Suspension Struts

[keithj]

I have been pondering recently how much longer the six years of interest and enjoyment that driving my '94 2.0 Si turbo XM has given me will continue. I have the impression that most everything that goes wrong is fixable, but that suspension strut failures are economically if not technically fatal! My gloomy expectation was confirmed recently on discovering that Pleiades don't supply XM Struts.

Does anyone know a reliable source of supply for new or good second hand struts? Has anyone tried sourcing them in France?

[noz]

Keith,

That is indeed a worrying statement. The failure of a strut is certainly fatal if you can't replace it.

In my experience the struts are likely to fail at two main points.

1) At the junction between the sphere neck and the strut end. The mixture of steel and aluminium alloy sets up a galvanic reaction and in the presence of water and salt (electrolyte) sets up a battery. The aluminium being higher up the electrochemical series corrodes sacrificially and begins to eat away the lip which retains the square section o-ring. This o-ring is holding back upwards of 50bar and requires support all around the circumference. I have had a strut so badly corroded that the o-ring has been pushed out of the groove like a hernia with disastrous results.

2) The strut has a small blind hole on one side into which is hammered a rolled spring dowel. This locates into a fork shape on the chassis to locate the strut and provide a small measure of torque to resist you tightening up the sphere by hand. Other than that it's useless. Again the dowel is steel and the strut is aluminium alloy. Corrosion takes place here also. The wall thickness of the strut at this point is much thinner due to the hole of course and there does not have to be much corrosion to eat through the remaining material.

A further location of failure is where the steel plunger, which fits inside the strut, pushes on the swinging arm. It is kept fixed to the arm by the insertion of a spring clip which runs all the way through the alloy arm, through the end of the steel plunger and out through the arm at the other side. It's only spring pressure which keeps it in place at day one. However, mr corrosion sets to work with the dissimilar metals and the clip gets stuck in place. I have had this problem and had to resort to the final measure which was to strike a chisel aimed between the tapered end of the plunger and the arm until the clip breaks into three parts if your lucky. If you are unlucky the end of the plunger breaks where the hole is and the clip is left in place on the arm.

All of these are disasters enough without being unable to get your hands on spares. In tha past I have been lucky enough to get them from scrapyards but I know this won't last forever. In any case the car in the scrapyard will have all the same symptoms unless they have been replaced in the recent past.

I took the struts out of my CX the other day to recharge the spheres and luckily the clips were new and greased. I had the struts out, regassed and put back on the car within an hour. If that clip gets stuck you are looking at a whole weekend just to get the strut off the car.

Sorry, to answer your original question, I don't know where to buy new struts. I probably culdn't afford to buy them, at least from Citroen anyway.

The message here is to get them off whilst it's still possible and do a little preventative maintenance. Reassemble the struts using grease and waxoyl where appropriate and save yourself a lot of pain for the future.

Cheers

Noz