Replacing the Springs or Coil Springs on a SLK R170
This is just my experience and my way of doing it, not responsible for anything that happens if you do it like this.
After a wild search and not too much info, I have to get out there a few steps that I used to get this done.
Sorry no pics, just hard and time consuming taking pics while being dirty and crawling around the car.
Applies to installing lowering springs on a SLK R170, not sure if it applies to all years, but my car is a 2002 SLK320.
1. Replacing the coil Springs per Pelican is about 2.5 hours per each side, that if you have the correct tools.
2. Having the correct coil Spring compressor tool makes this task a lot easier.
3. Some elbow grease and nice words to go with it is recommended
Since I have never worked on the suspension fro a Mercedes before, coming from BMW's, this was a learning curve.
Here are the steps:
For the Rear, same applies for both sides, don't need to use the spring compressor tool on this one.
1. Jack the car up, use jack stands for safety.
2. Take wheels off, I started with rear and did one at a time
3. Remove the plastic protecting the control arm from the bottom, 2 7mm screws attach to the control arm, once removed the plastic just unclips from the control arm.
4. For rear the easiest way I found to work, use a jack to hold the lower control arm from moving while taking the bolts off, I pushed the bolts oput with a screw driver and a little push:
- Remove the 16mm bolt and nut for the shocks that is attached to the rear Lower Control Arm, spring sits on this at the bottom
- Remove the 13mm bolt and nut for the sway bar link
- Remove the 22mm nut and bolt that hold the hub attached to the control arm
5. Now the control arm should be able to swing down easily after removing the jack
6. Remove the coil Spring and pad, reinstall new lowering Spring, don't forget to put the pad back in and align the Spring with the correct end in the grooves.
7. Using the jack lift up the control arm to where it aligns with the Shock bolt hole 1st, reinstall nut and bolt, then Sway Bar Link and last the Hub
8. Tighten everything up, double check it's all tight and secure
9. Reisntall protective plastic under the control arm and secure with the 2 screws
10. Reinstall wheel
11. Tighten lug nuts
12. Remove jack stand(s)
13. Lower car and remove jack
14. ALL DONE with the rear
For the front a little more complicated, applies to both sides:
Mercedes Coil Spring compressor tool recommended here, I got one off Amazon for about $90, but found out it did not compress enough and had to use a pry bar to make things happen.
1. Jack the car up and install jack stands for safety
2. Remove wheel
3. Install the spring compressing pads into the coil spring, put them as far apart as you can, might have to insert at a lower or higher point then rotate until you get it to the outer edge as far as you can. top was about a rotation and a half, and the bottom was a rotation
4. Insert the compressing rod
5. Compress the coil spring as much as it goes, the coils in the middle will be almost or all touching after fully compressed (my tool did not compress all the way, it reached its limit about half an inch too soon, would have been way easier if it was all the way.
6. Once fully compressed the coil spring will become lose and you can wiggle it out of the control arm and spring perch ( I had to use a pry bar to pull it out)
7. Once removed from the car, decompress the tool and use the tool to compress the the new lowering springs same way as you compressed the springs when on the car.
8. Attach the top spring pad
9. Reinstall the new spring into the spring location, this is where I had to use a pry bar from the bottom to wiggle the new spring back in place.
10. Align the spring ends with the grove in the bottom of the control arm where it sits, and make sure the top spring rubber pad is aligned with the end of the spring
11. Decompress the compressing tool
12. Remove the compressing rod and pads
13. Make sure eveything is aligned and looks right, spring should sit in the groves on the control arm and top should be wedged in the top spring hole.
14. Reinstall the wheel
15. Remove jack stand(s)
16. Lower car and remove jack
17. ALL DONE with the front
I used the H&R lowering springs, I believe called Sport Kit.
Ride is stiffer and handles corners better.
This is my $1000 project, so I'm not worried about installing new shocks now.
Here is pics of before and after the lowering springs were.