I have an '01 Dmax that has had shifting issues before and after a rebuild. I get a double "bump" type of shift from 2-3 under easy acceleration and a HARD flare on the 2-3 when under a harder acceleration. I've had it to the Allison dealer 4 times, purchased an upgraded TCM/ECM (SoCal Diesel), have done a continuity check on the external tranny harness, replaced the leaky internal tranny harness, ohmed all the solenoids and can't find the problem. Someone mentioned getting an EFI unit to log the shift data so that someone (who?) could read it and determine what is going wrong? I'm not opposed to buy the EFI and getting a couple tunes IF usable data can be retrieved so that my truck is fixed!