i just finished rebuilding my nv 4500 transmission and it works fine but some times when i shift to fifth gear the shift lever goes into the fifth gear posistion but it does not actuaily move the lever fork inside the transmission that then causes the shift lever to be stuck in the fifth gear posistion so i have to take the shifter off and shift the shift forks back into neutral . then sumtimes it shifts into fifth just fine . i always make sure to put the reverse shift collar and the fifth shift lever in line with each other when i put the top back on so i know thats not the problem . does anybody have any other ideas ?