I have had this problem for a while now. The truck will shudder on the downshift when I floor it, quite badly, like it cannot decide which gear to kick down into. When it does finally complete a downshift, it seems it goes a gear too low and only stays there for a second before upshifting. It seems this is only happening when the transmission temp is colder than 40 degrees C. Anyone else experience this? The dealer could not replicate the problem when I had it in. Might be time to have a tech ride with me to feel it I think! I have read about a similar problem with the 545rfe in grand cherokees a few years ago and I am wondering if it is just a TCM problem. Can't be good on the tranny either way!