Last year I replaced the original rear strut assemblies in my 2004 R53 with almost 160K. I reused the bolts that secure the rear strut mount to the strut tower. Recently I read that the "self-locking bolts" should be replaced. Why do they call them 'self-locking' and why should they be replaced with new?

 

"Self-locking" is a bit of a misnomer. That indicates an inner thread coating on the nut that prevents it from spontaneously reversing once installed. I doubt you'll have a problem even though you reused the existing nuts (coating will deteriorate over time). Replace them if it bothers you since they're easily accessed.

 

I am confused. I am fairly certain that what holds the mount to the strut tower is a bolt that engages a captive nut.

 

BMW MINI has certain bolts with encapsulated blue "loctite" type of thread locker which activates on use. Instead of spending $35 on the bolts that secure the seats to my car, I just put some loctite on each bolt before re installation. They sure do look for ways to separate owners from our money.

 

If it is the ones I am thinking about those particular ones are triangle shaped, and cut and form new threads as they are screwed in. Not sure why they want you to replace them. Maybe they wear as they form and don't bite in as hard if reused.

If you are going to be changing things regularly, go buy some normal M14 bolts and Loctite them in. Then you don't have to worry about messing up the thread in the arm.

James

 

You must be referring to the later R52 or R56 with the aluminum trailing arms. Most gen 1 has steel arms and no self cutting bolt threads.

 

My 2004 R53 had steel arms and lobed bolts.

James