What was found
ON SOME MAIN ROTOR TRANSMISSION ASSEMBLIES, THE SPLINES ON THE PULLEY ASSEMBLY DRIVER BOTTOM OUT ON THE SPLINES OF THE GEARSHAFT INPUT BEVEL PINION (369A5107-21). THIS RESULTS IN A GAP BETWEEN THE GUARD (369H5657) AND THE SPACER (369A5165). OPERATING WITH THIS CONDITION WILL DAMAGE THE INPUT PINION AND THE PULLEY ASSEMBLY. SUBMITTER RECOMMENDATIONS, CHECK FOR THIS CONDITION WITH ANY REPLACEMENT TRANSMISSION ASSEMBLY, MAIN ROTOR.