Kenmore electric dryer not shutting off


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
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Jules Richardson wrote:

Not helping, but my elderly Whirlpool also no longer kicks itself to "off" after a cycle. I just remember to go in and turn it off.
Jon
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On Tue, 03 Aug 2010 11:08:13 -0700, Jon Danniken wrote:

Yeah, I think that's where I'm heading with this one. I pulled the timer, and there's a little snap-ring around the timer shaft which holds things together, and I don't have a suitable tool to remove it (at least, not without damaging it). If the timer fails completely then I'll dig further, but for now I think it'll just live with it.
It's 50 bucks + s/h online for a new timer, and I can pick up a used dryer for that around here and end up with a motor, sheet metal etc. from the old one to use on projects, so it's not really worth actually buying replacement parts for it :-)
cheers
Jules
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On Tue, 03 Aug 2010 19:37:22 +0000, Jules Richardson wrote:

Blast it with compressed air then apply some WD40...may loosen it up
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Some driers have a humidity sensor. Check, see if the vent hose is clogged.
If it is the timer, some electrical contact cleaner, followed by some spray lube may do it. Worked for my washing machine timer ($75 on ebay, no longer available at my wholesale house.)
WD is fairly short lived spray lube. PB Blaster may last longer.
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On Tue, 03 Aug 2010 19:43:22 -0400, Stormin Mormon wrote:

No problem there (part of the reason for diggin in the machine was the timer, but part was pulling the thing apart to give it an annual de- linting - turned out it wasn't too bad inside at all)

Yeah, that's what I'll do when it dies completely I think - to really get at the contacts I need to get the face-plate off, which means removing that snap-ring, which means buying yet another tool... :-)

Agreed - I hate WD40; lasts for a short while, then just attracts dirt and wrecks mechanisms further. Good for temporary fixes, but it's not really a long-term solution to anything.
I can see grease on the timer's shaft, and it turns easily enough, so I don't think that's the problem with it - I expect it's either worn contacts or worn cam gears (from what I can see through the holes in the face-plate the cams are plastic, and if they're shot then it's pretty much Game Over)

I'm not sure of the wisdom of using peanut butter... ;-)
cheers
Jules
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On Aug 4, 9:23am, Jules Richardson

You may be able to fix it. Cleaning and adjusting the contacts is often possible on that sort of device. The design is that it is supposed to turn off the drier first and then a short period later turn off the small motor on the timer. That's why you discovered that the timer still runs after the unit shuts down, that's normal. Some of them turn the heat off even earlier so there is a brief cool down cycle. It sounds like yours has gotten sloppy and is turning the timer motor off before it turns the unit off.
Cleaning the contacts may help. Normal adjustment is such that the contact not only closes but also causes the back contact to move a little as well. This causes a slight "scraping" of the two surfaces that helps keep the contact clean. You can usually adjust contacts by carefully bending them. Figuring out which contact does what first by looking at the schematic or tracing wires will help troubleshoot as well.
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Second that
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Jules Richardson wrote:

Aye, timers are spendy mechanisms. You might try ebay, I've picked up a number of parts for older appliances on the cheap (dunno about dryer timers, though).
And you can pick up a set of snap ring pliers pretty cheaply at a hardware store, with different tip extensions. They come in handy over the years when you need them.
Cheers,
Jon
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