Inner hex bolt — a genuine BMW part, number 34 43 6 783 644. The number stamped on the part is 34436783644; BMW's catalog files it under the short number 6783644. You will find it on our Brakes shelf, under Other Brakes parts. It supersedes the older number 6778501, so a part carrying that number is the same part.
It fits every E46 body style (320i, 323i, 325i and 328i, 1999–2006), with the M52, M54 or M56 engines — and the European-market versions.
BMW draws it on 3 diagrams, among them Control unit box (12_0899) and Control unit box (12_1140). BMW's catalog calls for four of these at each place it is fitted. It weighs about 10 g (under 0.1 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.
