viscous fan replacement. help needed
 

i have removed the viscous fan as i needed to replace the oil filter housing gasket on my 2004 3ltr petrol x5
how tight do i do the fan up when replacing it please?

Just smack the wrench with a mallet and you should be good. Reverse threads so it can't come loose. That's all I have ever done...

From my weak memory, I believe the spec is 40 Nm, but you need to apply that using a special tool torque extension, applying 30 Nm on the torque wrench to get 40 Nm at the nut.

However, what I've found, having had the fan off and on a few times, is that I don't torque it at all. I don't even smack the wrench with a mallet any more.

I just tighten it with a wrench, resisted only by the friction of the water pump and belt. I also use antiseize on the threads. I do it this way since I also remove the fan by hitting the wrench with a mallet.

Due to the left handed threads, it is self-tightening, and I can't imagine it ever coming loose on my own. Being stuck on too tight and difficult to remove - yes, I have seen that happen. I bought the special tool to handle that after first buying the car, with the nut on tight. Have not needed that tool since switching to this method.