After several phone calls and a few visits to local panel beaters,
I found that the cost to repair this was somewhere between A$150.00 to A$450.00.

After searching the web for a few minutes, I found an excellent post by [email protected] on the excellent site http://au.geocities.com/ozbrick850/index.html.

His bloody marvellous instructions are in red
 

“It seems this is a common occurrence on many 850s. Mine had the bad version of it - the weld in the pillar gave up and the plates squeaked and growled with every opening of the door. After checking for possible approaches to fix it, it became clear why there is so much work involved when welding is chosen. They have to take apart the interior trim, knee bolster, electric wiring, and access the inner side of the pillar, then remove the door, which is a colossal amount of work. A pleasure for mechanics, who cash grossly for these trinkets. I came up with a simple solution which is now 3 months old and  holds as good as a weld. I did it alone and doesn't require any interior work.”
 

I thought to myself OK seems easy enough, I’ll give it a go using these instructions...
 

“Who wants to give it a try, follow this:

You have to take down the door, which is simple - 2 jackstands under the door in the open position (tape generously the upper face of the stands to avoid scratching the door and then push the stands up as far as you can, even forcing the door a little up -it will help to remove the hinges).”
 

I a bit lazier than this, so I didn’t use any stands, the hinges are attached by pins which won’t allow the door to fall off, but the stands may be useful for others because the door is heavy and care should be taken when lifting it off, NOTE:- Now is the time to lower the window, because your just about to disconnect the electrics.
 

“Unplug the door electric connector by removing the small lockscrew and then twist the plug -which will come out (I didn't disconnect the battery, the contact was off anyway) Remove the big torx bolt on the strap and the 2 bolts that lock the hinges.”
 

This was very easy, the Torx bolt on the door strap needs a special driver to undo it, but you can use a 10mm socket to loosen the door hinge locking bolts they don’t have to be totally removed, just loosened a few turns.
 

“ then slowly raise the door (window down)  and slide the hinges up to clear their brackets. When removed, put the door with the inner face down in a clean place.”
 

Make the place where you put the door quite close to where your working, its really quite a heavy door.
 
 
 
 
 
 
 

Heres where you get to see the problem, the two spot welds have fatigued and cracked.

This is a design fault, so check your car if the dealer warranty is just about to expire.
 

“Now find the big hole just in front of the strap on the pillar, covered with a big rubber plug. Remove it.
 

The big rubber bung hole is visible to the right in this picture, with the electrical connector above.

Now’s a good time to wipe off the old grease from the hinges, and go get a magnet, I use the magnets from busted Hard disk drives, they are really, really powerful rare earth magnets, and are well worth the effort of dismantling a HDD.
 
 
 
 
 
 
 
 
 
 
 
 
 
 

“Drill 1 (or 2) 6 mm holes close around the strap- where the separation of the inner plate is most visible - depending on the severity of the separation you will find if 1 or 2 holes will fit your case. You have to insert in each hole a good 6 mm bolt and nut, the nut in interior. Be careful to drill close enough to the strap and catch the 2 plates (they cause the squeak/growl), not just the pillar sheet metal.”
 

Note the use of the magnet to catch all the swarf when drilling the holes, you want to catch all this stuff as it will cause rust if it gets into the wrong places,
 

First I recommend feeling around at the back of the plate to get an idea where the back plate ends, the backing plate it has a tiny lip on the top and bottom that might interfere with your hole placement.

Secondly see if there’s anything behind where you intend to drill, just go easy when drilling holes in case of wiring etc
 

Lastly I got some paint and a cotton bud and painted the holes I had just drilled to stop any rust.
 

The big hole you removed the rubber plug from  allows you to access the interior of the pillar with your fingers and fit  a nut on the back of each hole, while from the outside fitting the bolt in the hole and catching the nut.
 
 

It takes a while to fit them-I taped with scotch tape the nut on my middle finger to prevent it from dropping indside the pillar -crucial idea after I lost 2 nuts inside ! When you catch the nut with the bolt, you're set.
 
 

This was a brilliant idea and worked like a charm but , I unfortunately wasn’t set as the nut just spun around, I couldn’t hold it with my finger - Bugger!!. So I went and found an old 10mm spanner, and using a vice I bent it 15 degrees about 25mm from the top, this allowed it to fit into the bung hole and hold the nut, I also tied a string to the spanner to stop it falling into the hole.
 

“Tighten well to strongly catch both plates, follow then with the second hole -one could be enough in many cases. I chose to drill 6 mm holes and fit 10mm bolts and nuts. I sprayed the fix with paint to prevent my bolts from rusting”.
 

I used some spare  Volvo M6 bolts about 10mm long with Locktite blue to stop anything shaking loose.
 
 

Reinstall the door, no adjustments necessary because you just unlocked the hinges and now you'll put the bolts back for each hinge, as it was before.

Don’t forget to put some Locktite blue or red to stop the hinge locking bolts and check strap boltfrom working loose, and regrease the hinges,
 

The last comes the bolt for the strap (don't forget the rubber cover).All operations on the door must be done with it opened as far as it will go. The fix is as good as a weld and costs 2 bucks, -excluding your work, which is, I recognize -pretty hard when you have to fit the nuts inside the pillar, blindly. But hey, what a satisfaction when you succeed!”
 

Thanks to [email protected]
 

What can I say…Heres a picture of the finished fix - Thanks for these instructions, its saved me a bundle and I do indeed find great satisfaction in spending only $7.95 on Locktite threadlock glue, and I recommend anyone with this problem to give it a go.
 

See box below for more important comments on this fix from owners...

 

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