There  is  no  assembly  on  the  fan  unit  just  wing  nut  on  the  base  female  pipe  which  slides  over  the  stem,  do  not  over tighten,  there  is  only  2  -  3  turns  of  threads  and  they  can  be  stripped  out  if  manhandled,  but  worked  perfectly  for  me,  remember  it  only  needs  to  be  tight  enough  to  hold  it  in  place  from  spinning,  don't  treat  it  like  it  was  the  lug  nuts  on  your  car,  and  it  does  what  it  was  intended  to  do.