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'87 W124 300TD, '85 W123 280E
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Discussion Starter #1
Guys,

My front passenger side swaybar hanger has now broken (sheared through just above the bar) for the third time in the same number of months.

After the second break I replaced the front struts. I've checked the front end for loose connections or play but I can't see or hear anything abnormal.

These breaks always occur after driving stretches of rough "under construction" pavement. As a matter of fact the three instances have all happened within a few miles of one another and unfortunately on an unavoidable highway.

Could there be some reason why this one component keeps failing repeatedly? What are the consequences of driving with the hanger broken?

Thanks.
 

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Premium Member
'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,378 Posts
I've broken mine twice now. The first time I wasn't paying attention to the road situation. The second time I came out of an alley in pitch dark (with old eyes) and abruptly launched into a different elevation onto the paved road. So....I'm guessing it's your road situation rather than unusual component failure. Just be sure to buy an OE hanger and not Chinese.

However, make sure your sway bar bushings are in perfect order as well, because they are supposed to absorb the majority of the sway bar shock. Also, make sure your struts aren't worn out...along with your top strut mounts and bump stops. It's a 'system'; make sure it's all 100% before you blame just one part.

Kevin
 

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E320/E250 Bluetec Ford F350 6.7l
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Mine broke at the frame mount and I rewelded it. The crack looks like result of wrong heat treatment. The steel is overdone and shatters like glass... almost ;)
Rewelding improves the bracket as it makes the steel softer and more flexible.
 

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1996, A124, E320 Sportline Cabriolet x 2
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1,555 Posts
Guys,

My front passenger side swaybar hanger has now broken (sheared through just above the bar) for the third time in the same number of months.

After the second break I replaced the front struts. I've checked the front end for loose connections or play but I can't see or hear anything abnormal.

These breaks always occur after driving stretches of rough "under construction" pavement. As a matter of fact the three instances have all happened within a few miles of one another and unfortunately on an unavoidable highway.

Could there be some reason why this one component keeps failing repeatedly? What are the consequences of driving with the hanger broken?

Thanks.
Got a picture of where it broke ? Cracks in these components are usually fatigue related.

If you can heat the weld area after welding to a very very dull red color, at night, about 650 Deg C and keep it there for 10 - 15 seconds then bring it down very slowly to 500 DegC (no color) then let it air cool you will stress relieve it & soften it somewhat. I think it is breaking because welding usually hardens steel, especially at the toe of a weld and through fatigue it will fail much earlier than without welding. It also very much depends where the weld is and what, if any, stress raisers are present; notches and the like.
Welding and cooling quickly after welding (common on thin sections) will tend to harden most steels. I am guessing because the bracket is formed it won't be quenched and tempered from factory.

Need a picture to add more.......
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,378 Posts
Mine broke at the frame mount and I rewelded it. The crack looks like result of wrong heat treatment. The steel is overdone and shatters like glass... almost ;)
Rewelding improves the bracket as it makes the steel softer and more flexible.
Not true at all. You're fishing if you think welding changes the metallurgy for the better. My last bracket my son welded and he's a pro. It broke again right next to his weld-just a different line. If your theory was true, it wouldn't have broken again in the same area.

These brackets aren't that expensive, just buy another OE, or have a shop make you a few out of better steel.

Kevin
 

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Premium Member
'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,378 Posts
Got a picture of where it broke ? Cracks in these components are usually fatigue related.

If you can heat the weld area after welding to a very very dull red color, at night, about 650 Deg C and keep it there for 10 - 15 seconds then bring it down very slowly to 500 DegC (no color) then let it air cool you will stress relieve it & soften it somewhat. I think it is breaking because welding usually hardens steel, especially at the toe of a weld and through fatigue it will fail much earlier than without welding. It also very much depends where the weld is and what, if any, stress raisers are present; notches and the like.
Welding and cooling quickly after welding (common on thin sections) will tend to harden most steels. I am guessing because the bracket is formed it won't be quenched and tempered from factory.

Need a picture to add more.......
Again....it isn't worth the effort. Just buy an OE bracket or have a machine shop make you some brackets out of better steel. There is only one bend in the bracket and you can even gusset if you desire. Mine has broken in the same place on the same side, twice now. The sway bar on the 4matic wagon though, is a bit of a different animal on the end assemblies....which are like $80 ea OE if I remember correctly.

Kevin
 

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'87 W124 300TD, '85 W123 280E
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Discussion Starter #7
Ok, so it sounds like it's just an inferior replacement part I keep getting...

What could happen if you drive for too long with the bracket broken?

The first time this happened I called AAA and had it on a flatbed to my local shop. The other two times I've driven slowly and cautiously to the shop.

The big issue was the sound of the bracket scraping and snapping over bumps and around turns. Could this lead to failure of the other bracket prematurely? Could it cause stress damage to bushings or clamps?
 

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'87 300TD/'90 300D/'94 Quattro/'89 Vanagon TDI/'01 EV Weekender VR6
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I've never understood MB's thinking with the design for these things. A swaybar bracket should never break, yet these do it all time. I had one break a while back, so I welded in some gussets and it was fine until I removed it for a new one--I didn't like the idea of one side flexing at a different rate than the other. I think I'd like to redesign them to be more like these, which apparently come with a mega oversized swaybar kit that was once available in Japan.

 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,378 Posts
I've never understood MB's thinking with the design for these things. A swaybar bracket should never break, yet these do it all time. I had one break a while back, so I welded in some gussets and it was fine until I removed it for a new one--I didn't like the idea of one side flexing at a different rate than the other. I think I'd like to redesign them to be more like these, which apparently come with a mega oversized swaybar kit that was once available in Japan.

