Infiniti FX45 2003-2008 Drivetrain Specifications

The 2003-2008 Infiniti FX45 features a full-time all-wheel-drive (AWD) system paired with a 4.5L V8 engine producing 315 horsepower and 329 lb-ft of torque. The drivetrain includes a 5-speed automatic transmission with manual shift mode. The AWD system automatically distributes torque between the front and rear axles for optimal traction. This setup is compatible with 18-inch or 20-inch wheels, depending on the trim level.

Regular maintenance for the FX45 drivetrain includes checking and replacing the transfer case fluid every 30,000 miles, inspecting the driveshaft and CV joints for wear, and ensuring the AWD system is functioning properly. The differential fluid should be replaced every 60,000 miles. Additionally, inspect the transmission fluid and replace it every 60,000-100,000 miles, depending on driving conditions.

To replace the FX45 drivetrain components, first, lift the vehicle securely on a jack stand. For the driveshaft, remove the bolts connecting it to the differential and transmission. For the transfer case, drain the fluid, disconnect the driveshaft, and unbolt the case. For the differential, remove the axles, drain the fluid, and unbolt the housing. Always refer to the service manual for torque specifications and proper alignment.

Common drivetrain issues in the FX45 include AWD system malfunctions, often caused by faulty sensors or a worn transfer case. Vibrations during acceleration may indicate a worn driveshaft or CV joints. Unusual noises from the differential could signal low fluid levels or worn gears. Diagnose issues by scanning for error codes, inspecting components for wear, and testing the AWD system's functionality.

To optimize the FX45 drivetrain performance, ensure all fluids are at the correct levels and use high-quality synthetic oils. Regularly inspect and replace worn components like CV joints and driveshafts. Upgrade to performance tires for better traction. Consider installing a performance air intake and exhaust system to improve engine efficiency, which indirectly benefits the drivetrain.