If a stackable washer dryer unit is vibrating it may not be level.
Dryer vibration on floor.
I haven t tried this yet.
A damaged idler pulley idler pulley bracket or idler pulley tension spring could.
My again non physics expert mind s theory is that this spreads the vibration load out to more planes points of contact.
Noise from the dryer often means that a hard object is clanging around inside the drum the zipper on a sweatshirt change left in a pocket your phone.
If the contents of the drum check out okay then a bad drum support roller could be causing a thumping noise.
Regardless of the specific problem vibration is definitely a problem that you ll want to address since the movement can cause damage to surrounding walls and floors as well as the dryer itself.
If it s not possible to add bracing as described you can place a 5 8 or 1 inch sheet of plywood under.
This will only work of course if your washer sits close enough to the wall on one side and the dryer on the other.
If the laundry appliances are on the main floor and adding bracing in the ceiling of the level directly under the washer is possible this should give the washer a sturdier stable floor and minimize vibrations.
Multiple issues can cause a dryer to vibrate and make a lot of noise from an overloaded dryer to a defective component.