Car shaking

It can have a speed which it feels most "Amplified" at, this is known as resonant frequency.

Another culprit that tends to cause vibration or wheel shudder at certian speeds are the front axle constant velocity joints. Even without the hubs engaged thay will cause vibration.

Aside from the tires being out of balance, those are the most likely scenarios.

Bad axles also will click when making a tight u-turn at low speeds and can have problems if you have raised or lowered the trucks' suspension as they are sensitive to chagnes in their length.

It could cause it as well as tire balance.