405 Mi16 clutch woes!

[halkyardo]

Hi all! New to the forum but you might have seen parts of my tales of woe on Facebook groups, Aussiefrogs, etc. Long story short, I have one of the handful of 405 Mi16s that were sold in the US. It's a relatively early-production (November 1988) car, 1.9 cat engine (XU9J4Z, DFW code), BE1 transmission. As far as the mechanicals go it's no different from a cat-equipped LHD European-market car.

Anyway, the car has had a slight but noticeable clutch drag the whole time I've had it. Recently, it got much worse, and I noticed that the bottom bellhousing bolt was missing! Replaced that, the drag went back to normal levels, but soon after that, the clutch started slipping. So, out with the transmission (which ended up needing a rebuild, a whole saga in its own right), and in with a new Valeo clutch, pressure plate, and release bearing. Got it all back together last weekend, and now the clutch won't fully disengage! I can start it in gear with my foot on the clutch, but I'm completely unable to get any gears from neutral, no matter how long I wait for it to spin down.

I've fiddled with the cable adjustment about as much as is physically possible, with no luck. I seem to get a reasonable amount of movement at the clutch arm, so unless I'm mistaken, the problems' got to be inside the bellhousing. I'm starting to wonder if I put the clutch disc in backwards, but surely that would make horrible noises from the disc hub contacting the flywheel, wouldn't it? I'm resigned to taking it all apart again and inspecting it, but is there anything else I should check while I'm in there? I'm starting to run out of ideas.

The other related concern I have is that the machine shop who resurfaced my flywheel only took material off the friction surface, and didn't touch the pressure plate mounting points. Since this is a stepped flywheel, is this going to cause problems for me? The Haynes manual doesn't say anything about the step height, but surely there's a spec for it out there somewhere. If anyone has access to the factory manuals, or has a known-good flywheel that they can measure, I'd really appreciate knowing the size of the step between the pressure plate mounting points and the friction surface, so I can check how much material I've lost and hopefully get it put right.

[Stickyfinger]

Early Mi16 cars are rare beasts these days !....I cannot help much but here are the parts diagrams/part numbers for the 405....pick/click your engine etc

https://www.catcar.info/peugeot/?lang=e ... 1GQ1QwMDAx

PUG1OFF may be able to assist with the details of the flywheel sizes etc.....
https://www.peugeot-tuning-parts.co.uk/ ... b8935d46f8

[halkyardo]

Thanks Alasdair! It's a challenge keeping it on the road but it's worth it for the driving experience!

As an aside, many years ago when I lived in New Zealand, I had a very early 'sinker' Xantia. I regret getting rid of it to this day!

Anyway, got it all torn down again this morning. No obvious smoking gun, unfortunately, I had the disc installed the right way around, and it moves smoothly on the input shaft splines. However, I did notice odd shiny areas on the friction material that weren't there before, almost like high spots that are getting polished by flywheel contact when it's supposed to be released. Manufacturing defect? Or just slap it back together and do some aggressive takeoffs to try and wear them down?

[Stickyfinger]

NP, is it the flywheel or the clutch causing that ?.... I would get them checked for "true flat" before putting them together myself.
To my eyes that is a damaged clutch plate....but what did it ?...are those cuts in the friction material ?... I would not be happy fitting that one.

[PaulC5]

If you still have the old clutch plate compare its thickness to the new one, if too thick it might not be able to disengage fully. Also compare the clutch cover and bearing. I once fit a cheap clutch to a car and that barely disengaged until the clutch pedal was almost down to the floor so swapped it for a dearer one and that was ok.

[halkyardo]

I don't see any cuts in the friction material - just slight high spots that appear to have been polished down slightly. The new disc measured around 8mm thick, while the one I took out was a shade over 6 - the old one was almost down to the rivets, so I'd expect it to have lost some material there.

I think I've got to the bottom of the issue though, my new clutch cover appears to be defective! After taking it apart again, seeing nothing obviously wrong, putting it back together, and STILL having the same problem, I stuck a borescope through the starter opening while a helper put their foot on the clutch. There are three slots in the side of the cover where you can see down to the pressure plate and flywheel.

Through two of the three slots, I got a nice positive release, with visible clearance between the flywheel and pressure plate, much greater than any of the high spots I was worried about:


But then on the third slot (and of course it was the last one I checked), it barely moved at all, and the springy core of the clutch disc took up all the motion, leaving it still in contact:


With the new clutch cover removed, I do see that one of the leaf springs around the edge doesn't quite look like the others - the leaves have a little bit of a gap between them and one of them feels slightly loose, while the leaves on the other springs sit tightly against each other and can't be moved at all. I fitted the old one back up and got even, visible clearance all the way around, so I guess I'm just using that for now! Beware bad-out-of-the-box new parts!

[Stickyfinger]

After market, indeed they do need checking.

The "cuts" I was looking at.

[halkyardo]

I definitely noticed the spots you mentioned, but I don't think they're cuts - I thought they were fibres winding through the friction material. Might be mistaken on that, but at this point I unfortunately have to get the car mobile somehow (since it's blocking in another car that I need to work on!), so I'm going to try my luck with it. Fingers crossed!