I'm the type of person who researches any job extensively before giving it a go. I haven't found any true DIY for Sway Bar End Links and for good reason. It's a very easy job. But if you're looking, here it is.

Symptoms:

My car would clunk the most going below 20 MPH over basically any kind of road surface imperfections. I (a more perceptive driver I might add) could feel the clunk through the steering wheel and brake pedals and possibly through my seat as well. I could hear it enough for it to be almost unbearable, though my less attentive passengers could not. Regrettably I don't have any audio clips of the clunking to share.

I performed the "jerk the wheel to the left and right" test which did not cause my clunking. Therefore I thought it might have been a different control arm, but alas it was not. I believe Airmatic just does a good job controlling side to side sway to begin with.

I had two inspections done on my car (with the clunk noise audible) through an indie mechanic along with two MB dealers, and they all did not report any faults with the vehicle or any strange noises.

Tools:

You DO NOT need a scan tool to air down the Airmatic strut.

-- a means to lift your front wheels off the ground
-- 17mm socket
-- 18mm socket
-- 18mm spanner
-- hammer/mallet
-- torque wrench
-- impact


DIY:

1. Begin by lifting your car or jacking the front end.

2. Remove your front wheels using the 17mm socket and an impact.

3. Use your 18mm spanner to undo the lower nut (pictured) (lefty loosy righty righty). You will most likely need to use a hammer on the end of your spanner to work it loose. It appeared to be very tight but came loose within 10 medium blows of the hammer.



4. Use your impact and 18mm socket, and loosen the upper nut (lefty loosy righty tighty).


5. Remove the link. You may need to slightly contort each bushing but the link should NOT be under tension at all. Both of your front wheels are in the air so there should not be tension on the sway bar.

6. Feed the top bolt into the hole on the control arm

7. Thread in and tighten the bottom nut first, using the spanner. Tighten until it seats fully and does not go any further.

8. Thread on the NEW upper nut by hand, until it stops roughly midway on the shaft. Note: LEMFORDER gives two of these nuts in each package for some unexplainable reason. You only need one. These are special nuts with a built-in washer, that cut into the bolt to prevent accidental loosening. I do not advise reusing the old nut.

9. There is a guide pin on the head of the link that must fit into its corresponding divot on the control arm. Locking pliers would be nice to hold both sides together correctly but not necessary. I just used my hand and squeezed them both together while tightening.

10. Use your impact to further tighten the nut, but not too tight yet.

10.5. Ensure that the control arm sits tight (the guide pin...) and completely flush against the control arm. If not, the guide pin is not aligned with its hole.

11. Torque the top nut to 80NM (60 lb-ft). You do not need to counter hold anything as the guide pin does so for you. You do NOT need to preload the suspension before torquing.

12. Once everything is nice and seated, use the spanner and hammer the bottom nut tight to "that's not going anywhere" spec.

13. You should ideally replace these in pairs. Both sides are 100% identical.

14. Put your front wheels back on with your lug bolts as tight as you can get them.

15. Lower your car back to the ground

16. Torque your lug bolts to 150NM (110 lb-ft) in a star pattern

17. Test drive!

18. Recheck and ensure that your lug bolts are torqued to spec. and did not come loose. Sometimes the wheel isn't seated right and double-checking is always good practice.

Done!

That's it! Very happy that this simple fix solved my clunking. The upper bushing on my right side (as I predicted) was bad and is floppy and not as tight as the rest.

This is one of the easiest and most straightforward repairs you can do, and it's even easier for 4matic vehicles as you don't need access behind the strut. If your car is clunking, don't be scared and go do this repair yourself!

 

Great write-up and thanks for sharing. Also what is the age of your car and the KM/Miles?

 

My car is a 2017 (going on 7 years now... wow) with just shy of 80,000 miles. However, I do not know when the clunking developed initially.

I bought the car with 76,200 miles (from an MB dealership...) and I noticed the noise on the drive home. I had a PPI done by a German mechanic who also did not notice the noise. And my local MB dealership also did not notice it.