Hey everyone, I am the proud owner of a 2002 duramax 2500HD and unfortunatly I am having tranny issues, I have the allison 1000 and its having severe shifting issues, it started when I hit a pothole this last spring, it started out downshifting really hard, then it went into 3rd gear limp mode, now its acting like its in neutral when i'm in drive, i have no forward gears in 2H or 4H but can move in 4L. I have changed the NSBU switch, output speed sensor, the pressure solonoid B and the TFPS manifold. Its still giving me the p0872 code, one time it"ll say that shift valve E is stuck, then it says C circuit something. when i dropped my pan I had metal slivers on the magnet, i think my front pump is going out in my tranny and i have stuff in my valve body that needs to be cleaned, and replace my stuck E valve. Is there anything else that would make it default to neutral when i'm in drive and reverse in 2H and 4H?? I need all the advice I can get. Thank you Debbie