What was found
ON CLIMBOUT OF LAS EN ROUTE FOR SFO AT FL 190 NR 1 ENGINE OIL PRESSURE DROPPED TO 10 PSI, FOLLOWED QRH AND SHUTDOWN NR 1 ENGINE, TURNED BACK TO LAS AND LANDED WITHOUT FURTHER EVENT. MAINTENANCE REMOVED AND REPLACED NR 1 ENGINE OIL PRESSURE TRANSMITTER IAW BMM 79-032-011-4, OPERATIONAL CHECK OF OIL PRESSURE INDICATING SYSTEM WAS GOOD. VENDORS INCOMING FUNCTIONAL TEST OF OIL PRESSURE TRANSMITTER S/N 2516 CONFIRMED REASON FOR REMOVAL FOR ERRATIC OPERATION. DISASSEMBLY OF UNIT FOUND SYNCHRO BRUSHES BURNT, ARBOR TEETH WORN, AND A DEFECTIVE SOLDER STRIP. REPLACED DEFECTIVE PARTS AND OVERHAULED UNIT IAW CMM 31-59-1.