Hellwig Sway Bar Clunk/Noise Problem Identified And Fixed FINALLY!
After throughly delving into my Hellwig sway bar clunk/bang noise problem I have finally figured out what the problem is and how to fix it.
Its not a side to side movement of the bar that causes the noise, it has to do with the ends of the bar itself.
It turns out the OEM Mercedes sway bar bushings that connect to the downlinks from the frame are sized to use a 1/2" bolt (or metric equivalent). The downlink holes in forked area are also matched to this 1/2" size.
The Hellwig bar ends are larger at 9/16" and this difference in size causes the snap, pop or clunk.
If you use the OEM 1/2" Mercedes bolts and torque them to 40 ft. pounds of torque as per Hellwig instructions, as you drive on uneven ground the bar ends are forced up and down and this movement of the smaller bolt (1/2") inside the larger diameter Hellwig sway bar bushings (9/16") cause the noise especially... under the tight clamping torque.
I drilled out the down link bolt holes to 9/16" slipped new 9/16" bolts through the downlink holes and Hellwig sway bar ends and viola! no more noise.
I also filled the gaps between of the sway bar ends and the downlink forks with washers. I then used nylock nuts on the bolt ends and only tighten them so they were sung only. No torque.
Not pinching the forks tight against the bushings allows for a smooth movement of the entire unit. Not using washers and pinching the forks sides against the sway bar ends and then torquing the nuts to 40 ft pds. just exacerbates the noise problem IMO. When the bolt does move up and down its does it with a snap thus the noise.
Hellwig needs to either change the inside diameter of the sway bar bushings to match the OEM Mercedes downlink bolt diameter or describe drilling out the downlinks and then provide the correct size bolts within the kit.
In the mean time heres the remedy to alleviating your sway bar noise.
Hope this helps.....it certainly cured my noise problem.
Tim + Denise Taylor
Denali Park Alaska
2013 Solera 24R