What was found
CLIMBING THROUGH FL350, NR 1 EGT GAUGE INTERMITTENTLY AND RAPIDLY OSCILLATED SEVERAL TIMES PLUS/MINUS 400 DEG FROM APPROXIMATELY 760DEG AVERAGE. THIS RESULTED IN A PRECAUTIONARY SHUTDOWN OF THE NR 1 ENGINE. AFTER SHUTDOWN, INTERMITTENTLY WENT FULL SCALE DEFLECTION BOTH HIGH AND LOW, 2 TIMES, THEN RETURNED TO 0 DEG. NO OTHER ABNORMALITIES NOTED. REMOVED AND REPLACED RT EGT MANIFOLD IAW DC8 MM CH 77-20, OPS CHECKS GOOD.