[pol441]

I have a stock early 2004 duramax with the allison automatic. Over the past few weeks I have been having sporatic problems with the transmission. Under heavy acceleration (pedal to the boards) the engine hits the shift point rpm but the transmission will not shift. I have to relase the throttle a little then it will shift. This happens shifting from 1st to 2nd and 2nd to 3rd. I have also noticed that under normal conditons the transmssion seems to be searching for a gear or down shifts at times when its not required. I friend told me that it is probebly an external shift regulator (he was not sure of the exact wording) can someone give me info thanks

 

[Mike L.]

Change fuel filter first. Then come back and tell me what changed.
mike

 

[RayIN]

I changed my fuel filter yesterday, it was just over 15K miles. The AT was shifting strangely, and I remembered reading that the fuel filter would cause this if it needed changing. Right on target!

 

[Monster truck]

try shifting it manualy and see if it will shift under the pedel to the medel, this almost sounds like a vb going south, have you had the trany serviced reguraly and all that good stuff?

 

[newman]

Pol441: I am having the same problem. 04 duramax, 35000 miles, used for some light towing. Most of the shifting is sporadic, but the major issue is that when full throttle acceleration the tach rpms get to 2800 and the trans will not shift from 3rd to 4th and the engine stays at that rpm until I let off the throttle, then it will shift. has anyone come up the cause of this problem?

 

[BigRedChevy]

Try you fuel filter and then you spin on tranny filter.

 

[newman]

wont start

I changed the fuel filter, forgot to fill it first. It started then quit. I removed the filter and filled it with fuel, reinstalled it. now it wont start. what do I do now? HELP

 

[newman]

forum came to the rescue

a little good advice from the friendly folks on the forum.. I learned that the button on top of the fuel filter housing is a priming pump, a few pumps and it came back to life easily