Got an elderly Kenmore electric dryer that once in a while won't
automatically shut off - it heats OK, runs through the cooling phase at
the end of the cycle, then just sits there with the drum motor still
running until either I manually move the timer knob a little, or give it
a good thump on the top, at which point the buzzer sounds and it shuts
off.

Another (rare) failure mode is that it'll run, complete the cycle, shut
the drum motor off, sound the buzzer - but I can still hear a ticking
sound afterwards (presumably the little motor for the timer is still
running) - I then have to turn the timer knob a whole revolution or two
before it goes quiet.

I'm assuming it's just the timer that's gone bad (connections all seem
good) - but do those failures seem indicative of any particular timer-
related fault? (living with it is an option, replacing the whole timer is
an option - but so is tearing it apart and cleaning contacts or re-
greasing parts etc. if those are what's bad)

Dryer's a Kenmore "heavy duty plus", model 86566100.

cheers

Jules