[neon_rt]

There was probably not much wrong with the trans the first time. It sounds like a computer problem. There has been several rewrites of the transmission computer code over the years. I take it that the mechanic you speak of is a private mechanic and has never loaded the latest flash update to your trans controller. The trans controller may actually have some defect, that can probably be determined by the dealer. There is an extensive procedure that has to be done after a rebuild to "condition" the trans controller, otherwise the rebuilt transmission can be damaged. The procedure involves lifting the drive wheels of the ground and doing 40 to 80 repetitions of 0-30-0 and 0-60-0 and then some actuall drive cycles 0-30-0, 0-60-0. The procedure allows the computer to learn about the new transmission. Skipping this step can lead to premature if not immediate failure. If the mechanic knows nothing of the conditioning procedure, you have the wrong mechanic.