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Th400 won't kick down

12/28/2018 14:58
My th400 used to work quite well. Lately, it has developed a tendency to not kickdown when i stomp it. Sometimes, but rarely. I've had it on jackstands and had my son stomp it with key on engine off. I do get 12 volts at the terminal outside the transmission, and I hear the solenoid click. So I pulled the pan and the solenoid. Checked it all out. Nothing clogged or sticky or anything. While I had it apart, I checked on the governor, looks okay. Got it all back together. Took it for ride and no change. Still doesn't kick down. Any ideas?
12/28/2018 15:03
It's been almost 15 years since I had a th400 in my trans am, so memory is questionable. But back then I was drag racing it and had the "kickdown" switch on a toggle, it would kickdown any time I had that switch on. If the switch is clicking you know you have good voltage and ground circuitry. I'd guess your solenoid is mechanically bad, or the valve is stuck.
01/15/2019 15:32
Any update?
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