okay so I had my 4l60e rebuilt, had it installed on my untuned cammed 6.0 that I recently swapped. I got the trans in and drove it 35 miles home. it did fine shifted good and all. Only problem was the line came off the cooler where the e clip snaps in. fixed it filled with fluid again and drove a good bit more. nothing else happened. I went the next morning to have the truck tuned for the cam and the line blew off in a different place so I just slid it back on and double clamped it. filled with tranny fluid again and made it to the shop. he street tuned it and did fine. drove ten miles on tune and go to stop at a redlight and truck acts like its in neutral and revinng kind of high still. and when I do get stopped it shifts hard back into drive. so I stop check the fluid and it was full. I added a little bit and kept driving. when I got about 30 mmore miles I stopped at another redlight and the same thing happened when I took off in drive it shifted to second and then the engine just revved. so I pulled into gas station to check fluid again it was full. so I filled it 1 1/2 quarts over because I called several people and they said it wont hurt it. so the I put it in drive and it pulls itself about 100 feet when it quit pulling again. stopped and shut it off. made sure all connections were tight under truck and they were. crunk it back up had no forward gears but had reverse. then I manually shifted into first and it went in drove it I shifted to second went smooth, then hit 3rd went smooth again pulled it into drive and it hit 4th and the converter locked like its supposed too. stop at a redlight and I shifted back to 1st and continued again with no issues. then I tried drive again and it shifted into second and it quit pulling again. pulled it into d2 and it shishiifted into there no issues. made it home just fine. can anyone help me out? is it tune related or what? it was fine before the tune

 

Man you got a lot going on there so lets start from the beginning

When the Cooler Line blew off the first time, how much fluid did you lose and did you drive it after the lose of fluid ???

The second time the line blew off how much fluid did you lose and did you drive it after the lose of fluid ???

Where I'm going with this is not a good place but.... if you ran the trans low and hot and then put it on a dyno even know nothing happen "on" the Dyno there is a good chance you burnt it up

PS
Whoever told you overfilling a transmission cant hurt something is wrong.

Overfilling an automatic transmission causes the fluid to foam, leading to erratic gear shifting, oil starvation and transmission damage.

 

Overfilling a 4l60e 1/2 - full quart will not result in foaming.

It is common to overfill a 4l60e to help prevent the pan from being sucked dry during wot for the 2-3 shift when the 3-4 clutch pack is applied and the 2-4 band is released

 

I felt the line pop off the first time. I just so happens to be pulling into a parts store as soon as it happend I fixed it and refilled the trans. Drove it around all weekend. And then this morning it happend again I spelt the fluid burning on the headers. I checked frequently to see if it would happen. I stopped immediately and refilled it again. Then drove it the rest of the way to my tuner and he drove it around a good bit tuning it. I leave the shop and get 10 miles down the road and it started happend

 

I agree but...

 

98 ceyanne she said it wouldn't hurt my tranny either. Especially with a shift kits it's okay to over fill it

 

Thats great if you didn't lose much fluid and didn't drive it low or hot because you can burn one up very easily. Based on you saying it was fine and then all of a sudden it wasn't is what scares me. Man I hope you find something simple and all is well

 

Rob, thank you. I hope it's simple. I think it's weird it's fine for 4 days and then 10 miles after a tune it does this

 

A lot of builders have a refresh service. For instance: FLT charges $250 labor + parts. Might be worth an inspection.

Braided hose with AN fittings is the way to go.