PeachParts Mercedes-Benz Forum - View Single Post - Possible to Remove W124 Lower Control Arm Without Spring Compressor?

gmercoleza · #19 01-26-2007, 11:32 PM

SUCCESS! Well I just removed the control arm successfully WITHOUT a spring compressor. It was so easy I'm actually quite amazed. I don't think doing so was dangerous at all. Here's what I did:

01. Set parking brake and chock rear wheels.
02. Jack car very high up at center of crossmember.
03. Place 2 jack stands at frame near jack points.
04. Remove wheel, caliper, and sway bar with impact wrench.
05. Separate steering knuckle from outer tie rod.
06. Remove jack, place under control arm, jack up slightly.
07. Remove ball joint pinch bolt with impact wrench.
08. SLOWLY lower control arm, then remove spring.
09. Remove eccentric control arm bolts, then remove control arm.

Note in step 8, as long as you lower very slowly, there really is no need for a spring compressor. I rented the loaners from AutoZone to be safe, however the jaws were too big to fit between the coils so it turned out I couldn't use them anyway. Just for safety I ran a ratty old 20 amp extension cord through the spring as indicated by the yellow line in my previous picture above, but it never came into play and I don't see how it would since the control arm's geometry will not allow it to let go of the spring until the spring is almost fully extended. Once the ball joint pinch bolt is undone, the control arm just needs to drop somewhere between 45 and 90 degrees and you are home free.

At the end of the control arm travel, it appeared the arm was "springing" back up, making separation of the ball joint and subsequent removal of the spring a little precarious. Upon observation, it appears this was a function of the rubber bushings acting counter to the eccentric bolts; in the future I believe loosening the bolts enough to clear the eccentric will reduce or eliminate this springy feeling, allowing the control arm to drop all the way to 90 degrees more easily.

It does look like reinstalling the spring is going to be a royal pain, only because it is going to want to pop back out. But I'm sure I can get it to catch just a quarter inch of the control arm indentation, which is all that is needed to be able to raise the arm and compress the spring once again.

In summary, it is my opinion that a spring compressor is more of a convenience for this job. I could see where it could be essential for other jobs, such as when you wish to remove the spring without disturbing the ball joint and/or tie rod, etc. but for my purposes it was perfectly safe to remove the spring without one.