The radiator bladder broke last year and sent the water into the tranny. I flushed it out with 10 gal of tranny fluid. Since than it won't shift automatically. You have to let off the gas and it shifts smoothly. I think it will shift on it's own, but at 3800 rpm. Whe I use the shifter and put it in 2 and shift it manually at about 2600rpm it works most of the time. Any suggestions? It does shift from 1-2 ok.