Chevy Dumpbed Pickup Truck - Project Reject

With lots of more-or-less pressing mechanical issues to deal with, we had hoped to have most of them licked before doing this dump-bed conversion, but we had also promised the boss to have the Pierce Sales kit installed for this issue. So, consider this a separate gig from the project as a whole for now, and next time we'll get back to the trials and tribulations of wrenching on the retired Navy pickup itself.

A pickup with a dump bed is... 

   

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A pickup with a dump bed is not quite the same as a real dump truck, but while the truck excels in hauling 10 yards of dirt over a longer distance, the little pickup can get its smaller loads into places a dump truck couldn't even get near. Also, there is a significant difference in price and overall practicality between the two. If you can't afford the real thing, or don't want a 10-wheeler sitting in the driveway, consider converting your pickup.

Many tasks are elegantly handled by the utilitarian nature of a pickup, and a 4x4 version can be even more multitalented. But they aren't perfect. Fully capable of hauling dirt, rock, and gravel, for example, a pickup fails miserably when it's time to unload such cargo. Using a shovel is the common and back-breaking method. Or, you can try backing partway down a slope with the tailgate open, and hope that the load goes down and that the vehicle doesn't. But, if the slope is steep enough to empty the bed, it's probably also too steep to drive back up.

A far more elegant solution is to install a dump-bed conversion kit, such as the 2-ton Universal Dump Kit from Pierce Sales shown here. Not only does it make it practically effortless to unload the bed in about 10 seconds, the pickup still looks and functions just like it used to, but with the added feature of lifting the front of the bed. Basically, pivot points are created at the rear of the bed, and a hydraulic ram is used to lift the front. A dash-mounted three-way switch energizes the motor for the hydraulics when pushed up, lifting the bed. It keeps the bed in its position (up, down, or in between) when in the middle "neutral" spot, and then lowers it when the switch is pushed downward.

Considering that the P046-UK kit we used fits most Dodge, Ford, and GM pickups, and a wide span of model years from the '70s on up, it was surprisingly simple to install. Everything fit and functioned as intended, with the exception of the instructions. Vague and often cryptic, we had numerous "Uh ... " and "How was that supposed to be again?" moments as we leafed back and forth in search of more definitive answers in the instructions. Still, the installation is simple enough that the job can be finished over a weekend with time to spare. We have included quite a few photos, which will hopefully help clarify the process should you decide to increase the usefulness of your pickup.

