Removing m20 viscous fan?

[bmw9818]

I know it's reverse thread, looking at car head on turning it to the right, 32mil bolt, I'm trying to undo it, wd40d it, I got the spanner on and just hitting it with a hammer? Ain't budging though,

[TouringTash]

How big a spanner and how big a hammer?
Go and give it another drowning in penetrating fluid, have a cuppa, then have another go.

[Barx325i]

also try tightening the belt a bit a little with a zip tie, and possiby heating the 32mm nut a little with a jet lighter etc.. it won't take much heating before it expands a touch

[Brianmoooore]

How easy it undoes depends on whether the last person that fitted it just nipped it up or decided it needed loctiting and torquing to 200Nm.
If all else fails, find a piece of flat steel bar, about 25mm x 3mm x 250mm, and drill a 6.5 mm hole close to one corner. Remove one of the fan pulley bolts, and bolt the steel bar in place using a longer bolt. Use the one that came out, and it WILL strip the thread.
When you turn the coupling with the 32mm spanner, the steel bar will lock against the centre hub of the pump and hold the pulley and pump still.

[Alburglar]

I have a 'special' old thin chisel that fits in between the pulley bolts to lock it off, but as the others suggest, a good thwack after loads of wd40 usually does the trick.

[bmw9818]

Sorted I just used a pair of pinchy mole grips on the water pump pulley so it locked against the block, got the spanner on it and used a jack handle for leverage! Came undone with a big ass squeak!!

The hammer was just damaging the nut, seemed po did loctite it quite a bit!

[Barx325i]

good work, copper grease that squeak!