i just installed a rebuilt 4L60e and its running ok. but im noticing a long shift from 1st to 2nd and it seems to fall on its face and then it'll hook up and go. also while on the highway i also notice that the car will want to slip out of overdrive and go into third while very little throttle presure is applied. i can see it down shifting when i punch it but when i just give it mild throttle it slips into third and stays there until i let off completely. what is the problem and would installing a corvette servo help my problem? any other possible fixes would be greatly appreciated!

 

you have a problem with the band, the band is used in 2nd gear and 4th gear