Did you have a coolant flush performed?
The radiator has an integrated transmission cooler , and the pipe couplings are located at the bottom of the radiator. Have they been messed with?
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car