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Discussion Starter · #1 ·
Ive bought this up in the past with no definitive answer.

My alternator belt makes an annoying slapping/squealing noise on tick over and when im driving. It tends to do it more when its wet but does it even in the dry, i spray belt dressing on it which helps but only for a short amount of time, then it comes back.

Anyway, i looked at the belt this morning and it almost looks as if it has shifted to one side, it has also stripped one of the 6 grooves off. The belt is going to need to be replaced either way, but do i go for the standard length belt or go for one a couple mm shorter so its pulled tight...

What would be causing it to do this? Its started to drive me insane! Its on a 2.5tdi AJT

Thanks
 

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I had a similar issue when I first did my TDI conversion. It turned out that the pulley on the alternator was smaller than the belt causing one of the ribs to shear off (the previous owner of the Golf I had taken it from had fitted a Polo alternator).

Replaced the alternator and haven't had the problem since (yet!).
 

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Discussion Starter · #5 ·
just checked the pas pulley and it seems like its round the right way, ive never taken it off so i cant imagine itll be that same goes for the alternator pulley.

Looking online it could be a number of things, but i dont want to start replacing stuff for the sake of it. I have a spare aux belt tensioner, might try replacing that first as the bearings inside go and could cause the noise im getting...
 

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just checked the pas pulley and it seems like its round the right way
Looks identical from either side but offsets the belt by about 5mm & causes the exact symptoms you describe ~ well worth checking as it is not obvious & can take ages before it becomes a problem :ILU:
 

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Discussion Starter · #7 · (Edited)
hmmm... ill double check it later this evening and let you know how i get on. I did check at lunch time but as you say, if its not that obvious.

I should point out that this isn't the first time its done it, i had the complete belt come off through the same thing, luckily it didnt catch the cambelt and it has taken a while for it to get to this stage, so maybe it has been tampered with before i bought the van about 1 1/2 years ago.

As i am going to buy a new belt, whats the shortest i can go before it doesnt fit? I believe they are 1753mm for the automatic tensioner or 1763 for manual tensioner. That comes to my next question, how do i know if its manual or automatic?
 

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As i am going to buy a new belt, whats the shortest i can go before it doesnt fit? I believe they are 1753mm for the automatic tensioner or 1763 for manual tensioner. That comes to my next question, how do i know if its manual or automatic?
I'd buy the correct belt from the main dealer ~ your AJT should have a spring loaded tensioner (automatic) :ILU:
 

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Discussion Starter · #9 ·
I'd buy the correct belt from the main dealer ~ your AJT should have a spring loaded tensioner (automatic) :ILU:
Good news, I replaced the belt with a gates belt, i opted for a couple mm shorter and the noise seems to have disappeared (Fingers crossed) and whilst i was at it, greased up any bearings i could see...

Not so good news, i found the cause of the belt tearing, the big bottom pulley that is bolted to the crank, the outside lip has snapped off somehow and it has left sharp edges, i have a spare and bought a new crank bolt from vw ages ago, so chances are its going to happen again but needed my van for work. Whats the complications of removing the bottom pulley? Also found the pulley on the alternator seems abit buckled when i spin it, this could be causing the belt to wobble and catch the sharp edges...
 

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Just for clarification. The pulley on the power steering pump should be mounted so that you can see the 4 Audi rings stamped into the side.
Complications regards removing that dampner pulley are that you could inadvertently remove the crank pulley attached to it and therefore remove your timing belt. You need to overcome the huge torque of the big bolt and then remove the smaller bolts and keep that rear sprocket in situ.
 

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Discussion Starter · #11 ·
Just for clarification. The pulley on the power steering pump should be mounted so that you can see the 4 Audi rings stamped into the side.
Complications regards removing that dampner pulley are that you could inadvertently remove the crank pulley attached to it and therefore remove your timing belt. You need to overcome the huge torque of the big bolt and then remove the smaller bolts and keep that rear sprocket in situ.
Thanks for your reply T:

I took the PAS pulley off and if i were to turn it around, it would stick to far out so put it back on the same orientation i took it off. I confirmed this but looking at a spare pump i have that is still bolted to the mount...
 

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The damper pulley isnt a big job, you need a fly wheel hold tool (or the proper vw tool for the job) which can be found for other makes of vehicle. And you need a 200Nm torque wrench. And some muscles
 
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