Fan belt failures

[technokush]

Hi all, I have a weird thing going on with my fan belt on my 98 A4 TDI. It has failed 3 times now within the last 12 months. Has anyone heard of this happening before? The most recent has just happened and the belt has got jammed up and shredded lengthways. The other 2 times, the belt has properly snapped. It's becoming a real headache, any help much appreciated, cheers, Leo

[Crasher]

Alternator one way clutch failure.

[adamss24]

Dont think they had one way clutch on the alternator on the VE engines, i do reckon its more a failed belt tensioner wich is stretching the belt over the crankshaft pulley and it cames apart in shreds of wires...Had the same thing happening with an BMW alternator, the shop supplied one wich was meant for a mercedes (same size,footprint, same output Valeo unit) but it had a slightly different pulley ! Realised after the new fitted belt shredded that there is a problem and had it replaced with a new unit!

[Crasher]

The two most common engines on the 98 A4 TDI are the 90PS AHU and the 110PS AFN. The alternators normally used on these are;

028 903 027 S (90 amp Bosch) pulley 028 903 119 T approx £92 inc. VAT

028 903 027 T (90 amp Valeo) pulley 022 903 119 D approx £62 inc. VAT

The ETKA description for both these pulleys is “poly v-belt pulley with freewheel and cover cap”