kskane

Hi Guys, I have searched in different places and cannot find the right tightening torque for the bolts holding the two mechanical tensioner pulleys on my M54 E60 engine. I can't find this detail in TIS or Bentley manual (unless it is supposed to be derived from generic bolt torque spec)
I have attached the pictures of the new pulleys I am trying to install, but before I go ahead, I need to confirm the tightening torques on the bolts that will be holding these two new babies. From the look, it is a silver bolt 8.8 (probably M10, not sure until I pull it out). So, many of you out there who have done these pulley replacement, I would appreciate if you can share your tightening torque for both the AC Tensioner and the Alternator/Engine belt tensioner (pictures attached)
Thanks in advance.

champaign777

All M54 pulleys have the same torque 45 Nm ( 33 ft.lb )
M54 alternator - pulley crazy torque 44 Ft Lb - Bimmerfest - BMW Forums

kskane

Thanks champaign777, I have read that thread before. Can you see the image below from TIS and tell me if that makes sense. I know you have been using 45Nm and it has not caused any problem, but is that what is recommended by BMW or in general based on bolt size or something else? Just want to clarify where the 45Nm value is coming from?

champaign777

these values come from Bentley Manual , torque specs for M10 bolts and common sense
GL

kskane

Thanks for confirming, and common sense now a days not really common, but I know what you mean.

Digged a little more into the BMW TIS and found these;

Alternator/Engine mechanical pulley - 45 Nm
AC Tension pulley - 35+/-5 Nm