strut mounting, strut monting

[noz]

If those dimples are indeed expanded into an annular channel then it is conceivable that Part 1 in Paul's image can be made to rotate with respect to part 5. It would be a matter of gripping part 1 with some sort of clamp, without touching the rubber that is, and rotating part 5.

It may reveal more about this option if someone would take a hacksaw or bandsaw to one right down the middle. Any volunteers?

cheers

noz

[xmexclusive]

From a quick look this evening I think side swapping is a dead duck.
The strut is not vertical but inclined a few degrees back towards the windscreen.
So turning the baseplate through 180 degrees will point the strut in the wrong direction.
Even if you could fit it all together at best the strut would not work properly and bind when it tried to move.

John

[minijet]

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Hi John,

I'm not talking about turning the base plate at all.
My intention was to leave everything exactly as it is, but just turn the top part (5).

Place two strut tops side by side and compare them. You'll see that they're identical except that the top (hydraulic parts) are facing in different directions, the individual components are exactly the same both sides.

I'll get my two spare strut tops out and take some pics tomorrow to try to demonstrate what I mean.



Noz,

I agree with you about slicing one down the middle to see what it's like inside.
Unfortunately, it's way beyond my capabilities.

Paul

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This post has been edited by minijet on September 15, 2010 05:01 pm

[xmexclusive]

Hi Paul

I think that the head centreline is inclined from the vertical in both directions relative to the baseplate.
If so then even with a turned strut head it will not line up in at least one direction.
Have looked up the XM strut rake back (castor angle) this is 2.5 degrees positive.
The camber is less at 0 degrees 15 minutes for hydractive.

John

This post has been edited by xmexclusive on September 14, 2010 09:46 am

[kenhall1202]

No need to slice one down the middle. The attached Citroen picture shows a sectional view of the strut top and is much the same as Paul's excellent sketch except it does show the interference fit between the inner and outer parts (you may have to blow up the jpg to see it).

I don't see any problem with the concept of rotating the strut head but it would require considerable force and you may end up losing the tight fit between the two parts.

Regarding castor and camber angles surely these are mainly determined by the geometry and set up of the hub and lower suspension arm and the top strut fixing merely follows suit, allowed by the flexible rubber, as the geometry alters with front wheel direction.

Many other cars use this so called Macpherson strut type suspension (eg Peugeot 605) and I believe that the strut top incorporates some sort of bearing to allow the strut outer and coil spring to rotate with steering movement. It makes me wonder if there is any scope for re-engineering the XM strut top to use a self aligning bearing in place of the imperfect rubber??

Ken

This post has been edited by kenhall1202 on September 16, 2010 10:56 am

[xmexclusive]

Sorry for the red herrings.
Have now double checked on an actual car in daylight.
Am satisfied that the chassis mount for the strut head is angled to a plane that is at right angles to the strut rod centre line.
So agree that rotation of the centre does not alter the steering geometry.
Will be away tomorrow for a few days to pick up an XM and tour the borders.
Will be interested to see how this has developed when I get back.
I have a new XM strut head that I and keeping in case we need to measure rubber resiliance in various directions when designing for remanufacture.

John

This post has been edited by xmexclusive on September 14, 2010 02:14 pm

[minijet]

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QUOTE (xmexclusive @ September 14, 2010 01:46 pm) 

Will be interested to see how this has developed when I get back.

Hi John,

not much, the way things are going, we're a bit stalled at the moment

Have fun in Scotland

Paul

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[minijet]

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Great picture Ken, that's just what we need.

I've enlarged the area that we're interested in and highlighted the part that we seem to be having the problem with. The bit where the inner cylinder (1) is pressed into the recess in the top part (5).



I hadn't realised the importance of this connection before, but I can now see that those (ten) small dimples are actually taking the weight of the car (well, one corner of it at least).



I still think it may be possible to turn the top part to convert a N/S strut top to a O/S one, but that would only be a short term solution.
And it may (as previously mentioned) damage the two parts in the process.

Paul

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[minijet]

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I've been wondering if the inner cylinder (1) could be crushed, to remove it from the top section (5).
This would of course mean another part would have to be manufactured, but we would at least be left with the usable top hydraulic part (5), which would I assume be expensive to manufacture.
I'm assuming that the inner cylinder (1) would be a relatively cheap part to manufacture.

