Hi everyone. I have a 2002 lb7. My problem first started a few months ago. i was driving about 50-60mph, went to get on it a little bit and then all a sudden the rpms jumped up and acted like it was stuck in third gear. I took it easy the rest of the way home, when i parked in my driveway, i went through all the gears and noticed i didnt have reverse and the R was flashing. Shut it off went inside and got on the computer to do some research. Most everything i found was replacing the NSBU. Next day i started the truck and everything was fine. So i drove it for a while longer till it went into limp again, this time on the interstate trying to pass someone. So then I replaced the NSBU. While replacing i had a few codes that i cleared. P0234, P0700, P0735 and P0840. With codes cleared, i drove truck home and it went into limp again as i was trying to pass someone. I pull over, clear codes and the truck is fine again for a while. Seems like if i drive truck taking it easy, i have no problems. But getting on it at all, it goes into limp. Anyone have any ideas what the problem is? Any help will great. Truck is stock as far as i know. Just got it last fall.