Yeah well, that's the friggin' way they ought to look.:thumbsup: But short of that, just have a good machine shop make some out of better steel with some gussets and you're done.

Kevin
 

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1996, A124, E320 Sportline Cabriolet x 2
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Again....it isn't worth the effort. Just buy an OE bracket or have a machine shop make you some brackets out of better steel. There is only one bend in the bracket and you can even gusset if you desire. Mine has broken in the same place on the same side, twice now. The sway bar on the 4matic wagon though, is a bit of a different animal on the end assemblies....which are like $80 ea OE if I remember correctly.

Kevin
Orr, I don't know Kevin, if you've gone to the bother of welding it all you need to do is heat it afterwards with an accetylene set and should be good to go - especially if you are nowhere near a Dealer or a wrecker - otherwise you might be right.......??

Don't think it will do damage if you drive around for a while, just makes a noise and the car will be a little less stable directionally, that's all. Nothing else should break as a result, but it really is good to get it connected properly.
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,378 Posts
Orr, I don't know Kevin, if you've gone to the bother of welding it all you need to do is heat it afterwards with an accetylene set and should be good to go - especially if you are nowhere near a Dealer or a wrecker - otherwise you might be right.......??

Don't think it will do damage if you drive around for a while, just makes a noise and the car will be a little less stable directionally, that's all. Nothing else should break as a result, but it really is good to get it connected properly.
Yeah, trust me...I know how to heat-temper steel. I would rather improve the design with better steel and gussets than temper their cheap steel. Maybe even just the gussets would make these bullet proof. As Casey said, they shouldn't ever break unless you launched your front end.

Just as an FYI, on a 4matic because the end assemblies are made to flex, it would be a bad idea to drive around with a bracket broken. It would prematurely wear out that end assembly-learned from experience there.

Kevin
 

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'87 300TD/'90 300D/'94 Quattro/'89 Vanagon TDI/'01 EV Weekender VR6
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I think every 124 I've seen in a P n' P has had at least one swaybar bracket broken. It's a dumb design
 

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1996, A124, E320 Sportline Cabriolet x 2
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Yes! I've got 200,000 kms on a Sportline Cabbie and still good to go. Maybe Sportlines last a little longer with less suspension travel??
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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I think every 124 I've seen in a P n' P has had at least one swaybar bracket broken. It's a dumb design
It is...the brackets look like they were designed as an afterthought. I would be happy to pay more (I usually do on 4matic parts), because the 4matic brackets are beefier....they are not.:(

I think rather than weld/buy another bracket, I'll take one down to my machinist buddy and fab up some better brackets. Pics to follow eventually......

Kevin
 

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E320/E250 Bluetec Ford F350 6.7l
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Not true at all. You're fishing if you think welding changes the metallurgy for the better. My last bracket my son welded and he's a pro. It broke again right next to his weld-just a different line. If your theory was true, it wouldn't have broken again in the same area.

These brackets aren't that expensive, just buy another OE, or have a shop make you a few out of better steel.

Kevin
Buying new bracket risking the same manufacturing defect is not the best option IMHO.
You don't understand steel heat treating process. Over-treated steel is gaining high hardness, but looses flexibility and that what makes it crack in shatter mode.
It is very common the welded heat treated steel cracks next to the weld and any professional welder would know about it.
Such a steel should be warmed up for welding to avoid the metal heat stress. I did not go that far, but I made several smaller welding passings, what warmed the steel and lowered the stress. So far my bracket is holding.
 

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'87 300TD/'90 300D/'94 Quattro/'89 Vanagon TDI/'01 EV Weekender VR6
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Yes! I've got 200,000 kms on a Sportline Cabbie and still good to go. Maybe Sportlines last a little longer with less suspension travel??
Interesting theory. Anecdotally, I can state that neither of my 124s sitting on H&Rs has popped a swaybar mount.
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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Buying new bracket risking the same manufacturing defect is not the best option IMHO.
You don't understand steel heat treating process. Over-treated steel is gaining high hardness, but looses flexibility and that what makes it crack in shatter mode.
It is very common the welded heat treated steel cracks next to the weld and any professional welder would know about it.
Such a steel should be warmed up for welding to avoid the metal heat stress. I did not go that far, but I made several smaller welding passings, what warmed the steel and lowered the stress. So far my bracket is holding.
I understand a lot more than you think and your ability to use common English and the right nomenclature terms, sucks. Inspector has it correct about heat tempering, but I have no idea what the hell you're trying to say.

Kevin
 

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A good preheat will slow the cooling rate after welding and hence make the finished product softer, but because the bracket is thin (doesn't hold much heat anyway) I thought sweating it afterwards would be they way to go. Either way will give similar results I think.......
 

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I understand a lot more than you think and your ability to use common English and the right nomenclature terms, sucks. Inspector has it correct about heat tempering, but I have no idea what the hell you're trying to say.

Kevin
Steel heat-treatment is an art lot are trying to achieve and fail.
Why no other blacksmiths can copy the Samurai swords quality regardless several hundreds of years?
Heating steel after the welding will lead to loss of all heat treatment, what will prevent future cracks, but the bracket will bend easily.
I did learn metallurgy in different language so not always know proper English names, but I am trying to make the explanation easy to understand to people who did not study mechanics, so sorry it is not working for you.
 

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That's right. But I don't think these brackets are heat treated from Factory. I think they are essentially in the normalised condition with a little bit of cold work maybe, therefore you loose no strength but gain ductility till it work hardends and fails from fatigue again. The design is not the best.
 
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