What was found
R GEN OFF CAUTION WITH ASSOCIATED R HYD ELEC 2, R UTIL BUS, AND L UTIL BUS ADVISORIES AT 40 KTS DURING TAKEOFF JUST AFTER PRESSING THR BUTTON FOR TAKEOFF THRUST. REJECTED, RAN QRH AND CAUTIONS CLEARED. COORDINATED WITH GOC AND MOCCASIN TO CONTINUE. ALL INDICATIONS RETURNED DURING SUBSEQUENT TAKEOFF AT ROTATION. QRH DID NOT PERMIT ANOTHER GENERATOR RESET AND REQUIRED LAND AT NEAREST SUITABLE AIRFIELD. DECLARED EMERGENCY AND CONDUCTED AIR TURN BACK TO KMEM. REMOVED AND REPLACED #2 IDG ( PN: 727792M SN: A0161 MANUFACTURER: UTC AEROSPACE SYSTEMS) REF AMM 24-11-01-4. LEAK AND OPS CHECKED GOOD REF AMM 24-11-00-5.