Saxo broken drive shaft

Honest John Back Room » Technical matters
View Threaded
Sat 12 Aug 2006 23:49
Saxo broken drive shaft - Robin the Technician
Hi Guys,
My niece has just had a drive shaft on the o/s of her 'w' reg Citroen Saxo break off. I was surprised to see it was tubular rather than solid and it had ended up like a corkscrew. Also the joint attached to the gearbox had been nearly yanked out causing oil spillage. The car has never been involved in an accident so I'm at a loss as to the cause. A local breakdown firm who stopped to assist as I arrived knew exactly the problem before lifting the bonnet and said it was a common fault.

Anyone else out there heard of this and know the cause?

Your divine guidance is, as always greatly appreciated


--
These are the views of Robin the Technician with 35 years in the trade. I fix, therefore I am...
Reply | Report as offensive | Link
Sun 13 Aug 2006 00:30
Saxo broken drive shaft - Number_Cruncher
There are two obvious possibilities which spring to mind, as you describe a predominantly plastic failure mode;

1) The yield stress of the steel was not up to the requirement - i.e., the shaft was made out either the wrong steel, or a bad batch of the right steel.

2) The shaft section is inadequate - i.e., a design problem.

It makes a lot of sense to make shafts which transmit torsion from tubular sections rather than from solid - the material near the centre of a solid shaft contributs almost nothing to the torsional stiffness of a shaft (the torsional stiffness goes as radius to the power of four. The rotational speed at which shafts whirl is also increased by using a tubular shaft rather than a solid one.

Number_Cruncher
Reply | Report as offensive | Link

We give you the low down on how to save on insurance, little-known tricks and tips, what insurance groups mean and how to use insurance aggregators to beat insurers.

Insurance group finder and how to save on insurance