Headlamp bulb burning out too frequently

[IceBlue]

Greetings fellow Saabsters,
I have a 2007 9-5 Aero that has done a yeoman's service for 12.5 years now. My driver's side headlamp is burning out much more frequently than what I would consider normal. It was last changed in early August and it just burned out yet again. A 3-month life span strikes me as much too short. This abnormal frequency has led me to believe that something else is amiss. Has anyone else have this issue and hit on a cause?

[phoenix]

 This is often caused by a loose spring mounting causing excess vibration of the filament. Perhaps the spring needs bending back into shape to ensure it holds the bulb firmly in place.

[sgould]

Agreed. Vibration can also be caused by loose headlamp mounting bolts.  I had this problem a long while ago before I got into Saabs and it was caused by a very rusty mounting that allowed the whole headlight to move about.

Are the two manual adjuster screws OK?  If they have been broken, the headlight won’t be held firmly.