There has been a lot of discussion of severe damage as a result of
failure of the timing belt on the I4 engine.  The tensioning of the belt
for older I-4 VW engines is static (using roller 026 109 243J bolted
solidly to the cylinder head) with tension defined only by the
installers skill and experience.  The Bentley instructions to twist the
belt easily does not seem to be very precise and there is probably a
large variation in the tensioning of belts by non-professionals doing
this very important task.  The newer engines have dynamic tensioning
devices that are spring loaded with the belt tension determined by the
device.  Do the newer devices work better with fewer belt failures?  Can
older engines be retrofitted with the newer rollers such as the one for
the 2000 Golf AEG engine (06A 109 479A) to insure a more accurate belt
tension adjustment?  If upgrade is possible and desirable, which of the
available adjusters would be best (026 109 243J, 038 109 243H, 038 109
243G, 028 109 243F or ???)?

Ed McLean