Coil spring compressor
Newbie
Joined: Feb 2021
Posts: 12
Likes: 8
2012 ML350 BT
I just replaced both of mine. You don’t really need a compressor at all. If you support the lower ball joint and lower the car to take the lower shock bolt, one end of the sway bar link, the three bolts for the upper control arms, remove the brake caliper, the lower control arm will drop far enough that you can get the spring out with only a little persuasion of a pry bar. I put new springs and the lower spring perches in. Make sure the new spring is indexed correctly so that the ends of the springs fit up against the stops. The lower perches have a notch so it only fits in the hole in the lower control arm one way. I also had to pop the plastic wire holder for the ABS sensor out of the one upper control arm just to make sure none of the wires got stretched. The brake hose pops out of those clips easy and gives you just a bit more flex. I have a lift so that did make it a bit easier by putting a support under the lower ball joint and lowered the car slightly to pull all the bolts out, then lift the whole vehicle up or lower the control arm and almost all of the tension is off the springs. I was able to push the new springs into place with minimal effort. after the spring was in I just lowered the car down slowly on the support under the ball joint till the shock bolt could be installed. Then you can simply put all the bolts back in and tighten them down. None of the bolts the fasten the control arms to the knuckle adjust the rear alignment so they can be removed and reinstalled without affecting it. I also removed the bolt that holds the level sensor to the control arm on the passenger side just to make sure that it didn’t get damaged from over extension. An impact gun speeds the process up quite a bit.
