Lubricating Leaf Springs
I just viewed a process for lubricating leaf springs on the DIY Network, a cable station literally for Do It Yourselfers. It looks promising.
Clean all rust from all surfaces of the leaf springs while it is on the car. Blow off or dust off the “rust dust” and paint the spring(s) with an appropriate under car paint. Let the paint dry for a day or two.
Using a good quality bearing grease, smear the grease over all surfaces of the spring that lie between the axle clamps and the shackles.
Using duct tape, wrap the spring from the axle clamps to the shackles making a sleeve that will temporarily contain the grease and allow it to work its way between the leafs of the spring without attracting dirt and other road grime.
Drive the car for a couple weeks worth of good driving prior to removing the tape and thoroughly cleaning the spring(s) of excess grease. If you do not drive your car much, it may take longer to work the grease between the leafs of the spring(s).
This process will allow the spring to work properly & smoothly and vastly improve the ride of the vehicle.