The pulley setup on Diesel Vanagons is a pain for sure. Changing to the
single belt has 2 problems. The vanagon uses a smaller pulley on the
outside of the water pump connecting to the crank pulley. The larger
inner pulley connects to the alternator pulley. Looking at it, the inner
pulley lines up with the unused inner track of the crank pulley. You
could use one belt to connect all 3 but this would not turn the water
pump as fast, as the pulley ratio would be reduced. Also the pulleys
would be too much in a line and there would not be much wrap around the
water pump pulley. If the belt loosened over time or got wet or oily, or
all 3, it would easily slip. The alternator would still spin so you
would have no warning that the water pump was not giving full effort.
Catastrophe could ensue. Maybe changing the alternator bracket and
finding a small pulley for the water pump would work, but don't just put
a single long belt on the existing pulleys.

Mark

Ken Hunter wrote:
>
> A couple of days ago I posted the following question. Can anybody help?
> ...... Question: My 79 Rabbitt diesel has the alternator-pivot
> tensioning method and works fine even though it has "shallow angle contact"
> on the waterpump pulley. The Vanagon has a awkward but larger angle contact 2
> belt pulley system which is harder to adjust. Scott Foss Turbo Diesels
> offered a single belt conversion for Vanagons using a different pump
> (Rabbitt/Jetta?), waterpump pulley, crankshaft pulley, and one single belt.
> What am I missing here? By looking at the stock Vanagon set-up I could use
> one long belt and tension it at the alternator pivot but maybe the belt
> doesn't contact the pulleys properly? Why not just copy the Rabbitt/Jetta
> layout?