Stuck dogtooth nut for fan

[yavuzss]

I'm trying loosen the 42mm dogtooth bolt, supposed to be torqued to 130 lb/ft but it doesn't turn. Since it's bolted to crankshaft, is it safe to use impact wrench?

[Stonehopper]

You should not have any trouble using a rattle gun to loosen the bolt securing the fan onto the crankshaft. Anti-clockwise to loosen.
But avoid using an 'impact wrench' that uses a blow from a heavy hammer.

Once the nut is removed, you will find the fan is a taper fit on the crancshaft. It may come off easy, but probably won't. The trick is to use a bar that fits easily into the dog teeth as far as it will go, give it a wiggle sideways (it may loosen it), but if it shows no sign of moving (most likely), then strike the bar on the side (not the end). This might take several blows, but should break the fan loose for removal. It's the same practice as on the 2cv.

PS: You state 42mm nut. I'd forgotten it was that big!

[yavuzss]

Thank you for your advice and quick reply. I bought the car few months ago, looks like someone welded the bolt in the past, I hope it won't be a problem

[Stonehopper]

Good grief! It's been a while since I have worked on mine.
You will need to grind off that weld (maybe you have already). Then the dogs might need hammering inwards for the nut to clear them.

[0x00fj]

I took mine off with an impact gun this weekend. The nut took the threaded starter dog with it. I don't think that's how it's supposed to come apart, but it went back together just fine.