ok just ran truck on rack with tires off ground when computer commands 4th it doesn't go it stays in third unless I bring rpms up but as soon as iget off throttle kicks down to 3rd so guess tranny coming back out will post what I find
Allison 5sp: 3-4 shift not right
- Thread starter hallmansauto
- Start date
Why would you check it on a rack? That's zero comparison to driving it down the road under a load.
ok removed trans found that I didn't install Torrington bearing on end of main shaft and c1 drum had to replace reinstalled didn't fix problem so I removed valve body installed a used on shifts great so anyone tell me what I did to valve body fell like an idot for missing bearing but s--t happens
found problem in valve body check ball from transgo kit that goes in trim valve fell out during install remember that trim solenoid falling out will I was trying to hold it in and get retainer installed maybe this will help someone else