90 525i brake ?

[cavemanhands]

I am helping a friend replace lower ball joints (control arm) and rotors. I am wondering what size that rotor nut is? It is relatively large compared to all the ones I have ever done (Not BMW) the largest socket I have is a 36mm and that isn't close. SO if someone could tell me the correct size so I can add it to my ever growing tool selection I would greatly appreciate it! Thanks!

(in SAE it appears to be at least a 2-1/2" - 2-3/4" nut.)

 

[Big Daddy]

A BMW rotor is held on with a small hex head nut. Are you referring to the hub nut? You do not need to remove the hub to remove the rotor.

 

[cavemanhands]

well, if I were to refer to GM type cars I would say it is a hub nut. Are you saying that it is simply an open hub design and is held on by the wheel studs?

 

[Big Daddy]

I would call number #3 a hub nut and you do NOT have to remove it to remove the rotor.

Number #3 in this photo is what you need to remove to get the rotor off.

 

[cavemanhands]

thanks Big Daddy, thats what I wanted to know!