Hello

If this is the black plastic body antenna, then the very thin washers, maybe two go at the very bottom of the shaft and the other two thin ones at the top of the assembly, just below the circlip. The toothed track installation is made much easier, with the cover still removed. Below the motor is a drive gear. Remove it. Feed the toothed track down between the nylon pulley and the big center Wheel, about 2/3 to 3/4 of the way, then put the hollow cap over the top of the captured toothed track, put the drive gear back it, etc.