What was found
NOSE WHEEL DID NOT RETRACT AFTER TAKEOFF WHEN GEAR WAS SELECTED UP GEAR DISAGREE AND NOSEWHEEL DOOR OPEN WARNINGS ANNUNCIATED. GEAR DID NOT RETRACT. RAN EMERGENCY CK LIST, EXTENDED GEAR MANUALLY. DECLARED EMERGENCY BACK INTO MSP LANDED BELOW 47,000 DESCENT RATE BELOW 600 FT PER MIN. AIRSPEED REMAINED AT 200 IAS NO OVERWEIGHT LANDING. COMPLETED MM409 NR 352863. REPLACED NLG OLEA CENTER/EXTENDED PROX SENSOR BRACKET PN 16215-105 AND ADJUSTED SENSOR GAP. OPS CHECK GOOD.