squealing!

[Stephen Edwin]

Derek's answer sounds pragmatically practical. Can those belts be obtained in the future so far as is known? If so, that is a god way forward?

For a fundamental cure, as it seems the alternator pulleys may be the issue, is it feasible to change those pulleys?

[Clifford Pope]

I still would have thought you could pinpoint the source of the squeal by elimination.
You suspect the inner belt. What happens if you try it with only the outer belt? Squeal gone, or still there?
Try just an inner belt. Does it make a difference which belt - 10 mm or 9.5 ?
Try running some oil into the hole in the water pump shaft housing.
Try a squirt of WD40 or nylon lubricant on the alternator pulley while running - does it eliminate or change the squeal?
Do you have a spare alternator you can try? It doesn't have to be a working one, just have a different pulley that spins freely.

Look very carefully at the alignment of the pulleys. Put a straight edge across two of them and squint along from the 3rd - is any pulley either turned at a slight angle (eg soggy alternator mounting rubber) or not in alignment (eg water pump pulley needs packing out, or alternator mountings need shims)

[Derek UK]

Not wanting to leave any stone unturned, although it could get boring, you could try a pairing of the 9.5 and 10mm belts. Change them over as a cross check. Sometimes it's visibly noticeable if one belt is "tighter" than the other by the way they move around, especially when you blip the throttle.They can still work fine like this with no noise or slippage.

[Paul240480]

Okay, I intended to wait until the new 10mm belts arrived. But I needed to see for sure what the snag was & follow the advice given:

So the Conti's (the old 10mm) are back on:


Result is that both inner and outer belts are tight, more importantly no 'squealing' all is nice and quiet once again

The 9.5mm's in situ just before removal - you can see how much 'deeper' than the 10's they sit:


And here, you can make out the (inner) one that was slipping, almost no teeth left in one place!


I guess the pulleys have either worn wider with age or with me using 10mm belts for the last 4 or so years.... no idea what the current alternater had fitted as its a used spare.

Thanks all.

[Derek UK]

Is it me or does your first pic with the Conti's fitted show the alternator quite a bit out of line?
After writing the above I went out and had a look at mine.I have a set of fresh looking Volvo 9.5 toothed belts. Depth a bit below the Conti's but a lot higher than your Volvo 9.5's. I think you have found your problem by showing the belt with worn down teeth and new 9.5's should cure the squeal. However, if the alternator IS out of line then the problem may come come back fairly soon. A previous thread relating to this was about adjustment and that probably started the unusual wear. Not been there, only had mine 6 weeks, but does the alternator or its mount have rubber isolator bushes? I've read that the alternator does have a prone to break earthing strap so I think it may have. If one/both/all of these bushes have collapsed or washers have been added to beef up the mount, adjustment will tend to pull it out of line. Effects may vary and maybe with a 2 belt system the one nearest the front will give the most problems as that will just a bit slacker.

[Paul240480]

I had a good look today, it doesn't look out of kilter with the 'naked eye ' .... Perhaps it was the angle from which I took the photo?

Anyhow, have collected 2 steres of wood today with my trailer, boot full of logs too and still no squeal
Thanks.