Method of assembly for gas turbine fan drive gear system

A method of mounting a gear train to a torque frame, the method comprising:

• providing a unitary carrier having a central axis that includes spaced apart side walls and circumferentially spaced connecting structure defining mounts that interconnect the side walls, spaced apart apertures provided between the mounts at an outer circumference of the carrier, gear pockets provided between the side walls and the mounts extending to the apertures, and a central opening in at least one of the side walls;
• inserting a plurality of intermediate gears in the carrier;
• inserting a sun gear in the carrier;
• placing a first ring gear part of a ring gear about the outer periphery of the intermediate gears;
• attaching a torque frame to the carrier, wherein the torque frame has a plurality of axially extending fingers which are received within slots in the carrier, at locations circumferentially intermediate locations of said intermediate gears, wherein the ring gear is formed as a two-part gear including the first ring gear part and a second ring gear part, and wherein the second ring pear part is mounted to the outer periphery subsequent to the step of attaching the torque frame to the carrier;
• and
• moving the first ring gear part such that the first ring gear part does not line up with radially inwardly extending apertures in a radially outer surface of the carrier, and then moving pins into the apertures to lock the fingers within the slots.