Call Me Dane l 2/2004 330i ZHP l 18x8 ET45 BBS CK's wrapped with Michelin Pilot Sport AS3+ @ 245-40-18 l KW V1 Coilovers in front l KW V1 springs w/ Bilstein B8 dampeners in rear l BMW Performance Rotors l UUC StrutBarbarian l Racing Dynamics Rear Strut Bar l Jim Conforti Shark Injector l Light Birch Interior Trim l Bimmian Celly Mount l M3 Trunk Mat l l e90 Performance E-Brake & Shift Knob l M3 Tri-Stitched Boots l AL Headlight Retrofit with ZKW Lenses l CobyWheel Wrap w/M3 Stitching l LCM sw 4.5 triple blink and rear fogs l Maple Interior Trim
Now that I think about it some more I would try removing the other two bolts and use a piece of wood to pry up the aluminum end of the strut brace. It shouldn't take much to get the splines to bite and then tightening the bolt would pull it back up into place.
William.
2006 CiC 6MT
ZHP, Cold Weather, Xenon
Sapphire Black / Black Leather / Black Cube
I had this happen to me when I first tried to change strut mounts. A stud fell out. Best case you just push it back up so the splines bite, as said above. Middle case the stud falls down into the wheel well when you remove the nut. Worst case is replacement stud won't stay in and you need a new strut mount, which is not expensive, but changing the strut mount means pulling the strut out and using a spring compressor.
One trick to try if you still want to remove the nut is use a pair of needle nose pliers to lift up the nut while you unscrew it with the 13mm socket. That might let the splines bite enough to finish removing the nut. But then after that there's still the risk the stud will fall out if you tap it by accident. This is kind of like what WSmeyer suggested.
Strut mount was busted. Ordered a new one. Hope to be up and running by this weekend.