Technical Air con/Power Steering Belt Keeps Snapping! - 1.9 JTD 8v

[mydan]

Hi there,

I am now requiring my 4th belt in under a month!

The first one went about a month ago - that was the first time it needed a new belt. I cleaned out all the junk and fitted a new one - job done. However, I noticed the tensioner had a lot of play in it (rapid left to right movement when the engine was turned on). First time around I presumed it was just the way it was supposed to be - or maybe a bend in the belt needed ironing out with a little time.

That one then snapped a week later. On inspection again, the alternator was absolutely tangled up in belt. So I had to get that off to fully clean it up - WHAT A NIGHTMARE OF A JOB. Anywhoo I can even forgive it that. So I put it back and put on a new belt and I noticed the tensioner looked more stable - as I would expect it to do. So what I presumed this time around was that the alternator was ceased after belt snap 1, and the belt was rubbing as it went around the alternator as opposed to turning it. Though it must have been turning it enough for the engine to think it was actually doing something.

Anywhoo I thought Great - anyway 4 days later and I turn the engine on and I hear the all too familiar fraying/flapping on the next belt. So I turned off the engine to prevent another tangle scenario as I don't want to have to undo engine mounts/exhaust just to get the alternator off again.

Can anyone give me an idea why it keeps nailing belts like this?

Thanks
Dan

P.S. All the pulleys that the belt goes around are smooth turning and not loose in the slightest. Hence my confusion...

 

[A3jeroen]

Check if all the pulleys are lined up properly.

gr J

 

[Deckchair5]

Yes a belt will always try to run to the high spots, almost as if it wants to self destruct and over tension itself. So I'd guess you have a pulley that is moving to an angle when running, maybe when it gets hot or under load, the belt moves to the high spot, over stretches until it rolls off or snaps

 

[A3jeroen]

I've had that on my Brava JTD. Ruined a few belts untill the mechanic found out that the alternator didn't line up. Mysteriously this happened after changing the timingbelt

gr J

 

[john55]

Yes a belt will always try to run to the high spots, almost as if it wants to self destruct and over tension itself. So I'd guess you have a pulley that is moving to an angle when running, maybe when it gets hot or under load, the belt moves to the high spot, over stretches until it rolls off or snaps

Just change the tensioner on my JTD last week and the old one was very worn, not the bearing gone but the plastic surface that touches the belt worn to a strange shape. Lots of bumps and grooves in what used to be a flat surface.