Just got finished replacing my fan clutch and plastic fan blades. Have 87k miles on my 2001 540i 6sp and had heard horror stories of fan blades braking loose & causing great distruction. So this was for prev maint. Mechanically a very easy and quick process. Great DIY on this here at BMWCCA. Car even sounds better with fan and clutch.....go figure technical info on the blade replacement. Installing the new fan blades on to the new clutch, I used the old torx head bolts. Applied blue thread locker and torque value is 18 nm (around 13 ft/lbs). A little copper slip (anti-seize) applied to clutch nut to allow easier removal next time. hope this helps.