What was found
GEAR DISAGREE WARNING WITH TRIPLE CHIME AFTER TAKE OFF. C/W QRH, DECLARED EMERGENCY, AND RETURNED TO MSP. WARNING OCCURRED 28 SECONDS AFTER TAKE OFF, NO OTHER MSGS, NOSE GEAR RED, MANUAL RELEASE USED, HYD PUMPS AUTO, 160KTS, SMOOTH LANDING. REMOVED FLAGS FROM GEAR PINS AND INSTALLED GEAR PINS IAW AWAC SUP 11-054A REF 363804-4 FOR MEL. AIRCRAFT REMOVED FROM SERVICE. REF W/O 347128 W/C # 2,4,8 FOR REPLACEMENT OF HYD SYS #3 RESERVOIR AND NLG SELECTOR VALVE. SEE W/O FOR ALL RII'S FUNCTIONAL CHECK OF EXTENSION AND RETRACTION IS GOOD. REMOVED PLACARD AND REMOVED FROM MEL #3 HYDRAULIC RESERVOIR.