Nissan Pathfinder, Xterra, and Frontier all share a problem prone radiator. Automatic transmission heat exchanger in the radiator breaks and allows coolant to enter the transmission resulting in transmission failure. A 10mm wrench is required to check the trany fluid, it should be red as Dexron 3. From what I read 2005-6 years with over 60K miles are worst. Nissan is not accepting responsibility or even notifying owners of this problem so they can replace these defective radiators before incurring a $5,000 repair. The local Nissan dealer service manager also denied there is a problem, however, he recomended an aftermarket radiator rather than replacement with a Nissan factory part. If you own one of these vehicles check it out.
