Suspension trouble

[Pritchard]

I have a question. Can a front sway bar lose its torsion?
My '74 2.0 L has some serious steering issues. When I turn the steering wheel quickly from side to side, the front end rocks violently up and down, side to side. A couple of months ago, I posted the same question about the steering problem. It was suggested that my problem was due to a broken part in the front sway bar causing oversteer. Since then I have done the following: replaced the front struts, replaced the drop link bushings, pulled the front sway bar for inspection, adjusted the torsion bars to raise and lower the front end.
I found no damage in the front sway bar. It has the OEM 15 mm bar. Nothing is rusted, broken, or missing. The only thing I have done that has made the car driveable was to disconnect the rear sway bar.
I would like to get this car back to its go-cart-like handling. Any ideas would be appreciated.

[infraredcalvin]

Originally Posted by Pritchard

... adjusted the torsion bars to raise and lower the front end.

does this mean you turned the adjustment screw on the bottom, or did you pull the covers off the torsion bars and re index?

If you didn't already, check your t-bars, sounds like a broken one.

[Dave at Pelican Parts]

Any torsion spring can lose its torsion. The most common (by far!) mode of doing this is that the bar breaks. In our cars, the cause is very often RUST. (On a 914? Go fig!!) If you took a torch to a torsion spring, the properties of the metal would change, which would change the spring rate. If it were wound too far one way or the other, it could also change the material properties of the metal.

But to change the spring rate of a torsion spring, you either have to change the cross-section of the spring, or change the properties of the metal.

--DD

[Pritchard]

Thanks for the replies. I have not reindexed the torsion bars. I only turned the screw to change the load on the torsion bar. If it were broken, would the car rebound after pushing down on it? The rebound seems to be good and the stiffness of the front end has not changed. If anything, it is stiffer with the new struts and adjustments to the torsion setup.
The sway bar does not have any rust on it, I'm lucky. My question, I guess, is can the sway bar just plain old wear out? It is 37 yrs old now.
I got to drive the 914 to work today. What fun. It was 75 degrees and very nice. It has been a long time since I have driven the car any distance because of its rude behavior. With the rear sway bar disconnected, it reminded me of driving my mom's Caprice Classic when I was 16. Lots of swaying and delayed reaction. But it was fun anyway.

[Mike Bellis]

The sway bar may loose some of its spring tension over time but that would not cause the problem you describe. You can unbolt it and see if it improves. You should look at the bushings, tie rods and ball joints too. You shouls also check the rear suspension. If the rear is wasted it could caus effects in the front. it sounds like there should be an obvious problem. Make sure you don't have a structural problem.

[Flieger]

The anti-sway bar and/or torsion bars will not loose "springiness" or tension. The only way to do that is make them thinner, longer, make them from a different material, or heat them up with a torch. The only fatigue they would suffer from would be corrosion or a large, pre-existing crack.

[Pritchard]

I'll double check for structural damage. The change in handling was instant. The rear sway bar bushings are shot. I don't think they would cause such a drastic change though. Thanks again for the input.

[SirAndy]

Also, look for a broken, ripped, cracked suspension ear in the REAR ...

While you're in there, check the rubber bushings on the front a-arms and again the rear swing arms.
When you're putting a lot of side-load on the car, a broken or sagging rear suspension can make the front of the car bounce around as you describe.