I want to replace the rear shock absorbers and springs on my 1972 914-4 1.7. I can't get the large bolts out that connect the shock absorbers to the trailing arms. I've tried pretty much all the popular penetrating fluids plus heat. In addition, I have removed the calipers, rotors, and splash shields so that I could apply impact to the end of the bolts (on a sacrified nut). There are two flat surfaces on the inner ends of the bolts but they don't really hold an open end wrench well enough to be useful. No one seems to mention any problems getting these bolts out. What else can I try?

The right size wrench or a crescent wrench will fit the flats. I use a set of channel locks to twist and pull. Also have to keep shock vertical as the bushings will "lock" the bolt when trying to remove them.

Grease or put anti-seize on the bolt shanks before you put them back in.

I had one that was seized on the arm.

My only solution was to remove the arm, cut off the flat end of the bolt to remove the shock, then (with heat and penetrating fluid) I pounded the fuch out of the bolt until it moved, then removed the bolt and replace with another.

I was afraid that that's the case. It seems that there's no easy trick to getting these frozen bolts out.

This is what I did on a donor set I was given, attached to a teener!

Remove the trailing arms, shock towers and hubs (probably with half-axles attached). Be prepared to take your own impact sockets with you for the 2 different sizes.

Take the whole kit'n'kaboodle to the closest shop with a higher pressure impact wrench than the one you have.

Use heat and penetrating oil 1st, so's not to piss off the folks who will remove the nuts.

Have them do the outside hub nut and the shock mount nuts at the same time.

Oh, the total weight on a rusty set up, all combined can cause a hernia.

I am proof...

I can see that's where I'm headed too. It looks like I've exhausted all the possibilities of penetrating fluid (Ive tried just about all of them like PB Blaster for example), heat, impact, etc. Thanks for your comments. At least now I realize that this is a tough problem and I'm not the only one experiencing it.

Look at it optimistically.

On a scale of 1-10, this is a 4 or 5 once you've removed the back left and right assemblies (remember - HEAVY). CVs will be the toughest part as they are removed at the tranny housings and make the weight very lopsided.

Hell Hole repair or Tunnel Tube repairs for the accelerator or clutch are easily 7-8 in difficulty.

Work through it, don't hurry, and let the pros with the most air pressure do the hard part so you can continue on.

Good luck.