I reported a bit ago about yet another (four in less than a year) broken
alternator mounting bolts in my 1.9L Westy. No one seems to be able to
figure out why these bolts (the ones that hold the alt. mount to the engine
block) keep shearing, though I had a lot of good suggestions.

Here is what I pieced together, in case it helps anyone as Things to Check:

My engine doesn't have a vibration problem. The belt doesn't have something
wrong causing it to vibrate the alternator (no comments, please!). The
alternator isn't out of balance. I loosened the belt to slightly less than
spec.

It dawned on me that what I do have is a bad case of clutch chatter. I
suspect a leaking front main seal. When the clutch heats up from a bit of
use, the chatter goes away until it gets cold again. I think the vibration
caused by the chatter eventually shakes the alternator mount bolts a wee bit
loose, which causes the mount to shake more, which causes the bolts to get
looser... Eventually the bolts break, snap, shear off.

Secret: KEEP YOUR ALTERNATOR MOUNT BOLTS TIGHT!!

Problem: you can't tighten them because either the water pipe (from pump to
right head) or the oil filler tube is in the way and must be removed to get
a wrench on the bolts. This causes a lose of one fluid or another, and is a
pain. (I think just removing the oil filler tube at oil change time wouldn't
help, as I THINK the water pipe is still in the way. Not sure.)

Anyone with a suggestion, please make it. I've tried every tool I can think
of to get up in there, nothing fits. The wrench goes on, no room to turn it.

From now on I'm going to check those bolts every week or so. Otherwise, the
threads into the engine block (soft, due to it's being made from aluminum)
will tear out and then you've got an engine removal, re-weld job on your
hands.

BTW, don't recommend using thread-lock on the bolts, as getting the sheared
off piece stuck in the engine block out would become next to impossible.

Steve
84 Westy