The difference between 3rd and 4th gear is the band being applied. That's done by the servo. I would pull it and make sure it's definitely in there correctly and you didn't rear a seal. Make sure it's together right too ... I have a Vette servo in my rebuilt 4L60E, no tune (95 TBI) and it shifts great. You don't need a tune to make it work.
I think I'm just gonna pull it out & throw the stock one back in for now & see if it works correctly.... I do t know how many miles are on the tranny but the truck had 176 & change when I put the new motor in, so maybe the servo is too much for the mileage on the tranny that's it's causing problems, hopefully this isn't gonna cost me $1K for a rebuild now, even though I probably need it anyway because I noticed a small amount of fluid near the starter like almost dripping down from above it onto it..... I let you know & I know no tune is needed, i've done these on the last couple trucks I've owned....
check the o-rings!! a leaking one will cause major problems. i also have a 95 tbi stock tranny with really high mileage and no tune is necessary. it shifts fine
I looked at the o-rings on the servo kit itself and no leaks, I installed the new o-rings from the kit....
Even though I'm pretty sure it's installed correctly, does anyone have a picture of the way the servo is actually installed or put together before it's put back in?
Thanks for all the info & feedback though guys! The info is really appretiated!!!
