Sphere mount bracket

[andmcit]

With many thanks to some interesting images posted by Eduardo, a new forum signee, I feel this
part of another thread he posted needs repeating in it's own specifically devoted thread to cover this
significant issue that threatens our Xm's:

Hi this are the diferences...

Citroën just sell the new one...













eduFX

A similar thread is running on the original forum too and disparate discussions all covering the
same issue may help/miss some discoveries.

I'm not 100% certain what the PC illustration versions show as these differ from a real top
cross sectioned by bandsaw? Clearly different versions in design so these show original and a
redesigned cross section where both are then superimposed over one another. An image may
speak a 1000 words but sometimes an explanation is also invaluable.

Andrew

[Dieselman]

I think the technical drawings depict Xantia strut tops but also show how the rubber is cut away in the hollow sections of the moulding.

[andmcit]

To fully understand these, what's represented by the turquoise cross section in this picture:



is this a metal stabilising insert within the rubber shown in the blue section.

Andrew

[andmcit]

Finally may show a purpose for the outer shroud that sits just below the top mount bracket;
without it the open rubber would trap a ledge of moisture that would work nasties against
the central core of the bracket.

Andrew

[xmexclusive]

I agree with Dieselman that the crossection drawings are mainly Xantia and also include some where the bolt down is shown on the top of the chassis rather than the underside.
It needs to be noted that the mode of failure initiation shown "rubber tearing" is the least common in the UK.
That the end result of all failures is the same (strut pop up) if left to run is of no real significance if you are trying to identify and remove from the design the initial failure cause.

As with all of eduFX's postings very very useful. So pleased that he found us and is so free with his rapid progress on his XM.

Andrew I think all the current threads should be let run. There is plenty of us contributing perhaps more so because of the number of different threads. Noz has already started to pull a master thread together on his site. With regard to the top shroud I think you are right about the designers intention. In practice I think that in our climate the design actually traps moisture and encourages it to condense to water and actually feeds the rust process.

John

[Dieselman]

To fully understand these, what's represented by the turquoise cross section in this picture:



is this a metal stabilising insert within the rubber shown in the blue section.

Andrew

The stripy turquoise part is just the rubber skin in the cut out sections, elsewhere it is shown as fully filled in.

As mentioned in the other thread, does anyone have some old units to use for investigation.

[andmcit]

I'm sure sphere mount failure will be discussed anywhere where there's a conversation about Xm's
and I have no problems with them everywhere and anywhere throughout the forums. All I'm saying
is why not concentrate a thread here in the general discussion area to cover this significant issue
whilst accepting there are specific sections covering electrics, diesel engines etc and specifically
one for suspension?

Whilst there's no gurantee it will remain current, with the significance of this failure, the chances
are it will be a regular thread so won't drop off the first page. There aren't stickies here are there?

Andrew

[andmcit]

Dieselman, I realise there'd be little chance of anything remaining stable even inside a solid
rubber covering but it's an odd way of showing a cross section as it appears to be a thin wall rather
than the solid thick wall of the bandsaw sectioned real one? Surely these sectioned pictures now
show the construction well enough so what would be the gain in slicing another one apart,
especially were it in good condition!?

I may add that the failure I had with one of m Xm's many years ago now was not as the result of
corrosion but a clear catastrophic shearing of the rubber's circumference. There's only speculation
that the car had been run on flat spheres as I purchased it with soft suspension.




The visible metal suspension turret collar that usually is the reason Xantiae one's go was very solid
and showing only minor surface corrosion and certainly no outward signs of an imminent failure.

Andrew

[Dieselman]

Surely these sectioned pictures now
show the construction well enough so what would be the gain in slicing another one apart,
especially were it in good condition!?



Andrew

I think I asked before the latest pictures were added by EduFX, whom I thank enormously.

What we need now are accurate measurements of the plate sizes from the sectioned one.

[andmcit]

As a start to get an idea of the measurements, this can be scaled onscreen or outputted to a dimension
where the stud is at the correct same size as the real thing:



Andrew