and driveshaft for any obvious damage.
3. Test drive: Try driving at different speeds to see if the shaking is only at 45 mph or other speeds as well. This helps narrow down the possibilities.
4. Professional inspection: If you can't identify the problem yourself, take your van to a mechanic for a thorough inspection. They have the tools and expertise to diagnose the issue accurately.
It's important to address the shaking promptly. Ignoring the problem could lead to more significant damage and safety concerns.
