4L80E Shift flare

[insidethreat07]

Truck is a 2000 Silverado 6.0 with the 4L80E trans with 250k miles, no burnt fluid and it still looks pretty clean. After shifting into 4th when the converter locks up and drops 4-500 rpm, every once and a great while there will be like a rpm flare up 3-400 rpm then drops down again quickly. Happens maybe once a week. Any advice on what could be causing this. I did some reading around and possible a solenoid? It happens with and without towing my car and car trailer behind it.

[Tammy20002500]

I've experienced this as well. I've owned my 2000 2500 since new, and once in a while, while on a long flat stretch with cruise control on, the torque converter seems to unlock and re lock periodically causing the rpms to jump 400 or so. There is no shudder symptomatic of a slipping converter, and it has never thrown a code or run hot per the gauge. It has been doing this periodically since new and the truck now has 171,000 miles on it. (I've noticed that it usually happens when the AC is on and speed is high). Thinking maybe the brief spike in throttle to compensate for the a/c compressor cycling on/off is sending a code to the tranny to unlock for a little more HP.  Anyway, my point is that its never been a problem. just a thought....