So I have no clue what is wrong with my truck. I have the 3.5L and When I want to pass someone on a 2 lane road or bypass and I floor it, it will down shift and hit the Rev limiter at 5k RPM and will not shift until I let out of the trottle. Also does it from a dig. Normal everyday driving it shifts fine but only does it when in high RPM. Took it to the dealer and they don't know what's wrong with it either. The only thing I have done transmission wise is install a low pro cross member. When I did I used my jack to support the tranny when I dropped factory x member. I didn't raise it up or let it drop. I've checked the transmission fluid and it seems fine. Has anyone else had this problem or know what I need to do to fix it? Thanks in advance!