I rebuilt my Allison on my 2004 LLY and have over 700 miles on it already. The only problem I am having is the TC is not locking up in the high gears. Tow haul mode will not cause it to lock up and took it to a diesel shop for a tranny reflash and they tried to manually lock it up with a TechII but unable to do so. Lot of times it feels like its trying to push thru the breaks at stop lights and also feels like there is a load while accelerating, causing my truck to smoke more. It has thrown the P0741 code. Also causes the tranny temp to creep up to 210+ degrees. Put it in reverse today and it took off like a rocket then it jumped and slowed down back to "normal reverse speed". Got out of my truck and noticed it sounded like grinding noises coming from the TC area.
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