It's a good time to be a mini-trucker. Back in the day, finding specialized parts to 'bag your mini was tough, and locating parts that fit correctly was an even greater chore. These days, we have it easy. Parts are everywhere, and contacting the advertisers within the pages of Mini Truckin' will yield a multitude of choices for 'bags, valves, mounting brackets, fittings, and everything else you'll need to lay out your favorite mini.
This month, we'll begin detailing the process of installing an airbag suspension in a '91 Nissan Hardbody. The process is nearly identical for all torsion-bar-equipped mini-trucks, but this guide will specifically help those of you who own '86.5 to '97.5 Nissan mini-trucks. This time around, we'll be working on the front suspension using parts obtained from Chassis Tech and Thorbecke Fabrication, and our favorite local fabricators from IMZZ Industries will be performing the mods. The frontend will receive a new set of Chassis Tech 2-inch drop spindles and universal, trim-to-fit mounting brackets from Thorbecke Fabrication. The spindles will automatically give our Hardbody a 2-inch drop, which means we won't have to put the front suspension in such a radical bind to get the truck all the way down on the ground. This will make the upper ball joints last much longer than if we attempted to lay the frontend of the truck out without using the drop spindles. The universal 'bag brackets represent the latest in laser-cut steel technology. They are oversized and can easily trimmed with a bandsaw or another device to provide a perfect fit for your mini-truck.
That said, we'll get on with the install. Check back next month as we lay out the rearend of the Hardbody and finish up with the plumbing and wiring. For more information, contact the companies listed in the source box.
1.We began by removing all...
1.We began by removing all of the new suspension parts from their respective packaging and laying them out. We'll be using 2,500-pound 'bags, and as you can see, the super-clean universal brackets include all the necessary gussetts and shock relocation brackets.
2.All Nissan Hardbody pickups...
2.All Nissan Hardbody pickups use the tried-and-true, unequal length upper and lower control arm suspension design with torsion bars to carry the weight of the truck.
3.James not only owns IMZZ...
3.James not only owns IMZZ Industries, he's also the head fabricator of the shop. He began the install by unbolting the torsion bar adjustment bolts.
4.Moving toward the middle...
4.Moving toward the middle of the truck, James removes the retaining clips using a flat-blade screwdriver.
5.The front of the torsion...
5.The front of the torsion bars slides into a splined pivot arm that is bolted to the control arm. These bolts are also removed with the impact gun and 14mm socket, and then the bars are taken out of chassis from the rear of the truck. The bars will not be reinstalled, so they can be tossed aside or sold to the kid down the street.
6.Disassembling the front...
6.Disassembling the front suspension is a pretty easy task. After removing all of the cotter pins from the castle nuts, the outer tie-rod ends are unbolted from the spindles. Then the upper and lower ball joints are unbolted from the spindles. The nuts are left in place while a dead-blow hammer is used to knock the ball joints free from the spindles.
7.Next, the old shocks are...
7.Next, the old shocks are unbolted. Hardbody trucks have a stud-type upper shock mount that affixes the shock with a single nut and a bushing-type lower mount. Once the nuts and bolts are out, the shocks are removed from the suspension and thrown away.
8.These nifty brake line clamps...
8.These nifty brake line clamps from Snap On Tools are a great way to pinch the brake lines closed and prevent fluid from leaking out of the lines after they are unbolted from the spindles.
9.After the brake lines are...
9.After the brake lines are removed, the castle nuts are take off, and the spindles, hubs, rotors, and brake calipers are removed in two separate units.
10.The next step is to unbolt...
10.The next step is to unbolt and remove the upper control arms so we can gain access to the factory bumpstop mounts.
11.The bumpstop mounts are...
11.The bumpstop mounts are cut from the framerails to make room for the new 'bag mounts.
12.See that big hole where...
12.See that big hole where the bumpstop mount used to be? We'll be plating it with steel to retain the integrity of the framerail.
13.To clean up the areas that...
13.To clean up the areas that were cut, James grinds the steel smooth using a 4-inch angle grinder. Note that James takes the issue of safety seriously and is wearing his mom's hat to protect his dome from the sparks!
14.A cardboard template of...
14.A cardboard template of the hole is made and then transferred to a sheet of 1/8-inch thick, cold-rolled steel. The patch piece is then cut using a vertical bandsaw.
15.The patch piece is then...
15.The patch piece is then MIG-welded in place, and James pats himself on the back for laying down the super-clean bead.
16.It's now time to prep-fit...
16.It's now time to prep-fit the upper 'bag mounts. To do so, the suspension is reassembled and pushed to full "bump" by placing a transmission jackstand beneath the lower control arm. We plan on installing 215/35ZR18 tires after this truck is 'bagged, and because we know our tires will measure approximately 24 inches in diameter, we bumped the suspension upward until our imaginary tire line was even with the bottom of the framerail. This equaled the position of the suspension when the truck would be laid out on the 18s. We then compressed an airbag to determine the upper 'bag mounts' best possible mounting location.
17.The mounts were then trimmed...
17.The mounts were then trimmed on the bandsaw and MIG-welded in place.
18.Gussetts are provided in...
18.Gussetts are provided in the kit and should definitely be installed. That is, unless you actually want to see your upper 'bag mounts bend in half and tear off of the framerails later on. Again, these parts are universal, so we trimmed them prior to installation.
19. Moving down to the lower...
19. Moving down to the lower control arm, the stock shock mount is cut off using the plasma cutter in preparation for the new lower 'bag mount.
20. The control arm is plated,...
20. The control arm is plated, and once the position of the 'bags are marked, the suspension is disassembled and the lower 'bag mounts are drilled out.
21.The 'bags are then reinstalled...
21.The 'bags are then reinstalled using the hardware provided. The top stud mounts received a pair of lock washers, 1/2-inch nuts, and a 1/2-inch air line fitting. The bottom of the 'bags were attached using 1/2-inch bolts and flat washers.
22.It was then time to install...
22.It was then time to install the new drop spindles. These cast spindles from Chassis Tech are nearly indestructible and will add another 2 inches of drop to the front wheels of our project truck.
23.The stock spindles were...
23.The stock spindles were swapped out for the new drop spindles, and then the new shock mounts were welded onto the framerails.
24.The rest of the suspension...
24.The rest of the suspension was put together, and then the truck was rolled out of the shop. Some temporary air fittings allowed us to lay out the truck and check our progress.
25.She looks good, but she'll...
25.She looks good, but she'll look even better after we relocate everything in the engine compartment and cut out the factory inner fenders. Stay tuned for Part II of this story in the next issue of MT.