Diesel Bombers - Newbie needs help.. go figure

Have always enjoyed working on my own vehicles, with my dad when I was younger, this is my first truck and I am new to diesel mechanics, I am starting to get to know my 12v Cummins, but there is so much to learn... Almost everyone tells me to get a new vehicle but I am hell bent on proving them wrong about my truck... Still having problems with my little one and now she is giving me shit and not shifting correctly (stupid auto trans). There was a thread a few years back I bumped, fix was never posted. Any help would be great! As i'm sure it wont be my last question.

Thanks and *hopefully* I can get her running as good as the man's LBZ... he makes fun of me all the time :argh: ... so any help would be MUCH appreciated :hellox: