Nissan Repair: nissan pintara 89 model, brake caliper, lug nuts

Question
when wheel is taken off  and brake unit, the disc falls  off the studds what is meant to hold the disc on is there anything meant to hold it in place as it only has brake unit and wheel holdening it in place and seems to vibrate badly

Answer
The disc is held on by the tire rim and lug nuts and when the the brake caliper is removed, the disc comes right out. As for the vibration, check tire for out of round, out of balance, make sure the rim isn't bent as a result of an accident or hitting something hard and make sure that the disc is not warped.