1. These are the parts that...        read full caption 1. These are the parts that came with the $940 Pierce Sales kit (PN P046-UK), which is one of 11 kits available. To the left are the "scissors" with the hydraulic cylinder, and directly below is its frame mount. The electric motor, pump, and reservoir assembly are in the center, surrounded by the various brackets, parts, and hardware included in the kit. You'll see most of those pieces in later photos.	2. This is really the end...        read full caption 2. This is really the end result of the installation, but by showing the completed setup, it may be easier to follow the steps it took to get to this point. Notice how the system uses a crossmember on the frame for the lower attachment, and how the force from the hydraulic cylinder is spread by the large mount on the bed. At full lift, the bed tilts to 38 degrees in this case.	3. Removing the bed is relatively...        read full caption 3. Removing the bed is relatively straightforward-just make sure you disconnect everything, including ground wiring and the vent hose for the axle. Getting the nuts off the eight carriage bolts that hold the bed to the frame with an impact wrench did not work well. A ratchet wrench does a better job on the long bolts and also prevents rounding off the holes in the bed's sheetmetal. A few friends, a sturdy tree branch, or a tractor bucket, is then needed to lift the bed off. Remove the bumper next.
4. Installing the hinge plates...        read full caption 4. Installing the hinge plates and arms is the most time-consuming part of the job, largely because of the less-than-clear instructions. Since it involves cutting material off the frame, it's also a step that is better done right the first time. We followed the second set of instructions at the very back (yes, there are two versions) and marked the areas to be removed using the hinge arms as templates instead of whacking off a big chunk of frame.	5. A partial hole needs to...        read full caption 5. A partial hole needs to be cut in the rear of the frame and holes drilled to match the hinge bracket's mounting holes. With six holes in the frame already in this small area, we opted to drill through the bracket instead for three of the four holes.	6. Install the hinge arm on...        read full caption 6. Install the hinge arm on the plate and check for clearances, and that the hole in the horizontal part of the arm ends up where it should, right where the factory hole for the bed bolt was. Don't skimp on this step or the bed will end up crooked.
7. This is how the installed...        read full caption 7. This is how the installed hinge bracket should look when it's all bolted down. It would be wise to double-check the distances, just to be sure.	8. A stiffener plate and the...        read full caption 8. A stiffener plate and the lower mount for the hydraulics is mounted below the crossmember. This is where we ran into clearance issues with the diesel-only dual exhaust, which in this case was a funky muffler-shop setup. After cutting the mufflers and exhaust pipes off, there was plenty of room, and we have wanted to make the pipes come out ahead of the tires anyway. On most pickups, this wouldn't have been a problem.	9. Mounting the "scissors"...        read full caption 9. Mounting the "scissors" to the lower mount is by a rod held with cotter pins. We didn't have any 1-inch washers (which we feel are essential to keep the cotter pins alive), so the cotter pins were barely bent for now. There is a "scissor support cable" that's supposed to go in between the framerails to hold the back of the scissors up, but we used wood blocks on the axlehousing instead since the brake proportioning bracket prevented putting the cable where it was supposed to be. Actually, we have yet to figure out the real purpose of that cable.
10. Next on the list is to...        read full caption 10. Next on the list is to mount the pump assembly and to run the hose between the pump and hydraulic cylinder. We would've preferred an inside-the-frame position but ended up putting it outside after all. Do make sure the bed clears everything in the down position.	11. With the pump assembly...        read full caption 11. With the pump assembly installed on the frame, the solenoid for the downward movement must be partially removed to install a 90-degree fitting onto the pump. Remove only the top portion as shown and the fitting will just clear. Install the pressure hose between the fitting and the hydraulic cylinder. Add three quarts of Dextron III ATF to the reservoir.	12. This is the pump assembly...        read full caption 12. This is the pump assembly installed, but not yet wired. Notice the rubber hose used to protect the high-pressure hose from abrasion where it passes through the frame. The rest of the hose was secured with wire ties. Wiring the (up and down) solenoids is straightforward, using the included 20-foot four-gauge welding cable and the secondary wiring for the dash-mounted switch. As with the pressure hose, be sure to keep the wiring secure to keep it from rubbing through the insulation over time.
13. It is now time to mount...        read full caption 13. It is now time to mount the hinge arms to the bed and put the bed back on. We put the bed on first and used a piece of 4x4 to keep the rear of it up while bolting on the hinge arms with a pair of 5/8-inch bolts. Then the bed needs to be lowered and positioned so that the original bed bolts go into the holes in the hinge arms, here shown being tightened. Next, the bed is supposed to be lifted up. We raised it using the hydraulics, with a piece of plywood between the bed and the scissors.	14. The forward end of the...        read full caption 14. The forward end of the hinge arms is then bolted to the bottom of the bed. There are a series of holes in the hinge arms, but none quite matched the bed's layout so we drilled new ones. Still, it's amazing how much does bolt up with such a generic kit.	15. Since we worked alone,...        read full caption 15. Since we worked alone, we bolted the "clips" that the upper rod goes through onto the upper mount and let the hydraulics hold the mount in place while we drilled the needed mounting holes in the bed. Yes, we used a 4x4 as a safety prop, and yes, we misunderstood the instructions and put the clips way too far back at first. This is supposedly the correct position for a Ford. Either way, this step largely concluded the installation. There are still minor things like rubber bumpstops, guides for the bed (to keep it positioned side-to-side up front), dealing with the fuel filler, and other details to finish, but most vary a lot from vehicle to vehicle, just like the wiring layout would. One bigger item is the rear bumper. We weren't going to use one but if you are, Pierce Sales suggests welding it to the hinge arms as there are so many variables. All in all, it sure wasn't bad for making a pickup that much more practical by installing a dump-bed conversion.