TC2000 says the threads are partially striped.
You are going to have to use heat, serious heat. You'll need an oxy-acetylene torch so you can heat up the whole length of the tube. A very dull red should do it. A propane torch doesn't put out enough for this kind of work. Let it cool SLOWLY so it doesn't harden.
Thanks all for your help.
This all started because the right tyre is very very close to the body (even touching when turning), meaning the distance between front and rear wheel is shorter than on the other side.
I have 2 reasons to remove that pin:
1/ the thread is striped and I am not confident that I can tighten the wishbone properly,
2/ the trailing lower wishbone is trapped because the space between the body and the end of the pin is too small.
for 1, my solution is to thread the pin with a M12x1.25 dye. Pitch is very close to the 1/2 UNF (1.27). By doing that, I can use a M12x1.25 nut (standard wheel nut) to secure the wishbone. see pictures.
for 2, I am considering to remove about 4 to 5 mm from the pin; should be enough to free the wishbone. It seems the nyloc on this side is thinner than anywhere else (15mm instead of 18mm), maybe on purpose.
Doing that, I could leave the pin in place.
Now, the findings: the leading lower wishbone is bent and the weld around the tube where the damper is bolted is cracked all around, I will change all 4 to tubular ones. The previous guy who fiddled on this car (not a mechanic
)mixed the upper trailing arms and put them on the wrong sides (although they are clearly marked LH and RH); he had problems aligning everything so he trimmed the holes - they are elongated :'( .I will weld washers at the correct place.
All nyloc nuts are pretty loose, need to change all of them.
