B737-800
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Diverted; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
Enroute to ZZZ1 at FL340; both Captain and First Officer FMC issues developed into a situation where the navigation to points became unreliable. Autopilot frequently disengaged; safe operation into ZZZZ1 with IFR operations could not be accomplished. Referenced QRH for FMC fail; non-routine landing; and overweight landing checklists. Priority handling was requested; decision was made to divert to ZZZ2 with VFR conditions; and long runway to perform overweight landing. Landing ZZZ2 uneventful; aircraft taken out of service. Photos of FMC values and indications which may have affected navigation attached.
B737 Captain reported a dual FMS failure resulted in a diversion.