I may have found another error in REAL OEM, ITEM #3, is not a torx. However, just thought of this, click on the part number. It supercedes what is on there now. maybe this is what occured with your bolt.
E60, E61 Parts, Accessories and Mods - Installed M5 OEM reinforcement pull rod - Installed M5 OEM reinforcement pull rod ^_^ I found these two pull rods in M5 and M6 only. That's why try to install and found here add stability and stiffness to the chassis. Especially during cornering. 120542...
I just clicked in this thread and read it. I can confirm that on the 2 LCI’s that I recently have removed the bars, they were both external torx with captured washer and locitited. I seem to remember that also on the ‘10 I dismantled but that was over 2 years ago. I’m assuming on the other ‘08 I have that it’s the same. I also ordered the replacement fasters called out in ETK/realoem. Those are indeed a hex bolt. Most of the times in these situations it really doesn’t matter what the head is, it’s the length, dia, and area under the bolt head that matter. Service part numbers often have a different engineering release than what is at the factory. I could go on to describe some of the reasons for that but not sure if people really care about that.
well there are dozens but here are a few based on my time as a process engineer and as a D&R.
1) manage obsolescence and proliferation. It is very costly for BMW and the dealership base to have all every single part available as a spare part, when there are functional equivalents. Those 2 etorx bolts is the only one that I know of anywhere in the underbody chassis area. A hex head that is already released in the system does the same thing and is used in multiple cars. That is the job of the design and release engineer to manage the release of parts (final production only, supplier only, service only, all three, obsolete, supercession, etc.)
2)There is fixture tooling on the final assembly line that travels with the car and it requires a fastern that has better self centering than a conventional dog point bolt and will not fly off or fall off. Just by looking at the orignal bolt and this part, I presume that there is a fixture that holds the bars in place, and likely an automated nut driver that needs the bolt to find center before it drives it in and achieves final torque. These things often times have automatic bolt feeders on them and the tooling can jam or strip a normal hex bolt because etorx are the best at allowing for the fastener to be held and fully engaged in the socket. etorx rock for situations where the bolt has to be held in the tool horizontally. You can observe for yourself how helpful that is when installing the top 4 bolts on the bellhousing to engine.
3) the operator also also has other tasks within his station that require a E12 torx, not a standard 13mm hex bolt(or what ever the bolt head size is). This would be the case if these are not installed with a jig as mentioned above then it is done with a conventional DC nut runner. It is very seldom that any station only has 1 operation. The assembly line would need like 10x people and have to by 5x longer.
I doubt this 4 is the scenario vs 3 it since Germans LOVE automation, and pure manual labor is a thing of the past at German assembly plants, it's far too expensive. The operator still needs assistance to get it in the hole fast without cross threading, it's a blind hole. Already mentioned how etorx stay on the socket better. You don't pick up dropped bolts in production and reuse them unless maybe you are in a Tata Motors or Geeley plant. Also hand start bolts take up time and case repetitive stress injuries. Imagine hand starting bolts 500 times a day overhead. None of us would ever last.
Great explanation! As I learn more about BMW's, I'm amazed at how the cross-pollinate parts with other models. I'm sure that helps keep costs down as they are a mass manufactuer and allows them to create a M vehicle for much less than what it would cost a smaller company like Ferrari to produce the same/similar car. that probably gets them into some interesting design decisions and trade-offs.