[Vwdiesel] Old VW alternator alignment problems
Doyt W. Echelberger
doyt at buckeye-express.com
Tue Oct 9 12:57:06 PDT 2007
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
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