Hellwig Sway Bar Clunk/Noise Problem Identified And Fixed FINALLY!

[Toolman Taylor]

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.

The Problem:
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.

The Fix:
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.

[Still Kickin]

Toolman you should forward your findings to customerservice@hellwigproducts.com

[barnbnb]

Originally Posted by Toolman Taylor

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.

The Problem:
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.

The Fix:
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.

I installed the 7254 a couple months ago. Downlink bolts were supplied with it. I did not use the OEM bolts. The OEM bolts are sitting over in the corner of my shop with the OEM sway bar.
Maybe this has already been addressed by Hellwig. I have had no popping noise after installation.

[halbright]

My 2016 Solera came from the factory with the Hellwig sway bar installed. I have not noticed any popping noise.

[DBTSolera24R]

Mine came with the bar also and was clunking. The reason was FR put the one bolt it the axle crooked and cross threaded and it was tight to the axle. The bracket was still about an 1/8" away. Can't see how this was over looked installing. Had to remove and tap and reinstall with new bolts supplied by Hellwig.

[hkreck]

X2 with barnbnb.

[Cfritts]

I love how Joshua never comes on these and says "we are aware of that problem and working to eliminate it in production".

And now I know what else to look forward to being wrong on my Forester. Great.

[Pixelbum1]

NOW I know why I have a ROADMASTER anti-sway bar on my Solera!!

None of THAT nonsense at all...

[bclemens]

Originally Posted by Cfritts

I love how Joshua never comes on these and says "we are aware of that problem and working to eliminate it in production".

And now I know what else to look forward to being wrong on my Forester. Great.

Aware of what problem? Most of the Hellwig's were dealer or customer installed, they just started installing at the factory fairly recently. One post above says they have a factory installed bar and no issues. One below says cross threaded. The clunking seems to be a small percentage...certainly not the majority.

[TakeItEasy]

Originally Posted by Cfritts

I love how Joshua never comes on these and says "we are aware of that problem and working to eliminate it in production".

And now I know what else to look forward to being wrong on my Forester. Great.

Comments like that will keep reps from participating. Be thankful they are here at all.

[Pod2Vibe]

Originally Posted by bclemens

Aware of what problem? Most of the Hellwig's were dealer or customer installed, they just started installing at the factory fairly recently. One post above says they have a factory installed bar and no issues. One below says cross threaded. The clunking seems to be a small percentage...certainly not the majority.

Yup, for sure, no clunks here - Customer installed.

[Vince and Charlette]

Ran into a similar clunking when I did the CHF on my 2015 Georgetown. Turns out that moving to the aft hole in the sway bar raises the front of the bar so high that it contacts the frame...most evident in turns. Big rig alignment shop said that mine was the third Georgetown CHF that he had to undo this year. Just yesterday, I took delivery of a new Roadmaster anti-sway bar (1139-140). It's really beafy compared to the Hellwig. It costs more, but it is heavier and comes with brackets and bushings significantly larger and stronger than the Hellwig. On the other hand, I hear reports that both are a big improvement over the OEM.

[MNtraveler]

Originally Posted by bclemens

Aware of what problem? Most of the Hellwig's were dealer or customer installed, they just started installing at the factory fairly recently. One post above says they have a factory installed bar and no issues. One below says cross threaded. The clunking seems to be a small percentage...certainly not the majority.

bclemens - I don't think we have a Helwig, but the suspension clunks a lot during slow speed maneuvers. Took it to the MB dealer and they could not find anything wrong with the MB supplied equipment and also said they don't deal with issues caused by putting the heavy box onto the MB frame. The FR dealer doesn't deal with frame and suspension issues. So?


Land of 10,000 Lakes
2016 Forester MBS 2401R
Nights camped 2016: 32; RV to date: 35

[Still Kickin]

Thought about one, then thought, what if MB steps in and says, we have spec'd the sway bar as our engineers designed for the 1 ton chassis. As we all know, putting the "box" on, pushes the chassis to near limits. Then I thought, during a sway, the bar torque absorbs some, and the axle gets the rest, at the point of connection. The issue I had is, does the axle specs allow for the forces applied. The clunks are feedback to the torque forces being applied. One will never know if the heavy duty sway bars are effecting design limits, unless reports surface of axle failure start to pop up. The general engineering concept is to design it for about three times the expected force apllied in these types of application. But, as one poster has said, the "not my problem" scenario has surfaced. I'm on the sideline on this one.

[backdoctor]

Hey kickin'. That exactly what I've been noodling for that past year. I put the heavy duty sumo springs suspension parts on, which quelled the sway wonderfully, but tightened up the shock absorption considerably. Since then I've wondered about the load placed on the axle by the bump stop replacements and the structural issues of the rear of the motorhome itself with increased harshness of the ride. We've had no issues over the 45,000 km travelled since installation. But it's something I think about.

[bclemens]

Originally Posted by MNtraveler

bclemens - I don't think we have a Helwig, but the suspension clunks a lot during slow speed maneuvers.


Land of 10,000 Lakes
2016 Forester MBS 2401R
Nights camped 2016: 32; RV to date: 35

I haven't seen any "clunking" reports on anything that didn't have the sway bar. You say you "think", can you confirm? The Mercedes bar is black...If I'm not mistaken, the Helwig is dark gray with a textured finish on it.