Flow divider XM / Xantia

[ekjdm14]

Pictures!!

yes please!

I meant: Pictures of your Xantia please!! haha I am an enthusiast of early Xantias!

All in good time though. Chat soon!

As did I... And very nice the pics are too.

[aerodynamica]

Looks good - what sort of kilometerage has it reached?

[aerodynamica]

OK! I hope this info isn't too late for you but I have had a look at my spare FDV unit that came off my previous Xantia 1.9 TD SX 1993. It is an FDV that had no modification or any service work because I swapped the FDV for one I had serviced and shimmed etc.

Anyway I measured the dimension of the screw/bolt to the outer surface of the FDV body (it was slightly recessed unlike what I said last week that it was level to the surface) The dimension is approximately 0.9mm. So, it is almose 1.0mm recessed on this FDV. I marked the position before loosening, I removed the lockring and counted the number of full turns until it removed (5 full turns). I measured the screw thread pitch to see what the distance between the threads is (measured at 1.27 on my caliper but obviously there's error as it is a manual measurement so it is probably 1.25mm). I measured the spring as well.

Photos:
1. FDV ready to investigate
20170416_191539 by Graeme McNulty, on Flickr

2. You can see the screw is recessed from the surface
20170416_191608 by Graeme McNulty, on Flickr

3. Marked before loosening!
20170416_191853 by Graeme McNulty, on Flickr

4. Measured dimension of the recess
20170416_191949 by Graeme McNulty, on Flickr

5. Lock ring removed, mark still visible.
20170416_192240 by Graeme McNulty, on Flickr

6. Screw thread pitch measured visually - about 1.25mm
20170416_192618 by Graeme McNulty, on Flickr

7. Internal spring measured - about 17.2mm
20170416_192940 by Graeme McNulty, on Flickr

8. Refitting screw to 5 full turns from first thread - ends in the same position so it is considered an accurate record of the dimension.
20170416_193112 by Graeme McNulty, on Flickr

9. Screw and lock ring tightened and in the same position
20170416_193315 by Graeme McNulty, on Flickr

I'd be tempted to reset the new position a little bit tighter than the start to compensate for the spring losing tension over 23 years. But it would be an educated guess as to how much more it would need, say, 25% ??

10. Final picture, FDV returned to its original state..
20170416_193320 by Graeme McNulty, on Flickr

So these are not exact measurements and it is possible your own FDV would differ in some way.. I don't know if this one differs from the FDV that is fitted in my Xantia because I didn't touch this screw on the FDV a few months ago, I only added a little 1.5mm shim to the first big spring of T1 valve like in the XM forum thread a few years back.

I hope this helps anyway since you lost the original place of the screw. If I was you I would wind the screw in to about 1.0mm less than the outer FDV surface to get the best likely result.