You need to watch the steering linkage and suspension parts on Frontiers and Xterras. When they get worn or broken, your tires will wear faster, your ride won't be good, and your fuel costs will go up. To judge how well your shock absorbers or struts work, park your vehicle on a flat surface, shut off the engine, engage the parking brake, check the tires' pressure before starting. Press on one side of the vehicle and watch how it comes back down. If it keeps moving instead of stopping and bouncing back down, you may need new shock absorbers or struts. Use jackstands to lift your vehicle safely. Inspect the shock absorbers and struts while the car is on stands. Look for leaks into the fluid and make sure both parts are well-attached and working correctly. If you find any damage, replace the entire system as one unit. When checking the steering and suspension system, look closely for problems where control arms meet at the bushings and steering gear. There should be no liquid leaks around this area. Clean the area below the steering knuckle. Have a helper move the tire back and forth while you watch for movement at the balljoint. Changing the balljoint is needed if you see movement. Squeeze the outer edges of each front tire. Look for play in any moving parts of the steering system while checking for worn idler arm and tie-rod ends. Every 4WD model should get checked: look for breaks or tears in CV Boot, and replace them when you see loose attachments or signs of lubricant leak.