4L65E shift flare

[79rustyk10]

Well my truck developed a 2-3 shift flare tonite. It's a 2006 silverado, 5.3, 4L65E, 3.42s, 130k on it now... Normal half ton. I wasn't beating on it, just accelerating to highway speed. Its only the 2-3 shift. It's done it twice now, only accelerating to highway speeds. Less than half throttle or so it doesn't do it.

Do you guys have any ideas? The fluid isn't brand new clean, but isn't burned at all either. It hasn't malfunctioned at all since I bought it, until tonite. It's been nothing but perfect for the last 12k miles since I bought it.

 

[K85 Octane]

Can you check for codes?
Maybe it hasn't thrown a check light but something might be stored in the "questionable file"

PS> what's a "shift flare"?

 

[79rustyk10]

It revs up about 400 rpm between 2nd and third. There's no CEL, I'll take it in and pull codes maybe.