4l80e - Converter unlocks while coasting on interstate?

[Alex_M]

Hey all! This is actually a Silverado question, but I was hoping one of you kind folks may have some insight.

I've got an '02 2500HD with a 6.0/'80e. When I'm driving down the interstate and let off the gas it acts like the converter unlocks. When I hit the gas again, even easily, it flares up about 500-700 rpm and then locks back and the drivetrain feels like it "springs" back, for lack of a better term. This also happens when pulling out from a stop, where I'll give it light throttle and it will rev then catch and then I can lean into it more.

Anyone have any insight? The truck has 235k miles on it. Allegedly it was not towed with much, so it shouldn't be worn out yet in my mind.

Thanks!

Alex

 

[Bill 1960]

Every GM trans I have owned in those generations does that. It’s how all the 4LxxE are programmed AFAIK. Normal.

The TC clutch is only programmed to lock when positive throttle is applied between a minimum and maximum percentage. Too little OR too much and it will unlock.

 

[Alex_M]

I've had a couple Tahoe's this body and unfortunately I think this is a bit more severe.

Actually, an additional detail I forgot. On two occasions pulling out from a stop, mid throttle, it has revved way up (~3000 rpm) and then suddenly caught violently, spinning the tires and all.

 

[rockola1971]

I've had a couple Tahoe's this body and unfortunately I think this is a bit more severe.

Actually, an additional detail I forgot. On two occasions pulling out from a stop, mid throttle, it has revved way up (~3000 rpm) and then suddenly caught violently, spinning the tires and all.

There is a TCC lockup solenoid and it sounds like yours could be hanging up.