got a junkyard 4l80e that i had rebuilt by a local shop, ran it for a year or so and never had a problem, was heading to the track and had a line come loose and spray fluid all over the road, started slipping a little. drove it up an onramp and maybe 500 yards. refilled it to full. drove to the track raced and drove home, been driving it all over and no problems still.

yesterday i get in the truck and drive it down the road, forget something and come back home, maybe 3 miles or so. i park in the driveway and leave the truck running get back in and i have no reverse or forward gears. no slipping just nothing.

shut the truck off and restart all gears come back. drive down the road and its falling out of gear and wont go into overdrive.

i'm going to pull the pan sometime this week and see what the filter looks like, anything else i should look for? seems odd it just all of a sudden did this or is that normal?

 

well checked the fluid and it showed overfull. dropped the pan saw no particles or anything really and clean fluid. changed the filter anyways and refilled works fine now, i checked the level and it shows way overfull. i guess i have the wrong dipstick lol? etiher way it works so i'm happy.

 

well problem is back, started slipping again today and it takes about 5-10 sec for it to engage after you put it in gear. i cracked the lines to the cooler to make sure it was going though and not just cooking since i have no gauge and it seems fine. other then just being overfull i have no idea whats up with it. anything i can check before i take it to the shop monday?

 

these transmissions tend to leak through the harness even the 4l60e. current doesnt travel through transmission fluid. check the connectors on the pcm and the harness on the transmission.