There are more than a few old trucks still out there waiting for a good home and a new lease on life, but many of these trucks have had their ride and safety sacrificed for looks. While there are a great number of people who love a truck that is sitting in the weeds, the work done to get it there needs to be well thought out or you and your truck might literally wind up "in" the weeds.
It's easy to cut or remove a bunch of leaf springs and mess with the shackles to try and lower a truck, but they were put there for a reason at the factory and designed to work with all these parts intact. Once you start removing suspension parts, you jeopardize the ride and safety of you and others. This is why there are lowered suspension parts available in the aftermarket.
For those not wanting to get into doing framework or installing airbags on their '55-59 Chevy truck, you have a couple of choices: using a dropped axle, dropped leaf springs, or dropped monoleaf springs. Of course the first can be used with either of the latter to get the nose really down.
 Here is the heart of the leaf...  Here is the heart of the leaf spring upgrade we are doing on a '55 Chevy truck, 3- and 6-inch dropped monoleafs from Performance Online-aka POL. This truck, like so many out there, has already been lowered for looks somewhere along the way-not for function, let alone safety! We're looking to right some common lowering wrongs. |  While we're at it, we'll be...  While we're at it, we'll be replacing all of the leaf spring pins and hardware that make up the shackles and mount the springs to the chassis. POL sells replacement stock pieces like these for both the front and the rear leaf springs on '55-59 Chevy 3100 trucks. |  Here is the truck in the beginning....  Here is the truck in the beginning. It was bought by Circle City Hot Rods (CCHR) in Orange, California, to use as shop truck, but it was quickly decided that the ride was scary in more than a few ways, including literally. The truck had a good stance and already had a dropped axle in it, but that's where the good ended. |
In the rear there are a few options as well. There are long shackle kits, flip kits to mount the rearend on top of the leaf springs, and dropped leaf spring packs as well as monoleafs. An easy way to drop the rear of a truck 4 inches with the rearend mounted below the leaf springs is to use a flip kit, but sometimes C-notching the frame is necessary.
Well, what if you have a truck and you're not sure what has been done to the suspension? You know it's low, but underneath it looks dangerous, not to mention it rides bad. That's just what we encountered when we talked to Circle City Hot Rods in Orange, California, about a '55 Chevy 3100 they bought to use as a shop truck. It sat nice and low, had some cool old ET five spokes on it, and ran well, but when we went for a ride in it, we knew immediately something had to be done!
A few things were obvious: it already had a dropped axle, many leafs (front and rear) had been removed as well as cut, it was basically riding on the bumpstops, and the rearend had been flipped and swapped to a 10 bolt. We didn't even realize at the time that the rear shackles had been flipped down to compensate for lowering it too much in the back. This raised it back up 6 inches, but also locked the shackles from swinging like they are supposed to.
 A peak under the frontend...  A peak under the frontend and we see a leaf spring pack missing more than a few leafs and what's left was cut up and had no arch to speak of. |  After taking a few ride height...  After taking a few ride height measurements, CCHR and truck owner Jimmy White pulled out the dropped axle and brake assembly for a better look at the springs. Don't forget your jackstands! |  The front shackles need to...  The front shackles need to come apart so the springs can come out. There are nuts on the end of each threaded pin that go in the spring eye and the threaded bushing in the chassis. Support the spring pack, remove the nuts, the sides of the shackles, and lower the spring pack. |
So a call was made to Performance Online to see what to do about the desperate situation. They recommended their dropped monoleafs for the front and rear and corresponding spring pin and shackle kits. Fore the front they have a 3-inch dropped monoleaf kit and out back there is either a 4- or 6-inch dropped pair of monoleafs. We were hoping to keep the ride height close to where it was to start with, but we weren't sure exactly how much it had been lowered so we went with the 3- and 6-inch monoleafs (remember this truck already has a dropped axle).
The rebuild of the stock spring pins and shackles is pretty straightforward once the old parts are out; just grease everything up and put the new monoleafs in. The 6-inch monos proved to be too much drop with the rear axle already being flipped, so we re-flipped it back below the leafs like it would be stock, using Performance Online's rearend flip kit. This allowed the use of the 6-inch monoleafs with a 1-inch block to give the truck the look, ride, and rearend clearance.
In the end, the truck came down another 1/2-inch in the front and a full inch in the rear from where it started! Plus the ride is much better and of course safer. Performance Online has just about everything you need for the underside of your classic Chevy or Ford truck-check them out today.
 Using one of the old pins,...  Using one of the old pins, thread it back in from the inside of the frame and use a hammer to drive it and the threaded bushing out of the frame. You can see the bushing starting to come out here. |  Clean up the hole and using...  Clean up the hole and using the same old pin, thread it into a new threaded bushing. Grease the bushing and carefully start and drive the new bushing into the frame. |  With the new bushing installed...  With the new bushing installed flush in the frame, grease up a new threaded pin and thread it into the bushing so an equal amount is sticking out on both sides. |
 The monoleafs came with new...  The monoleafs came with new threaded bushings in the spring eyes, so grease them and thread in a pin. Slide a rubber seal on each side of each pin, so a total of four on the front shackle as seen here between the shackle plates. Lift the monoleaf into place and slide on the shackle plates followed by the locking nuts and new grease zerks. Alternate tightening each nut while making sure the threaded pins don't spin in or out. |  We noticed that the caster...  We noticed that the caster on the axle in the truck was a little on the positive side, so we also ordered some of POL's caster shims. These will help lay the axle back a bit and should make the steering more stable. The little spacers sit in the slotted grooves; you'll want to make sure they don't sit higher than the shims so the axle, shim, and spring seat properly. |  Here we see the shim between...  Here we see the shim between the axle and the monoleaf with the thicker side to the rear. The POL monoleafs came with new U-bolts, which were used to tighten the assembly back down. We now have about 4 degrees of caster. There is a simple machined pin and a nut that mount the rear of the front monoleafs to their brackets on the frame; don't forget the grease during assembly and to use the grease gun on all the zerks afterward. |