I have a Kenmore dryer (model no. 110.96588210) that starts only when
cool, and sometimes turns off during a cycle when the motor heats
up... and always has a deep groaning sound when
starting up...

I was advised by one of the experts in this newsgroup that it needs a
new motor (thank you, Todd).

After replacing the support roller wheels (all 4) - which was much
needed, as each of the older ones was about 1-2 mm shorter (worn out)
in diameter, the dryer's drum rotates much more smoothly and is
certainly less noisy - but... the problem described above still
exists.

So, I came to the conclusion that the expert is right and I am about
to order a new motor for my dryer.

However, as someone who used to be familiar with the theory behind the
operation of electric motors, I am curious what could make this motor
behave so strangely. Isn't a motor either "dead" or "alive"? I could
understand an unusual load (i.e. one that the motor was not designed
for) overloading the motor and leading to its thermal protection to
shut it off. But now, all is supposedly well - so why would it
overheat?

Could this be indicating some additional *mechanical* problem,
stemming from some wear in the motor assembly itself? (after all, it
is 12 years old)

Just curious. I would appreciate any tip or hint in this regard.

Thanks,
Sam