Rear Beam Problem

[bearmach 0]

Hi

I am doing a rebuild on my rear beam and all going well untill i painted the anti roll bars and forgot to label, what side they came off, do they have to go on the same way or can they go either side.

[Tom Fenton 1,540]

From new they had rings on to denote which went where, but to be honest if you have painted them so you can't tell, I would just refit them and not lose any sleep over it.

 

By the way, the two bars that run outside the tube are the torsion bars, these provide the spring for each rear wheel. The one bar thru the middle is the anti roll bar.

[Anthony 1,002]

I assume you mean the torsion bars (the two bars on the outside of the tube)?

 

If so, whilst in theory they're handed, it should be fine to use them on either side.

[bearmach 0]

I assume you mean the torsion bars (the two bars on the outside of the tube)?

 

If so, whilst in theory they're handed, it should be fine to use them on either side.

 

thanks yes i do mean the torsion bars, having a blonde day,

[SurGie 54]

If so, whilst in theory they're handed, it should be fine to use them on either side.

 

When you say "it should" does that mean its not a guarantee it will be fine ?

 

My theory on this is if the torsion bars have been on one way all its life, (ie, Peugeot's painted rings way) then the suspension beam

would work better as it did before the rebuild, springing the same way again. There's the splines also that have been in the arms rusting etc, im

sure this could cause some problems ? (I dont know form sure as im not a professional beam builder)

 

Would the effect of the spring when its attached the other way round be more stiff, or would the temper of the bar make no

difference at all ?

 

 

Cheers George

[Anthony 1,002]

There are no guarantees in life (well, besides that eventually we'll all slip from this mortal coil I 'spose)

 

I have seen plenty of beams that have the bars fitted the wrong way around, and I've seen some that have (for example) two passenger side bars fitted, and there has been no obvious ill-effect from what I could tell. I'm not a metalurgist (sp?) so I don't know for definate what the effect of a bar being twisted in one direction for a number of years and then reversed would be - hence the "should" - but so long as you're doing the same with both bars (ie fitting them back to front) I can't see if being an issue, and as said, have never seen nor heard of any problems.

 

Aftermarket uprated torsion bars aren't handed and can be fitted either way around.

 

Splines won't be an issue either way around, and you'd clean off all the corrosion and rust prior to fitting anyway. If the splines have worn and it's no longer a snug fit, then they need to be replaced.

[Tom Fenton 1,540]

The steel needs to be tempered so as to give the property that it will operate within its elastic region. It needs this to work as a spring, as otherwise it would not hold the car up.

Because of this tempering, it is resistant to fatigue. It does not matter in which direction the loading is applied, as the material acts in the elastic region. Of course the theory and practise are often different, as touched on in another thread a few months ago, the torsion bars do not operate in pure torsion they also have a small bending load applied. Plus who knows what effect millions of cycles will have. But from experience, as I said above, I don't worry about it.

Edited February 5, 2010 by Tom Fenton