ok, i have a built 4l60e, and it ha been acting up, i have had it rebuilt 3 or 4 times, cause i kept burning the 3-4 clutches up. well i was driving the car a few days ago, and 1st is fine, pulls hard, 2nd is fine, pulls hard, then it goes to 3rd, and red lines, let out of it, and it just idles real slow, so i give it gas again, goes to redline again, i figure the 3-4 clutches are gone again . so i stop, and pull over, look at the fluid, and it looks ok, doesn't smell burnt or anything, so i am like i get back on the road and run it throught the gears this time, and everything is fine till 3rd and OD, seems like they are not even there if you try to accelerate. i turn around and go home and park it. frustrated at the situation, i look at it the next day , and go try driving it again, to see if i can hear anything unusual, get out on the street and 1st is good, second is good, and 3rd is good, you feel the TC lock up, and thn it shifts to 4th fine and TC locks up, all of this at idle, so i get to a straight away and slow to about 20, and nail it. as usual it turns sideways blowing the tires of in 1st and second, and then catches 3rd and pulls hard to 125 and shifts perfect to OD, and pulls hard. so i slow down and run it through the gears this time, and it works perfect again. so i was like ok, it must have just been acting up, all is good now. well friday i go out and drive the car, and low and behold, 3rd and OD act like they are not there, so i get to my destination and park it, get pissed off, cuss at it a while, and then decide to go home, and the Damn thing works perfect going home. anybody give me any idea's??? i thought it might be a shift solonoid, but i heard if it was a shift solonoid, it would shift throught the gears manually fine, but just not if you put it in OD and let it shift itself, so i am confused