So it was only the press fit (and, ha ha, the grub screw) that was carrying the driving torque for the top pulley? That doesn't sound like competent engineering, especially for Greenfield, the minimum acceptable would be a medium press fit, or freezing the inner sleeve to an extremely low temperature before assembly. If they had done either of those, you wouldn't have separated them without a decent press or an oxy torch. Were the two pulleys attached to each other, say by some serious industrial adhesive?
