Azodin blitz regulator problem?

i just got an azodin blitz paintball gun,i took apart the regulator one day because the swivel on my gun got locked. so i take the set screw out and the reg has two parts, the middle big part and the bottom that unscrews. the middle big part wont screw off the gun, and also when i re-emble the gun i hear a rattling noise and i feel it coming from the reg. any help? in the reg there is a spring and a rod in the middle of the spring. also i have no idea of the factory settings, i took the velocity thing out of the back to clean it, and loosened the screw at the bottom til it came out when i dis-embled my reg. any help? the rattling was there when i first got it but it is worse now and it seems to be rattling even more. when i get the gun it rattled but it wasnt a lot but now it is a lot of rattling.