Hi I have an 05 Cadillac SRX and the automaton transmission shudders. The sequence of events is going up hill, transmission has shifted into higher gear prior to hill. Upon very mild acceleration to maintain current speed the transmission shudders or seems to thump like it wants to down shift, or acts like its momentarily disengaging from the higher gear ...pulling a pressure plate to a higher RPM and the re-engages in the original gear with a thud or thump. It's getting worse progressively and I'm not sure what the ultimate cause is. Has anyone experienced this or know what it is?

I had this problem on my 04 SRX - same thing, going up slight incline @ 30 mph. Like the tranny was fighting to figure out whether to upshift or not. The dealer tried reprogramming the torque converter twice. But that didn't fix it. Then they replaced the torque converter and the problem went away for good. So can I say it was the converter or something else they replaced on the way in/out - who knows. I had this problem on my 04 SRX - same thing, going up slight incline @ 30 mph. Like the tranny was fighting to figure out whether to upshift or not. The dealer tried reprogramming the torque converter twice. But that didn't fix it. Then they replaced the torque converter and the problem went away for good. So can I say it was the converter or something else they replaced on the way in/out - who knows.