If you overload your dryer you may be asking for trouble. Putting too many clothes in your dryer may actually damage it and possibly burn out the dryer motor.
If your dryer shakes, vibrates, rattles or even tries to move around the room, it could be that the legs on the dryer are uneven or the floor surface is unstable but most likely it is because you have over loaded it, too many clothes!!
A number of dryers have different settings and cycles for a variety of times, fabrics and item options. If you use the Air Dry or Air Fluff cycle and it leaves your clothes damp it is because not enough heat was produced to dry the clothes, using the wrong cycle and time setting can leave the clothes damp, also piling too many clothes into the dryer will prevent the clothes from tumbling freely and therefore prevent them from drying. If the dryer has a dryness sensor the sensor may overload if the clothes are not able to dry adequately. The sensors then would malfunction or stop working.
The dryer motor could possibly burn out prematurely if you continue to overload it because it puts a strain on the dryer.
If you are overloading your dryer on a regular basis, that can eventually cause the system to overheat and cause damage to the unit.