Just gonna start a new thread for this so I can get all the info in one post. 02 ccsb lb7 4x4. Has 290k on it. I've had it for 15k and trans hasn't been rebuilt in any previous owners. So when I was running ppe on the stock one it limped and was all screwed up, yes I know I shouldn't run the tune. So I picked up another allison on Craigslist, supposed to have 120k miles and was shifting good in the truck it was pulled from, I still keep in touch with the guy I bought it from. So took the truck and got that tranny installed, got the truck back, went into limp mode becuase of a valve sticking code, so I pulled the valve body from the previous trans and put it in the new used one in the truck. Now the truck won't move or go into any gear at all. The gear selector light flashes when you try to put it in gear so I replaced the nsbu. And still nothing. Doesn't even throw any codes now. Any help?? It has plenty fluid in it and all switches are hooked up.