i have a 2006 volvo with isx with the eaton ultrashift. the problem im having is the truck wont shift out of first gear. i just replaced the x/y shifter. when i push the truck in drive it starts out in 1st and when it get enough speed it acts like and trys to shift into second gear but it wont so it drops back into 1st. it will keep doing that. there is no codes in computer. when it is trying to shift i can hear it trying to go into gear slight clucking noise. the clutch is less than a year old. I was playing around with it in manual mode and got it to skip past 2nd and it went into 3rd no problem and when i pushed it to go into 4th it wouldnt shift into 4, it tried but then went back into 3rd. any clue to whats wrong or what to check?