Rear Spring Pivot Bolt, 1947-1963, Willys Pick Up Truck

This kit was the 2” lifted version over stock. I’m glad I got the entire kit of shackles and fasteners. The 70 year old stock suspension was terribly worn. You don’t realize how badly an old suspension has deteriorated until you take it apart. Bolts are bottle necked. Shackle and spring eyes are egged out. The K factor in the springs is gone resulting in a nasty shackle slap on rough ground.

The new set up is assembled with a lot of white grease, anti seize, and bearing grease. These are grease systems in which the shackle chambers are pumped up (hence the zeros). Everything is hand tightened with a torque wrench. 59 ft-lb on spring bolts. 27 ft-lb on rear shackles and the back pivot for the front sets. Front shackles on the front set are carefully drawn together keeping an eye on the spacing. Avoid over tightening! The shackles have to swing freely for the system to operate!

The truck height improved dramatically. I added a stock GM spacer to raise the rear axle to lower the rear end (axle is on top of the spring). This helped to level the overall stance and bring the rear differential pivot angle back to 6 degrees.

The new front springs tilted the front axle which corrected its differtial pivot angle. Previously the front propeller shaft was running too linear for the U joints to operate properly. The front axle to new springs set up also corrected the pitch to camber ratio with the solid king pin alignment. I dialed the toe in to spec (nearly straight). Now the truck steers much easier and tracks straight down the road without touching the steering wheel.

I’m going to experiment with some Bilstein 5100 shocks to determine if their valving can suppress rebound on a spring bounce. The Monroe shocks that came with the kit install easily and are soft.

I have a large tractor weight and collection of sand tubes in the bed to help break in the rear springs. The bounce on a new set has some bight to it. I can feel the bounce bight soften as I keep running up and down rough roads. Platte County, Missouri has no shortage of rough roads.

I haven't installed the bolt yet but it appears to be of excellent quality. I was somewhat surprised that a new grease fitting wasn't installed or included with the bolt. I have been pleased with all the Jeepsterman products I have purchased.