What was found
ON DEPARTURE WHEN LANDING GEAR SELECTED UP THE NOSEWHEEL ONCE RETRACTED KEPT MAKING A NOISE SIMILAR TO A PISTON RAPIDLY FIRING FOR 45 SECONDS APPROX- FOLLOWED BY A WARNING CAUTION LIGHT WITH NO EICAS ALERT - NO TRANSITORY LIGHTS NOTED DURING GEAR RETRACTION. TRANSFERRED TO NRWC 670-ORD-06133. DECLARED EMERGENCY-C/A-RAR NLG UPLOCK BOX IAW EMB 145 AMM 32-33-07 OPS CHECK FUNCTIONAL LEAK CHECK GOOD SEE NRWC 670-ORD-06133 FOR ADDITIONAL WORK PERFORMED