Register now to gain access to all of our features. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more. If you already have an account, login here - otherwise create an account for free today!
Do Torsion Bars Wear?
Posted 14 February 2004 - 04:35 AM
My 205 seems a bit bouncey even with new shocks on. It has a 309 rear beam.
I was begining to think I had maybe put the ARB in badly and it was unsettling the set up. Like when I come over the crest of a hill and the weight comes off the rear it seems to lift more at one side than the other.
I did recondition the beam myself recently and have put new stubs and bearings in it and it has no play so can't be that.
I have tried different ride height settings and it is always the same.
I'm overseas and haven't driven it in about a year but want to sort it when I get back in April!
Posted 14 February 2004 - 07:45 PM
Not sure what happens to the torsion bars when they get old/worn though.
Posted 14 February 2004 - 09:05 PM
Think I'll try to reset everything when I get back and maybe leave the ARB disconnected to see if it has any effect.
Another thought is that the torsion bars are not torqued up evenly. Overtightening them can cause the swinging arm to stiffen. Maybe one is too tight
As a second test I'll put some other shocks on.
Posted 14 February 2004 - 09:27 PM
Posted 15 February 2004 - 12:41 PM
I think he means age and become weaker rather than slacker.
the torsion bars themselves shouldnt wear as the splines are a very close fit
Posted 15 February 2004 - 03:10 PM
any metal specialists out there??
Posted 15 February 2004 - 03:35 PM
Of course it is under constant forces so there is going to be a good amount of cyclic torsional stresses being applied but I cant really see that it would be at a level to actually degrade the metal as it would have to breach the yield strength of the metal to have any effect on how 'elastic' it is and youd definatly notice if this was to happen. Also I doubt peugeot would have used any dimensions/compositions etc where this wouls be likely to happen as there should be a resonable safety area built in top prevent this.
So Id say it was unlikely that the bars would 'weaken' with age unless there was a serious application of force at some point although technically they should have been able to cope i would have thought.
P.S. Im certainly no specialist in this area but Im just using my basic materials knowledge here, obviously youd need to do proper testing to accurately predict the failure life of the torsion bars but I would have thought it is unlikely.
Posted 15 February 2004 - 04:16 PM
A lot will depend on how the the bars are heat treated.
Does anyone remember the front end of Morris Marinas??? They used torsion bars and the front used to sag badly after a few years. Engineers have found better grades of metal to use......also better methods of treating it. It just means the sagging will take longer.
Posted 15 February 2004 - 04:43 PM
How old is the car ?
Posted 15 February 2004 - 04:50 PM
Posted 15 February 2004 - 06:00 PM
That won't be the torsion bar that has seized as that isn't possible; the torsion bar is a metal bar with 2 fixed end points. It will have been the trailing arm that could sieze.
I've also heard about seized torsion bars, and I guess that has with age and wear to do as well.
EDIT: I reread it and of course the torsion bars can sieze! Insomuch that they can become siezed in their splined fittings when you're trying to remove them. But for normal suspension operation the torsion bar can't "seize".
Posted 15 February 2004 - 06:03 PM
Posted 16 February 2004 - 07:33 AM
That's what I was thinking.
Does a coil spring sag......course it does. So why shouldn't a torsion bar spring sag over time???
I put the 309 axle on when the car had around 80,000 miles which was about 9 years ago and it now has 207,000 miles on it. Plus I'm not sure how many miles were already on the axle.
The rebuild I did was just to replace the parts that wear like the bearings and bushes.
It was also unused for long periods. Like when I was travelling for over a year and it sat in the garage up on blocks to prevent tyre flat spots. And since I got a second car 4 years ago.
Posted 16 February 2004 - 02:53 PM
Posted 16 February 2004 - 08:57 PM
Posted 16 February 2004 - 10:58 PM
Posted 18 February 2004 - 11:20 AM
Just to add to that logic (which I'd agree with ) torsion bars and coil springs actually work in almost identical fashions: The coil spring is just a torsion bar wound into a cylindrical shape and it provides its elasticity by twisting the spring wire in the same way that a torsion bar does.
Does a coil spring sag......course it does. So why shouldn't a torsion bar spring sag over time??? They are both made of similar spring steel. Obviously the torsion bar isn't wound like a coil spring is.
I've had to replace both coil springs and torsion bars on old vehicles because they have "worn out" ie: the material is beginning to yield. This usually happens after 40 or 50 years or so
Posted 18 February 2004 - 03:32 PM
the torsion bar is on a picture here
Well Right at the end where the shocker is on the drivers side i think there called Radius arm bearings acording to a MOT man! and he said mine have worn ,
So when u look at the back the one wheel is at a angle so its rubbing the ache at the top!
Does anyone know where u can get a re-con torsion bar ?? at all ??
I know the Radius bearing wear down lol
Posted 18 February 2004 - 08:19 PM
Does anyone know where u can get a re-con torsion bar ?? at all ?? [sad.gif]
I know the Radius bearing wear down lol
By re-con torsion bar I assume you mean re-con rear beam! If you do a search there will be plenty of threads about rear beams.
Posted 18 February 2004 - 09:13 PM
Edited by puggti, 18 February 2004 - 09:13 PM.