Worn Poly V Pulley

The alternator belt on my Citroen Xsara diesel broke at the weekend and I got it replaced at the garage yesterday. However this was not a simple (or cheap!!) replacement. The belt was still basically in one piece but had come off the poly V pulley on the crankshaft and jammed itself between the belt tensioner and the camshaft cover, badly bending the tensioner and breaking the camshaft cover.
However the surpise was that there were no grooves left on the crankshaft pulley. The pulley ressembled a flat belt pulley with only an occasional slight impression of where the bottom of a groove had been. All the other driven pulleys were OK and what remained of the old belt also still looked like a poly V belt. The garage people had never seen anything like it and we are left wondering how the grooves had, effectively, been ground off the pulley.
The car is almost exactly five years old with 120,000 on the clock and the belt was the original as far as we can tell.
Jim.

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More likely the grooves were never there ? It is a Citroen after all... I've had 3 in the past (2 * BX + 1 * Xantia) and although they had some definite advantages (esp the better of the 2 BXs) I eventually swore off them on grounds of unreliability + servicing costs.

Boo wrote:
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I agree. It takes a long time and many belts to wear out pulleys. I have a pair of cast iron V-belt pulleys which were in use for several hours daily for 50+ years, and the wear to the grooves is only just noticeable. I also think (but am not completely certain) that I've seen poly-V belts running on pulleys without grooves in washing machines. The grooves are most important on small diameter pulleys.
Best wishes,
Chris

uk.rec.models.engineering wrote:
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Dunno, those continentals have funny ideas about belts, etc. I once bought a Holzer vertical panel saw at a silly price. Took me about a fortnight to rewire and rebuild the control box so that it worked (two dimensional X,Y motion). Lasted about 2 years. The 5hp saw moved vertically on a carriage positioned by ~3/32" stranded steel wire over aluminium pulleys. Guess what?? The wire sawed thro' the pulleys. I did get it dismantled with great difficulty, gave up trying to get all the bits back together.
Regards,
David P.

On Wed, 03 Sep 2008 21:27:47 +0100, Boo
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I've had exactly the same - 2 * BX + 1* Xantia, and conversely my experience has been just the opposite. The Citroens have probably been some of the most reliable cars I've ever owned and servicing costs very really very low, although in fairness I did these myself.
My 1st BX (petrol) was written off by the RAC. They were towing it without the steering lock on after a belt broke and they didn't have one to fit, and within less than 1/2 a mile on a windy road they collected 3 cars and a lorry as the BX swung across to the other side. Got me a spot in the national press and an invitation (declined) from Johnny Vaughn to appear on the Big Breakfast (there were odd circumstances surrounding the incident..)
The 2nd BX (petrol) did over 40,000 miles one year, and went to France over the Route Napoleon several times laden with family and luggage without complaint.
The Xantia (diesel) put on 70,000 miles in 3 years with just oil and filter changes, still doing the annual trip over the french alps and a couple of F1 pilgrimages to Monaco. I did have one breakdown where the plastic clip holding the cable to the clutch pedal broke, but luckily this happened just a mile from home.
The hydraulics that seem to put people off are really a piece of pi** to work on, and I wote a piece about servicing the suspension cylinders for the BX forum about 8-9 years ago. I used to replace the spheres once a year as part of an annual service, using pattern ones from Andyspares in Reading for around £12 each, as opposed to £80 each from citroen. It was less than 30 minutes work and £50 cost to maintain a superb level of comfort.
Maybe I was just lucky with mine.
Peter

On Thu, 04 Sep 2008 09:29:56 +0100, Peter Neill
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Totally agreed
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Exactly my experience with the Xantia (even to the mile from home!).Fitting that clip was a right bu??er! Always carried a spare from then on and left it in the car when I traded it in at 138000 miles.
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Likewise.
That makes two of us
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Now have a C5 1600cc HP diesel. Got 72mpg between Cheltenham and Folkstone on recent trip to France. By the time we got home 1600 miles at 60mpg including 80 on some Motorways over there.
Main problem is depreciation but overall I am very pleased with my Citroen purchases. Not likely to go to the new model C5 as the ashtray is miniscule!

On Thu, 04 Sep 2008 11:55:00 +0100, Richard Edwards
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Nice to know there is another 'social leper' on the NG <vbg> I gave up on ashtrays years ago and just use the window now.
Peter

uk.rec.models.engineering wrote:
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I gave up over 40 years ago, we'd taken the hood off the TR to enjoy the sunshine, no 70 mph limit then, and the bloody girl friend opened the ash tray...
Please be careful, some of those buggers from the anti-everything stazi may be watching you. I've got a piece of ali tube just behind the gear lever, over what would be the shaft tunnel on a rear wheel drive. Stick a tun dish in the top, makes an excellent infinite capacity ash tray. Serves for a few other purposes, too.
Regards,
David P,

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Tee hee. Could be interesting to use while on the move, or is there a covert boast here?
Cliff Coggin.

uk.rec.models.engineering wrote:
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You may be confusing my ash tray with a gadget that I'm told is sometimes fitted for the convenience of female drivers.
Regards,
David P.

On or around Thu, 04 Sep 2008 09:29:56 +0100, Peter Neill
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The problems with the BX hydraulics were the 4 front-to-back pipes, in steel, with inadequate protection from the crud which landed on them near the portside rear wheel.
Garages were wont to want $sillymoney to change 'em.

<Jim Guthrie> wrote in message
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Are you sure the actual V part of the pulley was still there?
The pulley is a torsional vibration damper, and is made up of a steel inner section, rubber bonded to the outer section with the V grooves. It's not unknown for the rubber bonding to break up, outer section makes a break for freedom, and the belt goes where it shouldn't.
You were lucky that it only cost you a pulley, tensioner and belt. It isn't unknown for engines to be destroyed due to alternator belt/tensioner/crank pulley failure.

On Thu, 4 Sep 2008 12:15:34 +0100, "moray"
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I saw the old pulley and there was no sign of anything ressembling rubber bonding - only a flat(ish) pollished steel surface. So your explanation would explain what has happened. I haven't seen the replacement pulley, since it is well hidden when installed, to see what the working version is supposed to look like. I had to drive it for a few miles to get it home, then get it back to the garage the next day, so the polished surface may have been caused by some of the debris rubbing on what remained of the pulley
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The cam belt cover was smashed and one of the cam belt pulleys showed signs of rubbing on one of its faces, but the cam belt itself was checked out and found to be OK. The garage reckon I was luckjy to still have a working engine.
Jim.