4L80E Overdrive Problem

[Brad e]

I have a 2000 K2500 4x4 With a 5.7, 4L80E, 4:10 posi. The truck has 140,000 KM. The Transmision takes itself out of overdrive after about 20 min, after coming up to temp. The trans then starts to shift early and will not go into OD. If I shut the truck off and drive in 3rd it acts normal but no OD. Any info on this would be helpful. Thanks Brad e

[ridgekid]

What kind of tranny work has been done in the past? (Ever change the tranny fluid and filter?)

[Brad e]

What kind of tranny work has been done in the past? (Ever change the tranny fluid and filter?)

 

The oil and filter was done at 70,000 KM Thats it since new. The looks good and dose not smell burnt.

[95Sierra2500]

Sounds like your trans at least THINKS it's getting hot. I would recommend having a shop drive it with their Tech II (or equivalant) and see what the computer tells them. It would be better than guessing.

[unsolved]

The only role heat would play in a tranny is burning fluid/clutch packs, seals heating up and loosing fluid pressure. I would lean towards pressure loss/check balls not floating possibly bad solenoid. Transgo Makes a shift kit thats around 100.00 and fixes most of that s**t.