In the process of replacing shocks & springs on my 2004 325xi touring and have snapped off the lower bolt that passes through the control arm/hub mounting bracket which pinches the bottom of the shock. Of course the bolt head and only a small amount of the threaded bolt shaft broke, so the majority of it is still in there which makes it impossible to remove the shock. Tried a bolt extractor, but that broke off too. These bolts are very rusty and penetrating fluid just does not seem to help at all. A this point I am stuck with the car up on jack stands. I don't know how to get the bolt out and trying to cut it out doesn't seem like it will work. Any advice here would be greatly appreciated.
You'll probably need some heat from a torch to expand the metal around the stuck bolt, as well as more penetrant (Kroil, PB Blaster). Are you able to get pliers/Vice-grips on the remaining stud to twist it? If not, you'll need some more high-quality extractors, or you might need to do more disassembly to get a better look at the bolt. Are there any local club members with good mechanical skills that you could call on for assistance?
The "Outside Machinists" (e.g., Assembly Mechanics) in our shipyard have just the tool you need. They have a bolt "disintegrator" that they use for exactly the same purpose, removing rusted and broken-of bolts. I believe it uses a very high powered ultrasonic pulse to shatter high hardness metallic bolts and pins. Unfortunately I have no idea who manufactures the device and I'm sure it costs in the $10,000 to $20,000 range. Sorry... it sounds like liberal applications of PB Blaster followed by a torch will be required. Be VERY careful not to set the car on fire in the process!!!!
No luck Have had no luck even after trying to cut the bolt in half between the lobes of the pinch section. It has become a large mess. Still have 2 halves of the bolt preventing the shock from being disconnected. Luckily, my son works at BMW Sterling and will get a socket to remove the hub and the whole assembly (king pin with shock still attached) and take it to their shop. In the meantime he will put a new king pin on order along with 2 new shock bolts (other side came off but the bolt is rusty and I don't trust it). This design is so very poor. It allows salty water to collect in that connection and lead to such messes. Good thing I still have my trusty 318ti to drive in the meantime! Thanks again for the advice.
Nice to have a tech in the family; double-special if Sterling allows him a parts discount! Their parts pricing is typically the highest in the area.
Took the ti on a 300+ mile roundtrip to PA form VA yesterday. That car is such a sweetheart! The only thing that must be changed soon are the front seats! At 170K miles, they are a little flat and the foam is gettin' crumbly. The xi will get the king pin removed tonight.
