Suspension banging

[BLIMP]

Yesterday on our maiden journey home with the 73 Imperial, the front suspension had a substantial banging noise when encountering potholes. Actually very loud, like solid metal on solid metal, not exhaust tubing or thin stuff.
We noticed that it seemed to come more from our foot area...we also noticed that when hitting bumps [that affected both wheels at the same time] it didn't produce a sound.
So during the ride I was studying the factory service manual, and found the exploded diagram with the torsion bar isolators. I'm going to guess these are the issue.
Has anyone else encountered these symptoms, and if so, what did you discover?
I hope to get the Imperial up in the air today and do some investigating, thought I'd ask for some advice first. Thanks guys

 

[Big_John]

Check for loose shocks, especially the upper mount.

 

[Turboomni]

we also noticed that when hitting bumps [that affected both wheels at the same time] it didn't produce a sound.

Swaybar related?

 

[BLIMP]

Both very good suggestions, thank you...when I get underneath it I'll do my best to get some pics

 

[BillGrissom]

Not sure what "torsion bar isolator" is, but your Imperial may differ. In my 1965, the torsion bar has a metal hex end that fits tight in a metal hex base in the transmission cross-over beam. There is a rubber umbrella on fwd side to keep salt out (grease inside to stop corrosion). The earliest cars didn't even have that. The other end fits tight into a pivoting hex in the lower control arm. A pivot bolt allows adjusting front ride height. As in most cars, the LCA fits in a rubber bushing. When those fail, you get metal-metal rattles. A guide rod (strut rod) goes from LCA to front frame (radiator support), and there is a rubber isolator there. Otherwise, just shocks and sway bar w/ rubber isolators which could degrade and rattle. If you replace the strut rod rubber, look for the Moog improved design (rockauto).

 

[BLIMP]

Hmm, ok thank you. I was told the LCA bushings were recently replaced, but I will pay attention to those also.

 

[CBODY67]

I'll concur with the shock bushings rather than the torsion bar mounts, LCA bushings, and such.

The upper shock mount has the top threads of the shock go through it, but the rubber itself fits into a larger hole. If the upper shock nuts weren't installed tight enough to keep everything tight and firm, or too tight, the rubber can deteriorate and "leave", leaving the washers on either side of the bushing to contact metal rather than rubber.

Might be tie-rod ends or an idler arm, but those would also result in more steering slop and movement, plus decreased cornering (in the case of the idler arm).

Some Imperials had isolated k-frames in a different front stub-frame. Not sure if yours' had that Imperial-only feature.

If you notice the front torsion bar mount/interface with the LCA, that lower bushing is pressed into the LCA, not a slip fit. If it's failed, that side of the car will be lower. Any adjustment to compensate for that can make that side of the car "harder" as the torsion bar "tightened" adjustment will increase the spring rate of that "tightened" bar.

You might need to find a rough road, even a little washboard and dirt, to better isolate and diagnose the noise. Then put it on a drive-on lift, which would allow you to jounce the body and listen/look for "contact"

Please advise of your progress.

CBODY67

 

[JJ300]

Yesterday on our maiden journey home with the 73 Imperial, the front suspension had a substantial banging noise when encountering potholes. Actually very loud, like solid metal on solid metal, not exhaust tubing or thin stuff.
We noticed that it seemed to come more from our foot area...we also noticed that when hitting bumps [that affected both wheels at the same time] it didn't produce a sound.
So during the ride I was studying the factory service manual, and found the exploded diagram with the torsion bar isolators. I'm going to guess these are the issue.
Has anyone else encountered these symptoms, and if so, what did you discover?
I hope to get the Imperial up in the air today and do some investigating, thought I'd ask for some advice first. Thanks guys

But you made it home ok without breakdowns? That's good!!

 

[commando1]

"I heard a noise from underneath. What is it?"
Seriously, guys, you're giving him a diagnosis????


I give up. Seriously. I can't deal with this kind of mentalty, anymore.

 

[detmatt]

Not sure what "torsion bar isolator" is, but your Imperial may differ. In my 1965, the torsion bar has a metal hex end that fits tight in a metal hex base in the transmission cross-over beam. There is a rubber umbrella on fwd side to keep salt out (grease inside to stop corrosion). The earliest cars didn't even have that. The other end fits tight into a pivoting hex in the lower control arm. A pivot bolt allows adjusting front ride height. As in most cars, the LCA fits in a rubber bushing. When those fail, you get metal-metal rattles. A guide rod (strut rod) goes from LCA to front frame (radiator support), and there is a rubber isolator there. Otherwise, just shocks and sway bar w/ rubber isolators which could degrade and rattle. If you replace the strut rod rubber, look for the Moog improved design (rockauto).

