TORRANCE, Calif.--American Honda Motor Co., Inc. announced today in a statement that it will expand its existing voluntary recall of light truck models for a potential transmission defect to include certain Honda and Acura passenger cars. The voluntary action involves approximately 499,000 Honda and Acura passenger vehicles with V6 engines and 5-speed automatic transmissions. Affected models include certain 2003 and early 2004 model Accord V6 sedans and coupes, 2000-2003 and early 2004 Acura TL sedans, and 2001-2003 Acura CL coupes.The inspections and repairs will cost Honda about $63 million, in addition to the $153 million being spent on the light-truck portion of the recall, spokesman Andy Boyd said. In Japan, Honda is spending about $8.5 million on its recall.The company has found only one confirmed instance of a transmission failure related to this defect in its passenger cars, with no accidents or injuries. "We are acting out of an abundance of caution to ensure that this doesn't become an issue for our customers," said Tom Elliott, executive vice president of American Honda Motor Co., Inc. The situation is created by insufficient lubrication of the transmission's secondary shaft second gear that can occur under certain driving conditions. Prolonged operation under these conditions can lead to heat build-up and under certain circumstances may eventually result in chipped or broken gear teeth or breakage of the gear. In the event of a chipped or broken tooth, the owner will likely experience abnormal noise from the transmission and seek repairs. In rare instances, this condition may lead to gear breakage and possible locking of the vehicle's transmission, creating a potential safety hazard. Owners of affected vehicles will be contacted via mail and will be asked to take their vehicle to an authorized Honda or Acura dealer to be repaired free of charge. Customer mailings will begin in late July. In most cases, the repair involves a simple gear inspection, which is accomplished without removing or disassembling the transmission, and a modification to increase the flow of transmission fluid to the affected gear. If there is any indication of damage to the gear, the dealer will replace the complete transmission assembly.