Assuming you're doing everything right, here's a tip that might help enough to get it loose:

The spec is to use a 32mm open end wrench. A 1-1/4" wrench is just a little tighter = 31.75mm. That slight difference with a good quality wrench may make the contact firm enough that it pops loose when you whack it.

EDIT - is this the fan nut you're talking about? Reading again, I see you say fan clutch bolt. It's always the fan nut that is tricky.

__________________
2001 X5 3.0i, 203k miles, AT, owned since 2014