In Reply to: lower control arms posted by Dick Nyberg on April 02, 2000 at 01:02:52:
As far as I know, 525 and 535s came with aluminum arms. 530 and 540s use steel arms. The arms look a bit different, but are dimensionally the same. The steel ones are a bit heavier. Perhaps one or two pounds, tops. Neither has a replacable ball joint. I replaced the arms on my 525i with the steel units. The $414.00 price difference is nothing to sneeze at. The increase in unsprung weight was never an issue for me. After all, going to a +1 or +2 wheel swap will pick up lots more unsprung weight than the arms ever could.
Go with the steel arms. You'll never notice the difference between the two in ride, and your wallet will thank you.
: I went under the car today('92 535) looking for cause of the old 55mph braking wooble and found loosness in the ball joint of one lower control arm. I realized that they were aluminum - surprised me for sure. The BMP cataloge lists aluminum and steel lower control arms at $63 and $320 each respectively. Leads me to the following questions:
: Did E34's commonly come with aluminum lower control arms? Has anyone experience with 'downgrading' from aluminum to steel? (Yes, I may cheap out on this one.)
: Lastly, I believe you can't replace the ball joint in these units. Can someone please tell I'm wrong?
: I hear the cool trick on popping out the ball joint on these is to partially engage the nut on the top of the ball stud and then put the suspension plate back on the bottom of the strut. Then slowly tighted the three plate bolts to push the ball stud/nut aginst the bottom of the strut tower. Slick.