What was found
SHORTLY AFTER LIFT OFF AT 35,000 FT, THE NR 2 AUTOPILOT DISENGAGED, FOLLOWED BY THE NR 2 SOURCE OFF LIGHT ILLUMINATION, FOLLOWED BY NR 2 DRIVE LIGHT ILLUMINATION. EMERGENCY DECLARED DUE TO AN ACRID ODOR IN COCKPIT AND CABIN. LANDED APPROXITMATELY 20 MINUTES AFTER INDICATIONS. NR 1 AUTOPILOT WORKED. ALL QRH CHECKLISTS ACCOMPLISHED. AIRCRAFT WAS GROUNDED. ACCOMPLISHED MCM 05-96-70 SMOKE ODOR FUMES CARD FOUND THE NR 2 GCU BAD, ACCOMPLISHED HUD TEST, PASSED AND PERFORMED A LAND VERIFY TEST, PASSED IAW MM 22-11-00. LEFT FORMER NR 1 GCU IN THE NR 2 POSITION MM 24-21-81.