Technical Doblo a/c fanbelt details

[ConradM]

Hi newbie here?
On my 03 plate Doblo ELX 1.9 jtd, with aircon, I currently have a chirping/rattling from the drive belt side esp when engine-braking. So have ordered new camshaft pulley, timing belt kit and aux belt (in for a penny etc).
The aux belt that's already on there is 5pk1815 but it's not filling the pulley grooves. The options online suggest 6pk1815 should be the size. If the difference between 5pk and 6pk is an extra rib on the drive side of the belt, and if the belt length is the same, does using the thinner one matter? Will the thinner one load bearings and exacerbate wear?
Ta
Conrad

 

[portland_bill]

Check the alternator pulley. Quite likely to be an overrun pulley with a freewheel in it. These can give up, and a chirping noise is what I might expect. Any doubt, change it before it destroys the alternator.
Check the Multipla threads. Several have experienced cracked alternators due to seizing pulleys.

 

[ConradM]

Thanks, that was fast!
Sounds like a timely warning
How do I get the alternator pulley off?
The car last had timing belt done 60k and 8 years ago so I planned to do the lot anyway, would definitely want to get all the foreseeable problems on the way
Ta
Conrad

 

[portland_bill]

How do I get the alternator pulley off?

The simple answer is undo the nut and pull it off.
Reality will not be that simple.
To stop the shaft rotating needs the pulley to be held, so a bench vice is probably the easiest. So the alternator has to come off. Have a good look at it before starting work, some come out easily, others seem to be built into the car.

Start by disconnecting the battery, then the cables from the back of the alternator, taking careful note of which one fits where.
Release the belt tension and remove it.
Remove the alternator mounting bolts and remove the alternator.
(So much easier to write this than to do it)
Alternator may come out upwards, or downwards, hence the reason for a good look before it is dangling in your hand.

Once out, hold that pulley. The old belt wrapped around it can help avoid damage. Undo the nut. Tight.
Now the pulley should come off the shaft. Now there might be a lot of heaving, and swearing. Might need a puller. If levering behind it, take care, the alternator casing is not particularly strong.

Before doing this, take some measurements of the pulley. Diameter, number of grooves, length, offset from shaft end or alternator body.
Then search online for a replacement. Prices vary by quite a lot. Descriptions are also variable, so take care that you select the right one. Although, as far as I've seen so far, there are not too many choices.

 

[ConradM]

Hi
Update. The cam pully was offset wrong width so was out of line with the other fittings - a previous owner had got around it with a thinner belt. All the chirping was cos the grooves were still a tad out. With new stuff all was well. Ta for the advice.��