Why, you may ask, is he changing the timing belt at 46,000 miles
instead of the nominal 90,000? Well, because it's a '94 Accord,
coming up on its 10th birthday in September. I've come to accept,
reluctantly, that I should get the timing belt changed. Actually, I
don't believer for a minute that the belt is anywhere near failing,
but, you know, the penalty for being wrong about that is pretty
severe, so....

But it's not at all clear what else, if anything, I should do at the
same time. I know the usual advice is to change the water pump, and
the balancer belt, and maybe other things, so you can avoid paying
the labor charge all over again if one of those things fails. But,
you know, at 46,000 miles, I wonder if it might make sense not to do
all those other things.

To me, the question is whether, in the process of failing, those
other things would cause a demonstration of the meaning of the word
"interference", or whether they would just make me pay an extra $200
to replace them. I don't want to risk the former, but would be
willing to risk the latter.

I don't know what all is involved, but if, for example, the water
pump is actually driven by the timing belt, then the only way a
failed water pump would cause an interference disaster is if it
failed by freezing up, in turn causing the timing belt to break. If
it just starts leaking, then that's expensive, but not a disaster.
It seems highly unlikely that a waterpump is going to suddenly fail
by freezing up.

And what about the balancer belt (whatever that is)? Is that the
same situation? And are there tensioner pulleys or other things
involved? At 46,000 miles, I'm really tempted to change just the
timing belt, and leave the other stuff alone. I would appreciate
you guys' insight as to which items that might make sense for.

If it matters, I'll probably have the car another three or four
years, and will probably put 5,000 miles a year on it. The next car
will have a timing chain.