The present invention relates to a method of assembling a drug delivery device which in the assembled state defines a distal housing component (102) that houses a piston equipped cartridge (189), and a proximal housing component (101) that houses a dose setting and expelling mechanism. The method includes the steps of arranging the cartridge (189) in the distal housing component (102), arranging a nut element (140) threadedly engaged with a piston rod (107) in the distal housing component (102), and securing the nut element (140) relative to the distal housing component (102) into a selective one of a series of predetermined relative orientations for obtaining a predetermined axial clearance or abutment between the piston rod (107) and the piston of the cartridge (189). The invention further relates to a drug delivery device assembled according to the method.
