i have a 03 tahoe Z71 the trans will act like it just gos into nuetral it does not slip at all when you drive it it will go between a 1/4 and a 1/2 mile and act like you put it in nuetral no gears work but if you shut it off for a couple of minites you can drive it about a 1/4 mile no sliping and then just like you put in nuetral any help would be greatly apreciated thanks

 

tranny needs to be rebuilt. My uncle in FL can get a chevy 4L60E rebuilt for around $1000~$1200 with a shift kit so that the shifts are firmer but this really extends the life of all transmissions...
I dont know where you live but this is just to give you a ball park idea of price...