Theory for big end failure?

D.Slatford · Post by **D.Slatford** » 01 Oct 2005, 02:51

Something crossed my mind today, a possible reason for the unexplained big end failure on my 1.9TD Xantia on Monday.
Earlier in the year, I had a new clutch fitted. Regrettably I used 'Mr Clutch' in the absence of any other reasonable quotes nearby. The gits never told me until after I'd paid that they use recon clutches, but anyway. A week or two later I had to have a second clutch fitted, as the first shook the car to bits, clearly not right.
The replacement wasn't great either but still a replacement, and I didn't want them mucking about with my car anymore so left it. There was always a mild judder upon bringing up the clutch, and in the end I got used to it (by comparison the replacement to-the-moon-and-back car I have now feels perfect, I'd forgotten how a clutch was supposed to feel!)
Presumably, the clutch wasn't centered properly. That being so, wouldn't there be some pretty hefty stresses set up between the crank and the gearbox - and therefore, something might have to give eventually?
If there's any liklihood of this being the case I wonder if there's anything I might be able to do to prove it, then persue a claim for damages.

alan s · Post by **alan s** » 01 Oct 2005, 03:07

I wouldn't go spending any potential compensation based on that myself as in my opinion, that would have a greater chance of chopping out a main bearing than a big end if it was going to do any damage.
I haven't followed your big end failure, but that is usually caused by oil starvation so a greater possibility may be that they may have drained the engine, partially or wholly and started it dry or alternatively may have topped it up with some old claggy oil that caused the damage.
The only reason I could see for draining the sump would be if they removed the entire power train to do the job.
Another plausable theory could be that if the car was jacked up high at the front (not on a proper car hoist) and they started the engine for some reason (say to test it) they may have starved the pump of oil and caused the initial damage.
Alan S

AndersDK · Post by **AndersDK** » 01 Oct 2005, 03:14

I doubt it.
To my experience big end failures are due to either oil starvation (for any reason) - or the engine has been over-rev'ed extensively at some point in it's life.
Clearly the severe vibrations from a bad clutch will impact any direcly related components - but these are in fact designed to withstand huge vibrations.
I suspect general sloppy workmansdhip as cause for the vibrating clutch. This includes over-looking an obvious oil leak from the crank seal (which is a must replace with the clutch) leading to oil contamination rather fast after replacement.
- or as you suspect : no centering before torquing the clutch bolts.
Even bad re-assembly of the box to engine could do this - eventually leading to a bent gearbox input axle. Remeber these guys go by a fast job for money - you would go for a precious job to your own car.
It will be very hard to prove anything. You will need an indepedent 3.rd party with necessary knowledge - and pay them ...

AndersDK · Post by **AndersDK** » 01 Oct 2005, 03:21

Touché AlanS [:)]
- and pardon for this being the 2.nd time in 2 days [:I]

alan s · Post by **alan s** » 01 Oct 2005, 03:52

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by AndersDK

Touché AlanS [:)]
- and pardon for this being the 2.nd time in 2 days [:I]
<hr height="1" noshade id="quote"></blockquote id="quote">
As they say; great minds think alike..........obviously, distance has no bearing on this.[:D][:D]
Alan S [;)]

bxbodger · Post by **bxbodger** » 01 Oct 2005, 05:37

In your original posting you said that the oil had run low several times-enough to light up the warning light and you'd then topped it up again. I think the damage was done long before the clutch job!!
<blockquote id="quote">quote:<hr height="1" noshade id="quote">Over the last year in my posession it had run low on oil to the point of flashing the light a couple of times, but always filled up immediately. It did burn it all up in a thousand or so miles. Maybe that was still enough to seal its fate?
<hr height="1" noshade id="quote"></blockquote id="quote">-Yes!!!!
Like I said in the original post, I suspect that it had been run with low oil and no oil changes by a previous keeper- long before you got it!!!
I think you would be on a hiding to nothing trying to pin it on Mr Clutch!!!!

jeremy · Post by **jeremy** » 01 Oct 2005, 13:49

Engine main bearings are massively strong and have to cope with extreme unbalanced forces all the time - just look at your engine - pistons flying around on the end of con rods - yes they are in opposing pairs but they are not opposite like a Porsche (or GS or Subaru etc) engine but the last for years.
As has been pointed out its your big end that has gone not thr rear main. So thats a substantial bearing and a crank throw away form the clutch which will absorb much of the vibration.
Re-cycling of clutches is an EEC initiative in the interests of environmental friendliness and therefore big business and done under proper conditions in large factories. It certainly isn't a back shed operation and you can also rest assured that the one thing the Mr Clutch organisation doesn't like doing is work for nothing - ie warranty claims.
So if there were regular problems with the re-cycled clutches and they were any worse than new ones they would cease using them instantly.
There are may things that can affect clutch action, one of the favorites being engine mounts.
Jeremy

citronut · Post by **citronut** » 01 Oct 2005, 15:10

if the clutch was not centerd on fitting you would never get the splines on the input shaft to engage into the clutch plate splines,so the gear box then could not be re/fitted,even if they managed to get it back together,as soon as they pressed the clutch pedle down the disc is released so it would center its self,sounds to me like your repeated low oil either or as well as damaged the bearing shells or and the oil pump,in turn this will end up with crank bearing faliure
regards malcolm

D.Slatford · Post by **D.Slatford** » 01 Oct 2005, 21:43

Thanks for the replies everyone. It was just a thought that occured, shuddery clutch for months then big failure - I'll happily rule it out now. Didn't know if it was at all plausable or not. That is of course why I sometimes post here - many of you guys know far more than I

I'll just put it down to s**t that happens. It has never run out of oil - and had been well topped up for weeks previous (only reaching minimum mark a couple of times in the last year, if that alone was enough to wreck an engine I'd expect dozens of cars on the roadside each day). Ah well.

citronut · Post by **citronut** » 02 Oct 2005, 01:12

clutch judering can be caused by it being wrongly adsjusted
regards malcolm

Dave Burns · Post by **Dave Burns** » 02 Oct 2005, 15:49

Biggest contributor to big end failure next to poor maintenance is poor driving, letting the engine labour to be precise, this puts extra load on all the main rotating and reciprocating components in the block, a favourit habbit of the fairer sex usually.
What, one lady owner, no thanks.
Dave

Mosser · Post by **Mosser** » 02 Oct 2005, 16:23

Maybe the shuddery clutch was actually caused by the big end starting to fail ???????

vanguard · Post by **vanguard** » 08 Oct 2005, 00:28

Juddery clutch normally caused by badly aligned face of cover plate ie not pressing down or realising evenly due to incorrect machining or weak fingers on one side big ends dirt ,overheating rod ovality over revving !