The 68RFE "Clunk": Is it a tuning issue or a mechanical failure?

[BoostMaster]

My 2016 Ram 2500 has a nasty clunk when downshifting from 4th to 3rd at low speeds. I’ve heard the 68RFE is the "weak link" of the Cummins powertrain. Is it time for a rebuild, or can a simple TCU tune and a fresh valve body save it?

 

[NeonPhantom]

The 68RFE's biggest enemy is low factory line pressure. Try a Line Pressure Booster first; it often fixes soft shifts and clunking.