Club 80-90 Forums

jamiehamy wrote:Riiight!!


I checked the pulleys and noticed that the alternator belt on the crank pulley sat about 1.5mm above the pullet, as opposed to almost flush for the water pump pulley.
Jamie

Maybe it is riding high in that pulley because that one is a 9.5mm one and the others are not. Did you measure them?

Had similar problem on my 1.7D. Was driving me to distraction, every time I tightened the tensioner and thought it was nailed a couple of days later ssscccrrreeeeaaaccchhhh!! It was simply that the washer was bending where you tighten to set the tension. Put a much more substantial washer and a locking nut on. No problem since.


OOhhh Ive tempted fate Now!!

Haha, think I tempted fate! Half way home battery light same on. Opened the back to find a chewed belt! argh!

I think i'm on the right track tho, will need to find a proper 9.5x875 belt that is vee shaped, but without the teeth. The one I put on today must have been too flat as the edges were all boiled. I had a good close look at the crank pulley and up both sides there is an unmarked line, suggesting that the belts have either been running only on the top section, or only on the bottom section, but not the middle. So 9.5x875 - all my hopes are pinned on you! Found some one VWS website, hopefully they are okay.

Never thought a simple alternator belt could cause so much grief

Why don't you just measure the pulley sizes before you keep buying new belts? Your last description points to different sized pulley on the crankshaft to the others. I have asked several times but nothing back to say that you have checked. You will be wasting time and money if you have mismatched pulleys.

Sorry, I misread your post and thought you were referring to the belts, which I knew were 10 but because I can get them cheap, thought I'd try what options were available this weekend i.e different length and shapes. The width of the pulleys is the same, but I not yet measured the depth.

Once I get a proper 9.5 belt (ordered), then I've exhausted the belt options, alignment options and charging issues, which would leave water pump (although that's fairly new) and pulleys.

Hoping not to have to go down the pulley route, trying to get three matching pulleys sounds like a nightmare - widths, diameters, depths.

When you have the belts off have you checked for any stiffness/roughness of the water pump by turning the water pump pulley? That must be the only possible now I would have thought - you may have a duff one. There is definitely slippage occurring to get the sides of the belt cooked.

The 9.5x875 belt I ordered turned up as a 10x875.

Goodie - I've not had a chance to strip the pulleys off to properly measure up, but noticed something I'm not sure about, but the more I think bout it, seems odd.

I ran the engine for a few minutes with belt screeching. Put a finger on each pully and the waterpump one was the hottest by far.

The outer pulley (just waterpump and crank) is significantly smaller than the inner one (which goes round all three).

The two crank pulleys are identically sized. So it seems like, as you've suggested, the sizes are wrong, thus causing a mismatch in turning ratio?

The inner pulley on the waterpump will always turn faster because it's bigger, but since the corresponding pulley on the crank is not also bigger, then this must be what's causing the slippage?

I'm hoping to take everything off on Sunday if I can get time.

So may main questions are:

1) Should my standard 1.7d be running two belts (no PAs or A/C)?
2) Should the pulleys on the water pump be the same size(diameter) or is it okay they are different?
3) Should the alternator belt be going round all three pulleys (not that I can see any other way tho).

Thanks again for bearing with me.

J

Am I missing something here?
lower belt round crank and outer water pump , (adjustment via shimms) second belt round inner waterpump and on to alternator, adjustment of this belt is via alt braket.
you dont run a belt round the crank/pump and another round crank/pump AND alt..
mike

I'm beginning to wonder also.

Are you running just one belt and are there just single pulleys on crank, water pump and alternator?
My 1.6 runs with just one belt - adjusted by the alternator. Pulleys have different diameter - that just governs how fast the driven part spins.
The fact that the water pump one is significantly hotter than the others leads me to think that there is something amiss with the water pump.Hence again:
Re: Can't stop alt belt screech - 1.7d

by Oldiebut goodie » Sun Feb 12, 2012 9:11 pm
When you have the belts off have you checked for any stiffness/roughness of the water pump by turning the water pump pulley? That must be the only possible now I would have thought - you may have a duff one. There is definitely slippage occurring to get the sides of the belt cooked.

No Oldie, as I read it he has 2 pulleys on the crank which should both be the same size and 2 on the waterpump , the inner fixed one which drives the alternator and the outer split one which is driven by the outer crank, ,I read it that he has one running rounr all three and one from crank to waterpump , and as the two puilleys are correctly different sizes on the water pump then wow is that belt running round going to scream..
I am thinking that a single belt alone can be used ?? or 2 singles??

mm

jamie can you confirm and also maybe post up a picky of what you have , hard to get to but try
mm

Will try Micky.

Goodie - Not had the opportunity to get the other belt off to test the pump. Don't have the right tools at my flat. When running without the alternator belt and only the waterpump belt, there isn't so much as a squeek.

Anyways, will get some pics if I can. Will take the waterpump belt off on Sunday and try running with one belt across all three. I got the van last June and ran it for months before this issue started..strange!

Thanks guys

Forgot I had this pic already.

You can see the crank pulley in the middle - note the inside belty does sit out more than the outer.

On the right you can see the water pump pulley and the odd sizes.

The Inner belt goes up to the alternator.

metalmick8y will confirm the two belt set up - but it seems as though you have the inside belt running from the crank to the alternator whereas it should run from the inside pulley on the water pump to the alternator!
It looks as though that inside belt will try to run at two speeds by making contact with the water pump pulley on its way to the alternator.

i concur. Van came with this setup, only thing is that the belt quoted everywhere is the 875 which fits all three pulleys. Will try only that at weekend first and post back