My CPO warranty doesn't cover (no surprise) the creaking/thump that is likely caused by a slightly loose cross strut brace on my '07 550. So, it's DIY for sure on such a thing.

Are there any helpful hints before I get into it...appears to be a 30 minute job but thought I'd ask the experts (you).

Also - Are there any great after market strut braces that I should consider to augment the stock setup (front and/or rear)? Last I messed with this sort of thing was on my two e28's years ago.

I searched the forum, just didn't find exactly what I was looking for.

Thanks!

are you referring to the front control arms? there is a thread in the diy section. suspension must in normal position before tightening the bolts on the bushings. best way is to set car on ramps after replacing the arms.

I am referring to the brace(s) that runs from the center of the firewall back to the strut towers. Like a "v"...I haven't taken the trim or carbon filter out of the way yet to tell, but it may even be two pieces, dunno till I can see it. My understanding is that they can loosen and just need to be torqued down to resolve the issue.

oh, i dont think you have to do anything special there. just tighten them up. what happened to your old brace?

the torque on the bolts is ~25lb/ft if memory serves me right. you might want to replace the bolts, they've probably been chewed up by previous work to the car. BTDT. IMO, no need for an aftermarket one, the only difference would be looks. functionally it has to be the same thing.

Thanks! I guess if I was tracking this thing, I'd consider more bracing (e.g. horizontal across from tower to tower and rear towers, but I am not (yet). ;^)

Yeah - I found the SIB from 2007/08...I think it was like 27 Nm torque (~ 19 Foot Pounds).

Thanks again for the response.

There is a technical bulletin about this problem. ( SI B51 13 04 ). 4 strut bolts on the center support bracket can loosen and wear the mounting holes unevenly. Center Support Bracket needs to replaces with all new bolts.