weird 1-2 upshift when cold

[7th son]

My '03 D/A(900 miles) has a noticeable lag in the 1-2 upshift, especially prominent under very light throttle pressure when cold. It's almost like it stops momentarily once the shift begins, then decides to start up again and complete the shift into 2nd. Once warmed up and with decent throttle pressure, the symptom goes away.

Is this just because the truck is new and tight, or is it characteristic?

Any need to have it checked out by the dealer?

Ed

[Allison Jettester]

What's happening is that the engine is defueling and allowing the shift to complete when cold. Mine has always done it. This is done because the trans fluid is cold which will cause the clutches to slip until enough fluid gets to the piston that locks the 2nd clutches. I had a 95 w/4L80E that didn't have this feature and I could feel it slipping on the first shift in the morning. It is a good thing.

[rtquig]

Mine does it when it is cold and also sometimes when you don't come to a complete stop and then take off again.