One more thing.
I haven't forgotten Noz's concerns about the legal implications of fitting none standard parts.
It's just that I don't want to think about that at the moment
One thing at a time eh

I wonder what DS, CX, SM, etc, owners do about replacing their strut tops?
Does somebody manufacture new ones?
Come to think of it, what about all those other vintage cars that parts are no longer available for?

Paul

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[kenhall1202]

QUOTE (minijet @ September 14, 2010 06:23 pm) 

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I wonder what DS, CX, SM, etc, owners do about replacing their strut tops?


Paul

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Simple - they don't have to bother because the cars used the more elegant double wishbone arrangement or similar - hence no strut tops.

Ken

[kenhall1202]

Here is a (poor) very preliminary sketch of how a sound strut top with failed rubber might be modified to incorporate a self aligning ball bearing or spherical roller bearing. A standard bearing size of 65x120x31 would appear to suit the space available.

Please note that I don't claim to be a qualified mechanical design engineer and so this is only speculation and for discussion at this stage. I could well be talking bo----ks - it wouldn't be the first time!! Obviously any final design would need to be checked and approved formally.

If such a design is feasible then I think it would be very durable providing that the bearing lubrication can be maintained and water / dirt kept out. It wouldn't be a cheap modification because of the expensive large bearing and fabrication cost but could cost a good deal less than the £422 asked by Citroen.

Ken

[noz]

I have placed a call to Lemforder to investigate either a direct supply from stock or a limited re-manufacturing run. I currently await their response.

Cheers

noz

[noz]

I have spoken at length with Lemforder but they are unable to track down the part. I have tried looking through their on line catalogue including the Xantia section with no luck. AEP still have Xantia strut tops on sale at £130. Therefore, if they were Lemforder parts then you'd expect to see them on the Lemforder on-line catalogue but they were not there.

I took a couple of rotten spare strut tops I have and cleaned them up. I specifically went looking for the little Lemforder symbol and any part numbers. On the base of the rim on the lower part there is indeed a number. On one it is 9505044 and the other is 9505044 5 with a slight gap between the trailing 5 and the preceding 4. I suspect they are actually the same number since the lower half of the strut top is not sided as discussed previously.

However, I have also looked very closely with a magnifying glass at the little triangle. Instead of an owl I have the numeral 5 inside the triangle on both strut tops. I'm beginning to think this is not a Lemforder part at all. It may explain why Lemforder can't find it.

Other numbers which appear on the upper cast steel section are 050407, 320 94 and 39. I've googled all the numbers but turned up nothing. There's a picture or a symbol on the small vertical surface next to where the pipe restraint is bolted. The thick black paint obscures the picture so I'll use some paint stripper or something later to remove it.

One step forward...two steps back.

noz

[kenhall1202]

I have looked more closely at my strut top and you are indeed right Noz the triangle has a letter 5 in it and not the Lemforder owl OOPS! My sincere apologies for the earlier misleading information. In my defence I would say that Lemforder have made Citroen parts in the past and I recall fitting their replacement steering rack end joints/flexibles to a former CX with DIRAVI steering.

The strut top in question was removed from my '96 2.1TD driver's side recently as I was concerned to see the sphere rubbing against the lip of the scuttle. Fitting a 'new' secondhand top has restored the clearance between them.

There is a number cast in the rubber underside of the removed strut top,
96 285 284 80, plus a DOM indicator for 1996 plus the triangle/5. The top casting has three separate numbers on it: 050407, 179 95 and 36 (on sphere neck connection).

My 2.1TD uses the later larger diameter (25MM?) strut rods with the corresponding enlarged taper in the strut top and the current Citroen part numbers are 527188 (Left) and 527189 (Right) which obviously bear no relation to the above numbers.The 10 digit number looks like one of the older type Citroen part numbers which don't appear to be used very much now.

Ken

[minijet]

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QUOTE (noz @ September 15, 2010 03:17 pm) 

AEP still have Xantia strut tops on sale at £130.

noz

!!

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This post has been edited by minijet on September 16, 2010 09:39 am