Do Torsion Bars Wear?

[Guest Sgoaty]

It looks like the left hand bar is fixed at the right hand mounting and off center on the left hand trailing arm but as the trailing arm moves up and down the left hand splined hole moves off center. this is how it looks to me anyway if anyone has diagrams it would be helpfull. Sorry for the thread Hijack

Edited February 22, 2004 by Sgoaty

[Adi 0]

as the trailing arm moves up and down the left hand splined hole moves off center

 

Yes but because the torsion bar is mounted in the arm near the pivot point on the axle.....the torsion bar doesn't move up and down a great deal.

[pug_ham 245 3 Cars]

Yes the bar twists......thats how the spring action works. But other than that, the bars stay very straight.

Because the torsion bar twist's over it's length won't it be stronger than a spring & have a lower tendency to sag like old springs can?

 

The twisting motion will be harder to sustain a twist in a bar than the spring steel going weak because of the difference in thickness. It is a lot harder to twist a piece of spring steel permanently than it is to compress a spring & it to decrease the overall free length of it IMO.

 

Graham.

[Adi 0]

Because the torsion bar twist's over it's length won't it be stronger than a spring & have a lower tendency to sag like old springs can?

 

A coil spring works in a similar manner. The spring steel twists through its length supply the resistance. Any sagging effect really comes from how the spring is made. Eibach tend to cold roll thier springs.....and as a result....there is a 10 year guarentee on them.

On the other hand there was a report of GMC's spring snapping after only 12 months and 10000 miles.

 

It is a lot harder to twist a piece of spring steel permanently than it is to compress a spring

 

It all depends on how long the lever is to twist the torsion bar. That is what determines the rate of a torsion bar.

As you mentioned.....the spring steel used on a torsion bar is thicker.....and as a result you would expect it to last longer.

[Guest Sgoaty]

Yes but because the torsion bar is mounted in the arm near the pivot point on the axle.....the torsion bar doesn't move up and down a great deal.

So it does bend.

[Adi 0]

So it does bend

 

The only real way you can see what happens is to remove the rear dampers and get someone to bounce the rear suspension. Then you'll see how the torsion bars move.

[C_W 3 1 Cars]

The movement is pretty wierd though isn;t it! You imagine them to twist in a straight line (like the rear anti roll bar) but this isn't possible how they are laid out.

[chesney 0]

SGOATY,

 

That inlet manifold looks a lot cleaner than the one I sent you last year!

 

Did you ever use the 16v head I sold you?

[Adi 0]

The movement is pretty wierd though isn;t it! You imagine them to twist in a straight line

 

Yes the movement isn't as you'd expect. There is a certain amount of deflection. But I just wouldn't describe it as bending. This is where the English language can be difficult. The best way to understand the movement is to see it.

[Guest Sgoaty]

That is the manifold chesney mate and the head is still sitting in my garage