1948 Willys Jeep Buildup - Project Murderous Overkill Part V

Without the engine acting as a crossmember, it was impossible to get correct measurements to build the rear suspension because the framerails were now back out of square. We put the suspension on hold for a weekend while we built a full interior cage of 1 3/4-inch, 0.120-wall DOM tied solidly to the frame. Eventually, the cage will extend forward through the engine compartment and back into the bed, but that'll come later.

Once we put five 100-pound sand bags on the front to simulate an engine, we discovered the rear was going to be way too high if we used the regular M.O.R.E. spring hangers. Rather than exchanging our pieces for the company's stubby versions that we used in the front, we cut and welded the standard hangers to lower the rear.

With the hangers built, we measured the centerline of the hangers and the frame in several places. Then we drew a line through our measurements and eyeballed the hanger onto the frame. Once tack welded, we installed the rear spring and rotated it up to make sure it contacted the frame in the center. You need to take a little time to ensure the hangers are square so the spring bushings don't bind and get chewed up as the suspension cycles.

The cage alleviated some of the flex, but we could still grab the forward framehorn and severely tweak the frame out of shape. These pickups have five factory crossmembers, not counting the tranny/T-case crossmember. We found our No. 3 and No. 4 crossmembers were totally rusted through, so we built new ones out of some 2x3-inch, 0.120-wall rectangular tubing. The new pieces did the trick, making the frame totally solid.

For the rear shackle hangers, we determined where we wanted the shackles to hang with the springs at full droop and used a 1 3/4-inch hole saw to buzz through the boxed frame. Then we cut a piece of 1 3/4-inch, 0.120-wall DOM tubing and slid in some 1.5-inch diameter Wrangler spring bushings. We assembled the shackles on the spring, then tacked the tube to the frame before pulling it apart and welding it up.

For the rear springs, we ordered some 52-inch Rancho springs (PN RS86209) intended for the rear of a fullsize Chevy. We removed the overload spring and flipped the centerpin, then mounted them to our 14-bolt using Dynatrac's high-clearance U-bolt kit.

The 4-inch lift RS86209 springs have a light 287 lb-in spring rate, which settled a bit more than we were expecting. However, once we add the drivetrain and a winch to the front of the vehicle, we're expecting the stance to even out. If we need to, we'll fine tune the suspension height with some longer shackles on the front or rear, as needed. We also discovered the bed floor we thought was diamond-plate aluminum is actually a 4x8-foot sheet of 3/16-inch galvanized steel, so replacing it with expanded steel will probably shave 400 pounds from the bed.