What the hell was that noise?

[mark 74 carrera]

I was in the middle of a hard acceleration from third, about to shift to fourth, when I heard this loud bump. It sounded as if I had run over something in the road. I immediately slowed down and checked everything.

Definetly no loss in power. Engine runs great. Nothing wrong with the transmission or shifting(not the clutch)

As I got back in the car and continued to drive, I did notice a rattle on rough road surfaces.

I'm thinking suspension or CV joints. Although I heard no clicking usually associated with CV joints. When I got home, I noticed the car was riding lower on the passenger side rear. That is where I heard the sound. Normally, the tire is even with the wheel well and now it is about 1"-1&1/2" inside the wheel well.

Has anyone ever experienced a broken torsion bar? Could the rattle have been the shocks "bottoming out"? Is there a way to test a torsion bar without removing the whole assembly? If the bar is broken, how do you remove the portion of the bar that is still splined into the car?

The tires never rubbed the wheel well. There appears to be no damage that can be readily seen. I always wanted to adjust the ride height of my car, am I getting ready to have the opportunity to do just that?

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Mark Isaak
'74 Targa

[This message has been edited by mark 74 carrera (edited 10-09-2001).]

[pwd72s]

"It sounded as if I had run over something in the road"

Maybe that was indeed it? Not all road debris is readily seen.

[nhromyak]

It sounds like one of your bolts on the trailing arms might have sheared off.

I would check all trailing arms for bolts/holes. Check left vs right trailing arms for any bolts, nuts and holes that might be missing or one side not having one where the other side does have one (that was confusing to me too).

Good Luck!

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Nick Hromyak
'85 Carrera 7 & 9 Fuchs
Havin' Fun in Sacramento

[Superman]

I have never heard of a torsion bar breaking but nothing is impossible. Raise the rear of the car and manually try to push the wheel up into the wheel well. the shock does nothing whatsoever to suspect the car. Its only job is to keep the suspension from moving too far too quickly. The torsion bar is the ONLY thing holding up the car, so if you can manually push the wheel into the wheel well, your torsion bar has failed.

Yes, you will be able to remove it if necessary, but removing the one on the other side and driving the broken one out with a piece of pipe. Yes, this would give you an 'opportunity' to change ride height, and install stiffer bars, if you like. And replace bushings, which are worn out on cars as old as yours, or mine.

I'd certainly give the car a complete inspection before I trusted it again. Suspension and brake problems are NOT things I put off until a more convenient time

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'83 SC

[Jack Olsen]

Rear sway bar mounts?

[Joe Bob]

I agree with Jack....rear sway bar.

BTW, the new owner of my 914/6 3.0 reported an aftermarket torsion bar failure...it was the front one and it went POW....

[ClayMcguill]

I'm thinking rear tosion bar...the lower ride height on one corner, plus the rougher ride on some road surfaces points me in that direction.

True, the torsion bars are the only springing medium on the chassis-but-the shock on that corner is probably compressed as far as it will go, thus preventing the suspension from collapsing completely on that corner.

Support the car on jackstands, unbolt the shock from the control arm, and THEN see if you can easily compress/extend the control arm through its travel-if there's hardly any resistance at all..well, viola, you've found your problem.

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Clay McGuill '66 912, '97 Jeep Cherokee, '70 Ford Bronco www.geocities.com/the912guy

[john70t]

If it was the torsion bar, wouldn't both sides "bottom out" evenly ?- it's one bar across with two arm attached at the ends (unless I'm missing something). Best o' luck

[ClayMcguill]

Nope..there are 2 rear torsion bars-each is held at their inner end at the center of the housing in a fixed, splined fitting, and extend outward, fitting into splined holes in the spring plates.

So, with just one being broken, only that corner of the car would droop.

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Clay McGuill '66 912, '97 Jeep Cherokee, '70 Ford Bronco www.geocities.com/the912guy

[This message has been edited by ClayMcguill (edited 10-09-2001).]

[rcilurso]

I have only seen one torsion bar break. But I've seen it. Don't count it out.

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rj cilurso
87 911 targa

[orbmedia]

Yea, I saw a torsion bar break on a 3.2 Carrera at Lime Rock this year. It was a stock low mileage car. But one end was sagging alot in the rear wheel well and nothing looked wrong from the outside so it must've been the torsion bar inside the torsion housing had broken or something.

[wckrause]

Would a broken sway bar, or sway bar mount cause one side to drop?

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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

[speeder]

Not to scare the ***** outta ya, but I have seen the inner(splined) mount fail from rust that was not externally visible on an early car. This is an expensive fix.

I would definitely pull rear sway bar on that side- when you get spring plate unbolted try to turn it by hand- if no resistance then hope that bar comes out in two pieces. Sway bar mount would not affect ride height.

[speeder]

Correct that- if inner mount fails, entire rear would drop,(one welded mount for both sides). Whew! Start wrenching- you should find problem quickly!

[mark 74 carrera]

Thanks for all the info. I have not had a chance since Sunday to even look at the car. You guys have given me plenty of things to check.

I'll keep you updated.

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Mark Isaak
'74 Targa

[mark 74 carrera]

The sway bar people have it!!! Looked up under the car in the light of day and the sway bar is hanging down. It is still attached just detached from the circular bushing mount.

I guess I am going to get a little lesson in rear sway bar repair. Wish me luck!! Anyone have any pointers or "while you at it" add ons?

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Mark Isaak
'74 Targa

[ClayMcguill]

Well, I was close....

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Clay McGuill '66 912, '97 Jeep Cherokee, '70 Ford Bronco www.geocities.com/the912guy

[speeder]

Boy, I am humbled here. How does the sway bar hold up the car?

[Jack Olsen]

I hate to threaten my place on the podium, but the sway bar mount could have snapped as a consequence of the torsion bar (or its fitting) breaking loose. There still might be trouble upstream.

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Jack Olsen
My Rennlist page • My Pelican Gallery page • My Porsche Owners Gallery page

[Superman]

The sway bar does nothing to hold up the car. You can take the sway bar completely off the car and the only thing you'd notice is that the banging noise would be gone. Unless the sway is now the ONLY thing holding up the car.

If one side is riding verifiably, noticeable lower now, then I still believe there is a broken torsion bar. I am usually quick to advise "Aw heck, just drive the car and quit worrying," but this is not one of those cases. If this were my car, I'd take the sway bar off (broken anyway), I might take the shock off as well, and I'd try to push the wheel up into the wheel well with my big strong arms. If I was able to do that, I'd get a pair of hollow 28mm sway bars for the rear and some new bushings and I'd install them all. Not the plastic bushings, but the fancy new rubbery ones that last really long. I'd hang my broken sway bar in the garage as another conversation piece. I like to keep those parts that failed violently.

At any rate, the point I am making is that if your torsion bar is broken, you will know that by just playing with it manually.

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'83 SC