This nut was not that tight on mine. As you know its reverse threaded so you are going in the correct direction by going right or clockwise to loosen it. But on mine the fan pulley would slip. there is that special bmw tool that has holes in it to hold two of the bolts on the pulley to keep from slipping or people here made theirs with a template and the clamp rod i mentioned. For me i used it on edge and used the thin part of this rod to go on one side of a bolt and the other side of the next bolt. This way you hold the fan pulley while you turn the nut. You have to have a thin cresent wrench that I believe goes up to 36 mm OR you need a long big wrench of this size . They have a set of these at Harbor freight and its not sold individually. However the wrench of the right size thats not a crescent is much longer and gives you leverage, like a breaker bar to loosen that nut if its too tight. IF it is too tight the pulley for sure will slip on the belt, even with mine which was not too tight it would slip and you have to hold that puley. Hope this helps. When you do put it back don't overtighten, remember its reverse threaded and cant come off anyway. Just tighten it a little the same way you took it off.