2001 , 5.9LTR, AUTO 4SPEED, RECENTLY I HAD SLIPPAGE IN SECOND GEAR THEN I SERVICED THE TRANNY AND NO IT REVS HIGH BEFORE SHIFTING TO SECOND AND IF I'M LIKE GOIN 30 MPH AND START TO EXCELLERATE BARELY IT WILL DOWNSHIFT TO 1ST, IF I MANUALLY SHIFT TO SECOND TO EXCELLERATE IT WORKS FINE, COULD THIS MEAN A TRASH IN VALVE BODY, THERE IS NO MORE SLIPPAGE, I WAS GOING TO GET A NEW VALVE BODY BUT WANT TO MAKE SURE.

 

YOU NEED TO ADJUST THE KICKDOWN ON THE TRANSMISSION.

 

i had missunderstood your transmission problem. I thought you were
saying it shifted late. i had the same problem after installing a b & m
shift kit in my trans. It sounds like you have a valve not opening fast
enough. In my case I had cross leaks between the passageways in the
valvebody. Unfortunatly one of the leaks was pushing pressure into my
reverse valley while driving foreward. I went to back up and realized it
had completly smoked my reverse band.