Owners of some Nissan trucks and sport utility vehicles (SUV) are urging the National Highway Traffic Safety Administration (NHTSA) to open an investigation for transmission problems. Reports filed with the NHTSA alleged that an internal crack on the oil cooler tube in some Pathfinders, Frontiers and Xterras, could force coolant into the transmission causing transmission failure. Last October, Nissan extended the warranty on radiators of 2005-2010 Frontiers, Pathfinders, and Exterras to eight years or 80, 000 miles, but under the extended warranty, Nissan did not have to cover vehicles bought used. Owners feel that Nissan extended the warranty on these vehicles, knowing they would surpass 80,000 miles before having problems with the transmission. They want Nissan to issue a recall to all owners and reimburse those who have already paid for transmission repairs.