Hi everyone! I am new to this site but not new to the Duramax. I have been fixing vehicles for 11 years. Currently I am working on a customers vehicle. It is a 2009 chevy 2500 HD with the LMM. Fass 150 GPH lift pump and Transgo shift kit. The vehicle has DSP 5 EFIlive custom tuning by Idaho Rob. Max effort tune for 530 rwhp. And also a 5 inch turbo back flow pro exhaust. My customer regularly drives the snot out of this truck. Last week Tuesday during a wide open throttle acceleration the Allison suddenly lost 4th, 5th and 6th gears. There was a P0776 Pressure solenoid 2 stuck off. A line pressure test quickly showed a massive leak as soon as the C2 clutch was commanded on. I tore the trany down yesterday fully expecting a c2 clutch seal to be torn. To my surprise the C2 seals were all ok. Further inspecting found the root cause was inside the Front support housing. The stator shaft turned inside the front support and opened the C2 clutch fluid passage to the trany lube circuit. Has any one else seen this? I am confused as to what can cause this. I want to be certain that this wont happen again. I have never hear of this before. If this is a common problem what is the fix?
Allison 6sp: no 4-5-6th gears
- Thread starter ripsnortinLB7
- Start date
Do the pics in this thread match what you're seeing?
http://www.duramaxdiesels.com/forum/showthread.php?t=49153&highlight=twisted+splines
http://www.duramaxdiesels.com/forum/showthread.php?t=49153&highlight=twisted+splines
No this picture does not match. The stator shaft is mounted to the front support. The stator shaft is the large shaft that sticks out the front of the trany and splines into the torque converter.
I have already ordered a suncoast SunGMAX-6R-3 overhaul kit from Adrenaline Truck performance. I have also ordered a triple force coverter from BD Diesel.
Does anybody make a stronger front support and stator shaft? Or do I have to just order the shaft and front support from the local GM Dealer and hope that the new shaft will not spin?
Better send that converter back and order another
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I have seen this once were the stator support spun in the housing, what I have seen more is the stator support push forward out of the housing. The latter I have only seen I junk yard core tranys though. I am unsure as too a culprit of ether problems
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My bad, I call that an input shaft. Tried to help. As usual, I should've just deferred to the Allison gurus.
It happens from time to time. There is nothing stronger and really doesn't need to be.
Take the above advise and stick with Goerend or Suncoast converters.
Take the above advise and stick with Goerend or Suncoast converters.
Thank you for your input Mike L! Thanks to everyone else as well! The DB diesel converter has not been shipped yet. I am from Canada and getting a Suncoast converter sucks because of shipping such a heavy item across the line. I will do my best to get one tho. Goerend is also a US company I think.
Where in Canada you from? I hear you on the shipping but it will be worth it with a better product.
I have a question for Mike L. I have seen some nasty pictures of death to the C2 hub and P2 On this forum. I understand this is caused by a massive tieup between the c2 and c3 clutch.This truck i am working on has tuning from Idaho rob and as i stated I am installing a suncoast kit. Do i have to install a wavy plate in the c2? Or does the tuning from Idaho Rob prevent this from happening?