In ‘67 the rear of the torsion bars are mounted into an assembly which is separated from the torsion bar crossmember by a pair of isolators that are like engine mounts. Mine aren’t available in the aftermarket so I had to have them rebuilt. Mine weren’t totally shot but the rebuilt ones definitely tightened things up.

 

[Davea Lux]

Have you checked the rubber snubbers on the upper and lower and lower control arms? The get hard and fail, that will cause a clank from the control arms hitting the frame on a rough road.

Dave

 

[70bigblockdodge]

Exhaust is hitting floorboard, that's my shot with my eyes closed.

 

[CHARLES374]

"I heard a noise from underneath. What is it?"
Seriously, guys, you're giving him a diagnosis????


I give up. Seriously. I can't deal with this kind of mentalty, anymore.

View attachment 175877

Why ? A member is looking for help .

 

[monaco75]

Exhaust is hitting floorboard, that's my shot with my eyes closed.

I think it’s the troll hiding in the stubframe messing with him...

 

[BLIMP]

Hey I thought I was giving a fairly decent description of the intensity of the sound, where it felt to be coming from, and my own admitted fairly uneducated guess. Didn't believe there was any harm asking a question first in case this was exactly the same symptoms as someone else experienced...I thought we all liked talking about C bodies and enjoyed pictures? I'm not trying to be an attention *****, just figured I'd share. My apologies if anyone is offended by my "mentality".
Anyways, I was able to get the Imperial up in the air, and inspect things. Shock tops look fair

Sway bar has some worn bushings, but doesn't seem too bad

It appears to be no doubt that the torsion bar crossmember is the issue.

I'm able to push up on it and the isolators are completely separated from the crossmember...in fact I can bang the crossmember into the transmission tailhousing.

Thank you to the people that spent time sharing their diagnosis, it's appreciated.
Paul

 

[detmatt]

Yep, there’s your problem! You’ll need these guys to rebuild those.
Nors Vulcanized Motor Mounts & Rubber Products - Then and Now Automotive

 

[commando1]

Why ? A member is looking for help .

They think they are helping but they are only making the waters muddy.
There's a dozen questions that needs to be asked first but whenever I ask them so that an intelligent troubleshooting process can be started, everybody becomes Horseshack.
This is why I rarely help anymore.

Anyways, I was able to get the Imperial up in the air, and inspect things.

It appearsto be no doubt that the torsion bar crossmember is the issue.

Yep, there’s your problem! You’ll need these guys to rebuild those.
Nors Vulcanized Motor Mounts & Rubber Products - Then and Now Automotive

THAT'S how you help someone. Thank you, Matt.


FML

 

[BLIMP]

Yep, there’s your problem! You’ll need these guys to rebuild those.
Nors Vulcanized Motor Mounts & Rubber Products - Then and Now Automotive

Perfect, exactly the information needed, thank you Sir

 

[DocMcNeedy]

Hey I thought I was giving a fairly decent description of the intensity of the sound, where it felt to be coming from, and my own admitted fairly uneducated guess. Didn't believe there was any harm asking a question first in case this was exactly the same symptoms as someone else experienced...I thought we all liked talking about C bodies and enjoyed pictures? I'm not trying to be an attention *****, just figured I'd share. My apologies if anyone is offended by my "mentality".
Anyways, I was able to get the Imperial up in the air, and inspect things. Shock tops look fairView attachment 175885 Sway bar has some worn bushings, but doesn't seem too badView attachment 175886 It appears to be no doubt that the torsion bar crossmember is the issue.View attachment 175881 View attachment 175882 I'm able to push up on it and the isolators are completely separated from the crossmember...in fact I can bang the crossmember into the transmission tailhousing.View attachment 175883 View attachment 175884

Thank you to the people that spent time sharing their diagnosis, it's appreciated.
Paul

You're doing great job, Paul...glad you made it home safe with BLIMP...keep on with the pics and issues...and don't worry--->..."I'm the unequivocal narcissistic forum attention *****..".

 

[detmatt]

You are quite welcome my friends.