(Note: When we announced that our new expedition vehicle was to be a Toyota Tacoma, a forum member obviously expecting something more exotic and expensive posted, "Oh—it's just a Tacoma." And that immediately became the nickname for the new vehicle: Just A Tacoma and Camper. More images of the setup are on our Flickr pages.)
As I mentioned in this piece, the suspension on our 2012 Tacoma was ridiculously stiff from the factory. Nevertheless, adding a 750-pound-plus camper called for some sort of modifications to maintain a level ride height and provide adequate roll control while retaining as much compliance as possible. There are really only two ways to do this properly—substituting heavier rear leaf springs, or augmenting the stock springs with adjustable air bags, in effect adding an auxiliary spring. (I’ll discuss shock absorbers in another article.)
A third approach is to insert an “add-a-leaf”—a single extra spring leaf designed to increase the rate of the spring and raise the ride height. But our experience with these—and the experiences of several people we know—has been unfailingly poor. The problem is that the extra leaf is rarely matched properly in rate and shape to the existing spring pack, and ends up exerting and experiencing excess pressure. (This is particularly true when an add-a-leaf is used in an attempt to rejuvenate a tired spring pack.) We’ve broken two add-a-leafs (slow learners), and know of at least a half-dozen others.
A properly designed complete replacement spring pack works very well to accomplish the task, and in fact Tom Hanagan, the owner of Four Wheel Campers, took this approach with his own Tacoma. However, in both the previous trucks on which we mounted our first FWC, we left the stock springs in place and installed adjustable air bags to carry the extra load. This worked extremely well for us, with the notable exception of a faulty spring bracket on an Air Lift kit we used on the 2000 Tacoma, which walked free of its mount.
To my mind, advantages of the air bags are several. First and most obvious is the adjustability. The weight of the camper can vary by several hundred pounds depending on whether it’s empty or loaded for a month-long trip. With the air bags you can compensate perfectly. Also, the bags essentially comprise an entire backup spring in the event of trouble with the main pack. If you break a leaf on the stock spring somewhere far from home, you can simply remove the leaf and add more air to the bag on that side.
Although it’s a secondary consideration for me, an air bag kit is less expensive than a set of custom springs, and easier to install as well. Finally, if the air bag kit is equipped with a compressor and independent in-cab control for each side, you can use the bags to level the vehicle when camping—both front to rear and side to side.
Although we never had trouble with the actual bags of the Air Lift kit, I wanted something a little more heavy duty for this truck—and fortuitously got an email at exactly the right time from Reece Tasker of Canadian Suspension Importers. CSI handles the Boss system from Australia, and a brief look at the specs convinced me this was the kit to try. The Boss air bag, with a working range of around 15 to 150 psi, is tested to seven hundred fifty psi. That seems like reasonable safety margin to me.
Reece moved a couple of mountains to have a kit delivered to the FWC factory in time for me to install the kit before we left with the new camper. I was impressed with the bags, and just as impressed with the high-quality compressor and in-cab control kit/gauge combination. All the air line and every fitting I needed was included.
This configuration requires drilling two holes in the frame above each axle, which I was able to do with a sidewinder drill by jacking up the truck until the rear wheels were just loaded enough to keep the axle in place while I marked and bored the upper holes, then loosened the U-bolts to each spring and inserted the lower mounting bracket. (Reece plans a bolt-on kit requiring no drilling, but I didn’t find it a chore.) I didn’t have time to install the compressor and control kit, and simply connected both air lines to the manual-fill valves also in the kit.
The Firestone air bag kit I had been considering mounts in such a way as to preclude the fitting of larger-diameter rear shock absorbers. I was pleased to see that the Boss kit introduced no such restriction, so the Icon shocks we'll be adding should slot right into position.
With the camper in place, a quick jet of shop air into each bag raised the truck to a perfectly level stance. On the leisurely 900-mile drive home (two camps and, er, one hot shower each in the FWC’s cunning shower stall) I didn’t have to add air once. The only change I’ll make so far is to add a right-angle air line fitting at the bag—currently the line has to curve down almost below the axle to avoid crimping before traveling up through the frame.
I’ll report further after installing the control kit, and a trip into the Sierra Madre in Mexico to retrieve some trail cameras we have set up there to survey the mammal population (an assistance project of our charity, ConserVentures, for the southwestern conservation organization Sky Island Alliance).