About a year ago my 07 expy trans made a loud bang and just stopped moving. Ive rebuilt tons of trannys but never one of these. Turned out the front pump gears grenaded. 140k on it so i decided to rebuild it. Pretty easy to rebuild with all new clutches steels amd seals new pump and converter. But now the thing bangs and surges like crazy mainly in OD. Never did this before. The kit came with new seperator gaskets for the VB but the oem plate had rubber embeded into it. Kit said to scrape that off and use the gaskets. Could that be the problem? Ford has flashed it with up to date programming. But they say the trans is shot and needs a new one. Figured they just want to sell me a tranny. Any ideas guys? Im losing hair over this.