This is the typical 911 Sway Bar failure.  The brackets on all cars through 1989 were just sheet metal.

As a result, even with thin 19 mm bars like those shown here, the bracket rips off the chassis.
 

Not the wntire bar is offset about 3/4" backwards.

Sway bars are not supposed to sway in the wind!

Nice

Luckily the pieces were in decent shape.  You can buy an updated bracket form the factory with the "Butterfly" reinforcement, but then you have to grind off the old one, spend $80 on a new one, and still weld it up, so we generally fabricate a reinforcement.

The passenger's side was OK., so we just reinforced it.

Here it is repaired and welded.  We used some 1/8" flat steel stock to reinforce it and it makes a very
strong repair.

Here's the view from outside the car looking toward the centre.

Here's the reinforcement on the passenger side bracket, which was unbroken.
All set and ready yo bolt the sway bar back on.  This guy was too "frugal" to go for a decent bar so the stock unit was reinstalled.

We charged 3 hours and $15 in materials to do this, about $190.  If we had purchaced the factory reinfoced brakets, it woudl have been
about the same amount of labor and supplies, plus $175 in parts.