GMC Repair: transmission, gmc serria, version availible

Question
I have a 2004 GMC Serria 2500HD 4x4.

my problem is that when it gets to operating temp
it will not shift frm 3rd to drive/ overdrive.

It has been to our local dearler and the valve body, torque converter, & i beleive the fluid pump assembly have all been replaced. and yet it still will not shift.

what's up

Thank you

Answer
Hi,Steve

 The Dealer didnt mention any internal failure or metal in the trans?the reason i ask is there is a GM bulliten #1577111 for a failing reaction sunshell,this will also cause no 4th gear engagement,there is a more robust version availible.
 The problem your having is when hot/warmed up,this indicates either the 1-2 shift solenoid,a 3-4 shift valve inside the valve body,now they have replaced the valve body,unless the valve body that was replaced is also failing then have them recheck if the PCM has been recalibrated to updated programing.or a PCM that is not seeing the proper indication for shifting into 4th gear,either a failed PCM or a ckt fault to it from the valvebody.
 You may need to try another dealership if the one you went to cant fix your problem,did they road test the truck after the repair?sounds like they didnt really do a good road test to verify that the trans was fixed.let me know if you have further questions,Thanks


ED