We've got an 07 4.2 that's just touching 40k. For awhile now we've been experiencing an issue where if the car is loaded, or going up hill, if you really stomp it to pass it'll downshift to 4th and then as it revs up and goes to shift to 5th the whole car will buck and there will be some really loud bangs from the transmission.

It won't stop until you lift off the gas (your first instinct anyway since the bucking is extremely violent) and then it'll shift up.

We're working with the dealer, and they've indicated there's a TSB for 'rough shifts' that they've performed and that now they're replacing a 'throttle body' in the transmission? I don't know enough about transmissions to know if the TCU has throttle bodies to control the transmission fluid.

Anybody experience anything similar?