torsion bar losing it's tension

[bluesman41]

can a torsion bar lose it's tension? this is the second time my 68 roadrunner drag cars left bar dropped down to the stop a guy I know at Les Schwab said they can go bad.
I put used mopar performance bars on have had nothing but issues with them so today I bought some .84 bars from firm feel. I hope they cure my issues along with work better at launch!

 

[Mopars & Missiles]

What usually causes this is the rear torsion bar mount twists in the crossmember due to rust problems.

 

[dvw]

My Drag cars always loose tension on the torsion bar. I make a measurement of the front fender lip to the ground. This allows to readjust periodically without guess work. That being said I use 6 cylinder bars which are thin. A torsion bar is nothing more than a straight coil spring. The material is still being twisted back and forth. So like any spring they can lose tension with use.
Doug

 

[Darthomas]

I remember having a shop repair a ripped/rusted out torsion bar socket,
and even after giving them documentation about getting it indexed properly, and how it worked, when I went back, they told ME something HAD to be wrong with the bar, because the height could not be brought up to anything beyond barely resting on the bumper stops.
I said, "sorry, you're going to have to grind this all out, and do it over."
They did, and they ate the lost time.
It's nice to win one once in a while.

 

[mmissile]

I don't think anybody "won" in that story.

 

[66Satellite47]

I remember having a shop repair a ripped/rusted out torsion bar socket,
and even after giving them documentation about getting it indexed properly, and how it worked, when I went back, they told ME something HAD to be wrong with the bar, because the height could not be brought up to anything beyond barely resting on the bumper stops.
I said, "sorry, you're going to have to grind this all out, and do it over."
They did, and they ate the lost time.
It's nice to win one once in a while.

In my experience, the adjustment CAN bring the arm well off the bumper. Sounds like BS. Having said that, T bars do sag over time.