As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLT FLT 1845 EN ROUTE PHL TO FPO - AIRFRAME VIBRATION WAS FELT AT FL 320 AND HIGHER SPEEDS. A DECISION WAS MADE TO DIVERT TO CLT. VIBRATION STOPPED BELOW 18,000 FEET AND SLOWER SPEEDS. FLIGHT LANDED IN CLT WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED 3 ELEVATOR SERVO ROD ENDS. OK FOR SERVICE.