I have an 03 lb7 with allison, just had rebuilt with suncoast g-max 5 kit w/ midwest converter (stock stall). Have trans in truck topped off with fluid, replaced nsbu sitch, internal harness, and pressure switch assembly. Trans will engage into reverse and drive, but will immediately "range shift inhibited" and goes to nuetral. Engine light comes on with code: P0700, P0841, P0872, P0873, P0875. I have checked pump pressure, and it is within spec... 250+psi at 2200 rpm in park.
Allison 5sp: Trans problems after fresh rebuild
- Thread starter Jon21holmes
- Start date
Who built the trans? How did you check pressure?
With all the great converter companies out there; why in the hell did you choose them? If your builder chose that converter; why in the hell did you choose him? Why is he not fixing this? How much did you pay for this so called build?
I built the trans myself. The trans was working for about 20 miles, then it stopped moving. Trans has been completely torn apart and reassmbled since. Conveter choice was from a buddy who used to work for duramaxtuner.
Pressure was tested with a 500psi guage at the port next to spin-on filter
Pressure was tested with a 500psi guage at the port next to spin-on filter
Your problem is not pressure; it is the clutch packs are not getting the pressure. Without knowing what you did inside; it's any ones guess.
Okay, so trans will be coming back out an be sent to a reputable builder in the area. Thank you for your professional opinion. Everyone i've talked to believes it's an electrical problem, but they seem unsure.
Sorry to hear of your issues... I like building/working on shit but when it comes to transmissions i take mine to the best and have never had any issues 
It seems like everyone is trying this now days. All with the same result.Sorry to hear of your issues... I like building/working on shit but when it comes to transmissions i take mine to the best and have never had any issues
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It seems like everyone is trying this now days. All with the same result.
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X2.I also noticed a trend on the diy trans builds gone bad.Allys are great until they dont work.