Having possible trans motion troubles on my pulling truck. Have a 4th gear start tune that I have ran for years. Hi stall suncoast converter. After going to the engine dyno and placing the motor back in and it sitting for 6 months with our current state. The truck won’t shift out of first. Speedometer is reading when moving. No codes, only code that has come up is a po2764 replaced solenoid, still same problem wiring harness was new 2 years ago. Had zero issues when I pulled it into the shop to pull motor only thing that was swapped on trans was the converter, but have a hard time thinking that’s is what is not allowing it to shift, any and all help appreciated
6 speed Allison only goes to first gear and reverse
- Thread starter Lbzpuller3
- Start date
Have you tried another TCM (and made sure TCM is getting power), and are you sure its 1st, not 3rd? What you describe sounds like Hydraulic default.
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Sent from my 2PZC5 using Tapatalk
Yes tried known good tcm, it shifts in 2wd all the way to 6 in 4 lo for pulling for some reason I can’t get it to go into 4th gear as the tune is designed, and works on any other lbz I plug tcm into.
Why do so many people replace solenoids when they see a code? It's almost never a solenoid. try looking for a bad ground at the TCM or harness.
Because I had one and it was quick and easy. Update the truck will shift through all the gears in 2wd in 4lo it won’t go into 4th gear as the tcm is set up. Went through all wires harness is 2 years old truck sits as it’s dedicated puller in climate controlled shop so no mice or anything like that have been chewing on wires. Still think it’s a ground? Or can something else be stopping it that it’s looking for reference from something.
