Lubrication

Ford manual-style steering boxes (those that do not have power steering fluid running through them), use a grease internally as a lubricant - not a fluid. This grease is a moly or lithium-based grease like used in lubricating the suspension and steering linkage. It is thick enough to cling to the internal pieces as they move but soft enough to flow through the box also. The steering box's location near the exhaust manifold and engine also causes the grease to soften and move freely. A liquid lubricant would settle to the bottom of the casing and leak out the bottom seal.

The inside of the steering box needs to be as fully packed with grease as possible with very little air pockets. As the rack block moves up and down the input shaft, and the sector shaft teeth move across the rack, they should push the grease back and forth inside the box, constantly redistributing the grease and keeping the parts covered at all times. An insufficiently filled steering box will not have enough grease in it to flow around and the parts will only have what grease clings to them for lubrication. Soon this grease will wear off and the parts will be rubbing metal to metal. It is not really possible to overfill a steering box with grease if it is vented somehow. Boxes with long input shafts have no seal where the shaft goes in and excess grease will find its way out there. Short input shaft boxes have fill plugs with venting and excess grease will be forced out there. Grease coming out of the box in these areas is not a sign of problems - it is just venting excess grease and will stop when equalized.

Ford used a moly-based grease inside the steering box. It lubricates the mechanical actions of the box well, is thick enough to cling to parts without running off and settling to the bottom, and is soft enough to flow back and forth inside the box by the pumping action of the rack block and sector teeth. Heat from the exhaust manifold and engine will soften it on cold days and yet the grease stays thick enough not to liquify and seep out of the bottom seal. A good moly or lithium based chassis grease will work in this situation and is easy to find in tubes and install using a common cartridge-style grease gun.

Do not use a liquid lubricant (such as 90w axle fluid) in a steering box. Liquid lubricants will settle in the box and not lubricate the upper portions of the gears. It will also seep through the bearings and leak out the bottom seal. Do not use wheel bearing grease inside the box. Wheel bearing grease is too thick to coat and work properly. Wheel bearing grease is designed for the high heat enviroment of the brake system and does not soften with heat and will not flow through the box like a moly-based chassis lubricant will.

Adding lubricant to a steering box will not help if the box is already damaged or worn inside. A steering box that has excessive play that cannot be adjusted out, rough or ratchety action when turning, or binding will not be cured by lubrication. Installing a heavier grease or a lighter oil will not help. Lubrication is designed to prevent wear and corrosion on parts in good condition and will not compensate for damage or wear caused by prior insufficient lubrication, rust corrosion or improper bearing settings and adjustments.