Making vibration

Hello
See manual link below for a for model #DLEX7600. They have not changed . Here are some vibration possibilities.
1) Make sure the dryer is on a solid base floor that is level.
2) Make sure the dryer is level, check leveling legs if not.
3) Check your drum rollers on page #74 in the link below. If the drum roller bearings are worn, the unit will vibrate. There are thee rollers that hold your drum.
4) If your blower housing assembly get impacted with lint, you will get a vibration from the blower wheel. See page #73 in the manual link below.