Most cars have spring-loaded valve fittings through which grease is injected to lubricate steering and suspension joints. Lubricate all fittings at least once a year-more often if the car maker recommends it-with a name-brand, premium-quality grease.
There are two types of grease guns. The trigger type permits one-handed operation so that you can hold the nozzle of a flexible hose against a hard-to-reach fitting with your free hand. With the lever type, it is easier to build up pressure, but both hands are required for operation; to reach out-of-the way fittings, you either need a helper to hold a flexible hose, a special nozzle to lock it onto the fitting, or a rigid tube with swivel joints.
Chassis lubrication
First, find all the fittings. They are generally on the suspension ball joints and the joints of the steering linkage. Dig away any dirt around the joints and inspect the rubber boot on each joint. If it is slightly cut, clean off all dirt, and heal the cut with a coat of silicone paste (available at most auto supply stores). Allow the paste to cure, then lubricate the joint.
If the boot is badly damaged, take the car to a garage. On some cars the entire joint may need replacing, on others only the boot may need changing. If in doubt, have the joint replaced.
On an older car, you will find a plug screwed into a joint. Remove the plug with a wrench and replace it with a valve fitting. If the plug is hard to reach, the replacement should be an adjustable right-angle fitting.
Wipe each fitting clean with a rag. Then push the grease-gun nozzle firmly onto it and pump the trigger or lever slowly until you see or feel the fitting’s rubber boot swell, or until grease escapes from the fitting just below the boot. If grease escapes from between the nozzle and fitting, rather than below the boot, the fitting is probably rust frozen. Replace it.
Drive-train fittings
The universal joints on the drive shafts of most newer cars come factory sealed with grease packed in. On some older rear-drive cars, however, and on many older four-wheel drive cars, you will find grease fittings on the universal joints. You may also find fittings on a joint that has been replaced. They may be recessed and may require a needle-shaped nozzle, sold in auto supply stores. Pump grease into a universal joint fitting until the grease begins to escape from elsewhere on the joint.
Transmission and manual-clutch linkages do not have grease fittings, but they should be lubricated. Have a helper operate the transmission and manual clutch while you locate the underbody pivot points. Spray all exposed pivot points with an aerosol penetrating oil; then, with your fingers, smear a coating of grease on each joint, working it between the metal-to-metal contact surfaces.
Locate the parking-brake levers at the rear wheels. Spray the joints with penetrating oil, then smear them with grease. Spray penetrating oil on the hood hinges, hood latch, and the door and trunk hinges.