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Broken torsion bar ... welded

Posted: Sat Mar 31, 2012 11:56 am
by MieRo
Hi, we're a Belgian couple traveling in a L300 4WD from New York to Rio De Janeiro.
After 7 monthes and 30.000km we made it to the Cordillera Blanca in Peru.

Doing a bumpy mountainroad yesterday, suddenly we heard a loud 'snap'. And there it lay, in a dustcloud behind us, the left torsion bar, broken. Slowly winding our way further down from 4000m altitude, we found a mechanic specialized in suspensions, what a 'lucky' coincidence.

The mechanic said he could order a new torsion bar, but it would be very expensive (and I doubt he would find the part anyway in Peru). Or he could weld it, he had done it a couple of times before and was pretty sure it would hold. The front shocks were dead, which was probably the main cause. We replaced the shocks with spare Monroe Adventure 4x4's I brought, which are quite stiff, and I hope will take some load off the bars. Or is this wishful thinking?

We've got 2 more months to go with the car, and I think less than 10.000km. So we don't really want to spend to much money on the car anymore. What do you think, will the bar hold? What if it doesn't, and snaps again while we're going 90km/h? Dangerous?

I included 2 attachments of the broken, and welded bar.

Our blog (in dutch);
http://miero-amerika.blogspot.com/
http://www.drivetheamericas.com/wiki/robin-and-miet

Re: Broken torsion bar ... welded

Posted: Sat Mar 31, 2012 12:34 pm
by thedjjack
Depends how it was welded (did they pre-heat the weld? what did they weld it with?).....It is spring steel so any heat is going to change the spring properties...

the weld will most likely be a weak point...a spring shop should be able to re-heat treat the properties (but the fact it broke indicates a tired piece of metal)...

I would think it should hold for 10,000km but I would not want to be driving at 90km/h if it broke...

I would think a used on shipped from Mexico would be not to much $$$ or maybe a more common torsion bar could be used easier to weld the the frame to hold a different bar then modify the bar.

Best of luck enjoy the world....

Re: Broken torsion bar ... welded

Posted: Sat Mar 31, 2012 1:36 pm
by jessef
I would say check and make your bump stops longer so that if the torsion bar does fail again, that it will not cause severe drop in the front end. You will loose up travel but the safeguard is better.

If that breaks at 90km/hr you can be in serious trouble depending on the road.

A used torsion bar is cheap here. If you have time on your hands, having someone ship one down to you may be helpful.

For welding sprung steel, preheating it will help the weld not to crack. The torison bar has some additional carbon content in order for it to have been used as spring. After welding, bury the part in dry sand or oil dry and let it cool.

With the weld hopefully it was done well and lasts you the rest of the trip. Good vibes.

Re: Broken torsion bar ... welded

Posted: Sat Mar 31, 2012 2:58 pm
by yojimbo
He's done a good job of that, did he weld around the ring or did he leave it? The load should be spread pretty well, and the new shocks will help the bar be worked less. Its certainly a workable solution, long term? Good question.

Re: Broken torsion bar ... welded

Posted: Sun Apr 01, 2012 7:11 am
by MieRo
Thanks for the replies, I feel a little more confident.
The mechanic welded the bar with special (and expensive) electrodes. He made me pay a little in advance so he could go buy these because he only had regular ones.
Also he let the TB cool down a night before reïnstalling it, so I guess he knew what he was doing.
Cross fingers it holds!