Check the contacts of your contactor for signs of overheating. Replace as necessary. Check the tightness of the reversing valve solenoid coil if you have a reversing valve and tighten as necessary. Check for the casing vibrating and adjust/tighten as necessary. Check for any components including refrigerant lines rubbing along casing or bottom of unit. Check fan blade hub and ensure blade is tight on hub. You can disconnect the fan motor wires (tape off the leads to prevent short) and run the unit for a minute to see if the vibration exists without the fan motor running.
I hope you find these suggestions to be very helpful moving forward.
Answers & Comments
Check the contacts of your contactor for signs of overheating. Replace as necessary.
Check the tightness of the reversing valve solenoid coil if you have a reversing valve and tighten as necessary.
Check for the casing vibrating and adjust/tighten as necessary.
Check for any components including refrigerant lines rubbing along casing or bottom of unit.
Check fan blade hub and ensure blade is tight on hub.
You can disconnect the fan motor wires (tape off the leads to prevent short) and run the unit for a minute to see if the vibration exists without the fan motor running.
I hope you find these suggestions to be very helpful moving forward.