Lubricating the chassis and suspension every 15,000 miles helps preserve your car's ride and handling. To locate the grease points, check your vehicle's service manual. A car may have as many as 10 or 20 different grease points.
If the manufacturer has installed plugs in the suspension where grease fittings should be, you can purchase grease fittings and install them yourself. You can also purchase hand-operated grease guns in auto parts stores.
Be sure to grease the Zerk fittings in the upper and lower ball joints. (If they are covered with a layer of dirt, you should clean them off before pumping in the lube.) Pump in the grease until you can see the boot swell, but don't overfill to the point of bursting.
In your Fall/Winter checkup, give all rubber hoses, fittings, seals and insulated wire a coat of silicone lubricant to keep them pliable. In the Springtime, wipe away any excess lube to prevent dust contamination.
Examine all suspension joints and tighten all chassis bolts, using the proper wrench. Check the ball joints for wear, which is simplified if manufacturers have installed wear-indicator ball joints. While the car rests on the ground, check the ball-joint wear collar that surrounds the grease fitting on the lower surface of the joint. If the collar descends below the joint surface, the joint is worn and must be replaced. On some types of wear indicators typically found on some Chryslers, you try to wiggle the grease fitting to see if it moves, in which case the joint is worn and should be replaced. For cars without wear indicator joints, check the vehicle's service manual in order to find the correct diagnostic procedure.