The belt should have no more than 1in of slack in it... Interesting that if you turn the crank that the belt slips on the alt pulley... can you pull the belt off and see how freely the alt spins?
You tighten the belt by changing the number of shims between the two pulley halves. The pulley has a V shaped notch, so fewer shims between the pulley halves causes the belt to run further out, and hence is tighter. You should place any unused shims behind the pulley nut.
You undo the alternator pulley nut,(the top one) there is a slot so you can lock it with a screwdriver. Remove the first half of the pulley, take a shim or 2 out then put them on the outside, then put the spacer and nut back on !!
All the above is correct, but it should not slip on the alternator pulley which should be spinning freely with no resistance. If it doesn't, perhaps you've found your problem as the cooling fan is attached to the other end.
In all you should have (10 i think) you need them all either in between the pulley or outside it. Try taking 2 out but it sounds like your belt is too long
There was 3 on the outside between pulley and nut. Have taken all 3 out and re-tightened. Little to no difference. Can still make slip.
That'll make no difference. You need to remove the ones from between the pulley halves to tighten it.
^ This. The shims to remove are between the two pulley halves. If there aren't any there, it's already as tight as you can make it. You'll need a new belt (get two and carry the other as a spare).
Should be shims between... But if you can't prise the 2 halves apart, this could also indicate that the bearings are going in the alternator and the vibration has cause the pulley halves to lock together... I've not seen them do that before... bearing failure normally leads to the pulley fracturing apart!!
There should be 10 shims in total. Any not between the pulley halves should be under the pulley nut. Some good info about the fanbelt in the link below: http://www.vw-resource.com/fanbelt.html
So as much as I hate to end the thread like this. After changing the fan belt and making sure it was no longer slipping I took it for a spin. Sat at 110C for 15 miles and looked OK. Got on to a longer stretch with a few hills. Temp started rising rapidly and I stopped as soon as I could. I let the engine cool down, but when starting again there was a horrific noise like a smashed bag of spanners. It does turn over but Im assuming I blown it. This is frustrating to say the least especially after all the time and effort, and now harsh lessons have been learnt. So I now have a few decisions to make, and I would like your feedback on what you think would be best in this situation. I have rung round a few local VW specialists and they have all said the same thing. It would be cheaper to buy a recon engine and have us fit it rather than try and fit the existing one. Basically they are all coming in at around 2k to do this. One guy up at Henley Beetles said If I can get a decent recon engine he will fit. Which leads to where can I get an engine. What would you guys do in this situation?
