The problem is a worn out trust bearing.
To replace it, you have to complete the following actions: Turn off the electrical power supply. Remove the control knob by pulling it. Unscrew the mounting bolt as seen on the picture.
4. Remove the control panel by shifting it upwards as seen on the picture
5. Place the control panel on top of the dryer as seen on the picture and unscrew two bolts marked by red arrows on the illustration below.
6. Unscrew two bolts marked by arrows on the picture below. Remove the front panel with the thrust bearing attached to it by pulling it by the bottom part. Don’t forget to disconnect the corresponding wires.
7. Unscrew two bolts as seen on the picture and remove the worn out part.
It looks like this
Here is a new part next to the old one. Deterioration is obvious.
8. Install the top part of the thrust bearing.
9. Then the bottom part.
Assemble the appliance back together in an opposite order. A repair like this usually takes an hour. It is recommended to vacuum the inside of the dryer in order to remove the lint and dust while the appliance is disassembled.