[Vwdiesel] Old VW alternator alignment problems

[Doyt W. Echelberger]

Talked to a VW master technician today, mainly about old Rabbits. He has 
grown up with diesel Beetles and Rabbits and Jettas through the 70's and 
80's. He revealed something about why old Rabbits, Jettas, and other VW 
diesels eventually develop alternator problems involving alignment of the 
drive pulley....the pulley driving the alternator no longer runs in the 
same plane as the other drive belts, and the result is that the alternator 
drive belt flies off and self-destructs.....also leaving the water pump 
without a belt.

He said a frequent cause of the mis-alignment was deterioration of the 
rubber bushings in the brackets where the alternator is mounted.  Diesel 
fuel affects the rubber bushings....they deteriorate and let the alternator 
vibrate/wobble,move...... somebody notices the  "loose" alternator and 
tightens up the bolts, and the alternator shifts to a new alignment that is 
different from where it needs to be.  Time passes, more rubber 
deteriorates, the alternator is even more loose and wobbly, and gets 
tightened into an even-more-extreme misalignment......process repeats over 
decades and finally the belts self-destruct and won't stay on the pulley.

The other big cause of belts being out-of-plane is the multiplicity of 
pulleys that are available for running VW alternators. As original 
alternators wear out and fail, replacements are swapped in and they don't 
always have the correct pulley attached for that model. I knew about that 
problem, but was unaware of the deteriorating bushing process.

Hope the technician knows of what he speaks. Maybe the list can confirm it.

Doyt