Poor 4l80

[Rackii69]

Looking for input. So I replaced trans lines and stupid line pop off from quick disconnect. Drove less then 1 mile to home. Refilled the trans fluid and now slips between 1-2 and engages hard. All other shifts are fine. This is an older plow truck but never had issues with trans before. It is a K2500 5.7 with 4L80. Clutch pack burned ?

 

[stutaeng]

Most likely, yes.

Drop the pan to look for clutch material...

Did you re install the little plastic cap looking things over the quick connects?

 

[Rackii69]

Yeah that is what I was thinking too. Yeah the cap fit snugly over the clip. They were new lines and it was a tight fit on the sides of the trans but clip was on and plastic too. Only thing I can think of is that the flange on the line was not in far enough ?

 

[stutaeng]

I'm always struggling to install those little clips. I didn't know the tube actually just snapped in until recently. What I had always done was remove the clips, insert the tube and reinstall the clips.

 

[Schurkey]

Drove a mile with the cooler tube disconnected?

Wild Guess: Trans overhaul.

Among other things, the geartrain had zero lubrication during that mile. If the pump sucked air, pressure dropped, and friction materials slipped and got hot.