Torsion bar fatigue

[Suzukimorris]

Hi guys I have been restoring my front end and have gone down the route of a certain popular weld on Warwickshire gas damper kit

I marked my torsion bars and rotated them around one spline, re assembled and as I lowered the car off the jack ...well it just kept going down. I mean, really down until it would have just collapsed onto the floor or sat on the tyres.Now I have ford pcd up front and have some wide ford falcon steel wheels but non the less they are about the same size as standard morris so I'm pretty sure it can't just be that.

Do we reckon I have perhaps just been a bit of tool and rotated the arms 2 splines? Or does any body know of the torsion bars losing some of the elasticity properties. It is off a 56?

Will it just be a matter of whipping the front arms back off and simply rotating them back a spline to lift until appropriate. I presume the whole point of the adjustability is to eradicate the problem of any permanent twisting of the torsion bars ever becoming a problem?

Hope that makes sense. Ta

[bmcecosse]

You obviously got your splines mixed up..... They don't weaken in any significant way.

[simmitc]

As above - did you perhaps move the spline in the wrong direction?

[Suzukimorris]

Bam, The experienced voice of reason cheers

I presume if I went the wrong way I'd have the opposite problem if it sitting like a high rider?

[mike.perry]

One spline = 1.5 in .at the outer end

[simmitc]

I presume if I went the wrong way I'd have the opposite problem if it sitting like a high rider?

Absolutely. It is possible to set it so high that you cannot line up the components, the car just rises as you try to jack the suspension arm.

[philthehill]

For consideration:-
The broached spines in the thick suspension arm are not all in the same place i.e. you can replace a thick suspension arm and you would expect the splines/arm to be positioned like for like - but they are not! The outer end of the thick suspension arm can be the same - can be higher - or can be lower than the original setting. The rear adjuster plate then comes into play.
I experienced this recently when fitting replacement BMC thick suspension arms to the original torsion bars.
Fortunately I had measured the distance from the workshop floor to the outer end of the original thick arm when disengaged from the upright and hanging free - so I was able to set the new thick arm to that measurement by using the rear adjuster plate. It all came back together quite nicely.

[Suzukimorris]

I wasn't going to say anything down to absolute shear embarrassment, but I have to confess because it might make some of you laugh. I solved the problem.... I'd taken the front arms to a friend to plug weld the mounts for the upright damper kit, and when I put them back on the car I'd put them on the wrongs sides so passenger on driver etc. Youre now thinking the muppet didn't mark down what side he took them off, oh no it's better then that, I marked them down the wrong way round!


IDIOT

[mike.perry]

We have all done some daft things at some time and missed the obvious