Is the transmission cooling achieved by a radiator within the water radiator as in the 430?

Friends who have 430s have changed radiators as a precaution because of the known problem of water entering the oil cooling system and causing gearbox failure. I haven't read of this being a problem on the 460 and would welcome your thoughts.

 

Yes, unfortunately, LS460 still uses one cooling radiator for transmission cooling (the two transmission tubes connected to the bottom of the radiator) as well as engine coolant cooling. It just happened to my 2008 LS460 at 102K miles. The transmission fluid began to appear in the coolant tank reservoir about a month ago in small pink milky spots/chunks, making my tank reservoir look muddy/blurry. I was about to replace the coolant as part of 100K mile maintenance per Lexus service book and discovered it. I'm waiting for the delivery of one of those cheap "life-time warranty" radiators that RoadFrog/Chris used for his LS460 and will replace the bad Denso radiator this weekend. I'll also do 6 drills and fills of transmission fluid to replace about 90% of the old transmission fluid (I could go to 10 drains and fills to replace 98% of the old transmission fluid, if needed).

 

This tempts me to put a large Hayden external cooler on my '12 and just remove the water radiator from the system.