Russ's 2.1 SED Auto now in Mandarin

[xmexclusive]

Hi Russ

I suspect that it was all very carefully considered but the available strut head space was already fixed by the graphic design.
In the case of the XM body shell it was Citroens first production space frame design totally by computer.
Even the glass panel strengths were included in the structure analysis calculations.
We see the results of missing the value of the worst stress case with XM lifting points that cannot take significant lateral load.
Finding all those worst cases in a theoretical study is a designers nightmare.
Computer programmes at the time were not known for ease of use.

It was claimed that Citroen fatigue loaded all XM critical components in laboratory tests.
These progressing at a number of times the worst expected XM service life.
The test mules were also circling their test track well before XM launch so were way up on mileage to service cars.
I suspect that the weakness of the early strut head design first showed up during these tests.
I doubt that there were that many service failures as there was not a widespread Citroen operation to replace the components.
Just a set of component redesigns introduced less than 3 years from XM launch.
Commercial pressures may have dictated actions of course.
Sales were down on expectations, wiring problems etc had given the press lots of negative scope.
Problems with the quality suspension, a major selling feature, were the last thing Citroen needed.

I will see if I can find some photos of the rubber contact area and some of the other items mentioned in the above posts.

John

[White Exec]

Here
http://www.ebay.ie/itm/AUTO-PARTS-PUMP- ... SwQYZWw0To
the C5 baseplate looks ? taller than XM. Doesn't look circular, either.
>>>> Be sure to see detail photos further down the ad as well.

Trying to find other pix or diags for C5/C6.

Just found an interesting photo of popped C6 strut:
http://c6owners.org/plugins/forum/forum ... ?7957.post
There is mention in the thread's early posts of a ?retaining? circlip.
It also looks as if the C6 strut-top was modified by Citroen more than once, but not clear whether this was because of leaks or for strength reasons.
[C6 site allows Searches without registering btw]

[russ92xmsed]

It's no wonder Citroen are going to their new set up, it's much less hassle when it comes to designing strut tops that don't fail! Interesting that the C5 and C6 are three studs.

The C5 is another that I haven't heard of any failures. That's the mk1 version I am referring to. Shame they don't fit an XM really.

[xmexclusive]

I have a few C5 ones as I tried to design a spacer to fit them to an XM.
The C5 strut rod and later thick XM strut rod are virtually identical.
Close enough for the "O" rings to seal.
Just not enough space to fit them under the bonnet.
The sphere position clashes with chassis top member.
Though about rotating them a bit.
That is when I realised strut head rubbers are torsionally varied so they cannot be rotated.

John

[White Exec]

John,
The C5's 'steel angular plate reinforcement built into the rubber' - Any details on this?

[White Exec]

The C5 is another that I haven't heard of any failures.

I have posted a question about this on FCF, which is well populated with C5's.
The C5 was launched in 2000, so has been around long enough for failure to manifest itself.

[russ92xmsed]

Little update. The XM went in on Monday to Tony Westons to have its spheres replaced. I ordered four new IFHS from AEP, and had my proper Citroen spheres that Will kindly tested at the Chevrons regassed and put on. They were from the grey car. The spheres were last done about 4 years ago and the ride has been a tad brittle of late.
Whilst it isn't incredibly floaty, it is much better and is improving the more I drive it. But there is a distinct difference between sport and normal modes. I think I am being ultra sensitive with ride quality at the moment, as I am convinced the C5 needs new spheres as the ride is quite hard now.

Also a while ago I discovered a hole on the underside of the sill under the wing on the passenger side. Usual spot and story. Trapped dirt causing rot. Anyway, I have left it long enough... It was time to get it cut out and patched. The jacking point on that side was mangled by a tyre fitter, when Rob owned it. It had been welded, so was okay, but not pretty.
Hole is now patched and the sill strengthened in three places. The wing has new metal added to the bottom which had rusted away.
The jacking point has also been pulled down a bit. Really in truth it needs all cutting out and completely rebuilding, but I have had enough of spending money on it this year, so the current repair will do for now. It looks so much better regardless and the worry of knowing rot was there, is now thankfully gone.

Next job, oil and filter change, and pump the sills full of fresh oil to help keep the dreaded ferrous oxide at bay.

[Dieselman]

But there is a distinct difference between sport and normal modes. I think I am being ultra sensitive with ride quality at the moment,

That is correct and an astute driver will notice it.

H2 cars don't exhibit this to the same extent as the corenr spheres are both larger and have more relaxed damping...but roll more when cornering...

[White Exec]

I ordered four new IFHS from AEP . . . Whilst it isn't incredibly floaty, it is much better and is improving the more I drive it.

Russ, did you also replace or regas the centre spheres?

[russ92xmsed]

Yes I did Chris. All have been changed. It is softer, no doubt about it. Put it this way, it glided over a speed bump beautifully.
I think there might be a little air ingress at the pump feed pipe on the tank. I shall be taking a look at the weekend.

Also I think a change of tyres would probably see the greatest change in ride. But that's not happening yet!