You don't have to run a 3-inch body lift and 12-inch springs to run really big tires. In fact, not running a really tall lift with big tires makes for a more stable, better-wheeling vehicle. And if we can squeeze a set of 42s under a Dodge with only 6-inch springs and sagged body bushings, then you Ford and Chevy guys with bigger wheel openings have no excuse.
Sure, there are tradeoffs to massive rubber. Bigger tires are more expensive, they usually ride rougher, they're heavier, and you've got to be willing to cut more sheetmetal than if you were running smaller tires. But if you're a fullsize guy who takes his rig off road (for real) and you've already invested in 1-ton axles, then you're missing out on a whole new realm of off-road enjoyment by sticking to smaller meats.
02. When we hung these All Pro rocker guards, we never anticipated running tires much larger than the 37s we had. The 42s tagged them good. Out came the Craftsman 9.0-amp saber saw (PN 27391) and the protruding nub was hacked off. Each of the four tire/wheel combos weighed 149 pounds.
That's where we were with our Dodge. After the installation of the Dynatrac Dana 60 front axle that appeared on our Web site (www.4wheeloffroad.com), we were letting much of its new off-road potential go unrealized. The 37-inch Boggers worked well, but they offered only 11 inches of clearance under the axles and, at 13 inches wide, didn't do much to help stability at angles. We hooked up with the big tire experts, National Tire and Wheel, who sent us a set of 42-inch Swamper TSLs and Eaton heavy-duty 161/2x93/4 chrome rims. The rims have extra-heavy-duty centers and are actually one of the few rated for use with up to 44-inch tires. National got our tires and wheels to us a week after we hung up the phone with them. No small feat considering the wheels alone are 41 pounds each.
We mounted the tires at home, hacked from the body what we thought we needed for clearance, then headed out to Johnson Valley with the saber saw and a hammer for an on-trail tire test.
Big Tires on a Fullsize
These tires belong on a fullsize. We'll never go back to small tires on this rig again.
Pro:
•Awesome increases in ground clearance
•Jaw-dropping spectator impact
•Point-and-shoot capability
•Increased stability
•Peace of mind that you won't soon be craving bigger tires
Con:
•Expense
•Rougher on-street ride
•Clearance issues
•Weight
•Increased chance of breakage
03. Once in Johnson Valley, we articulated the suspension and were amazed to see that our somewhat conservative hack job on the body looked pretty close. The backspacing on the Eaton rims is 43/4 inches. Any less and the huge lugs would mangle the rear sheetmetal at full stuff. However, we'll probably hack a bit more body and get some 31/2-inch backspacing rims because the tires tagged the front springs and steering box when the wheels turned. | 
04. A lot of metal from the front fenders and inner fenderwells had to go. It's even tougher on a Dodge because a lot of it is triple-wall and structural. We used the Craftsman saber saw along with the heavy-duty air nibbler we got from Eastwood (PN 28039) to make some space. | 
05. A B.F.H. was used to peen back the upper lip of the rear fenders to prevent any contact. We also noticed that we didn't trim enough material from the rear fenders to keep the tires safe. We hooked our Craftsman saber saw up to a buddy's Premier Power Welder and did some on-trail body butchery. |
06. With the clearance issues solved, it was time to hit the trails. The huge tires rolled over voids that would have swallowed 35s, and the massive lugs clawed and manhandled the biggest boulders. Most appreciated, though, was the increased ground clearance under the diffs. We now had 131/4 inches under the huge Dana 60s. | 
07. We used to constantly get hung up on the thick webs of the Dana 60HD rear when running 37s, but now we could take the same lines without so much as scraping bottom. We didn't get hung up on a rock once, although we put ourselves out of commission before we could get into seriously gnarly stuff. | 
08. We got a little cocky with the big tires' ability to push massive boulders around. Seems this one was pretty solidly rooted and bent our tie rod end instead of budging. Without a spare, that and a cracked steering-box mount ended our day all too early. While the big tires made our fullsize wheel like a flatfender, they also highlighted any weakness in the vehicle we still needed to address. |
Driving Impressions
On Road
Well, we removed the stereo because we couldn't hear it anymore. These are big tires and the lugs are the size of your fist. You hear each one slap the ground. We've heard they're difficult to balance, so we didn't even try with ours. We set the street pressure at 17 psi, and although they shook violently when cold, once they warmed up and the flat spots went away, we could cruise somewhat comfortably at 75 mph. We are, however, wishing we had 5.13 gears instead of 4.10s.
Off Road
It's an awesome thing to watch these tires claw, grab, and move boulders the size of armchairs in and out of their way. Since they're 16.5s and we didn't have bead-lock rims, we ran them at 11 psi on the trail. Our theory is that at 12 psi they slip, at 11 psi they grab, and at 10 psi they come off their beads. The added height compared to our old 37s dramatically increased clearance under the diffs, bumpers, and rocker panels. It was like driving a huge flatfender just point it at a boulder patch and idle through.
Another nice thing (believe it or not) is the added weight. The extra tire width and weight contributed to an increased sense of stability. We didn't feel like we were going to tip over on obstacles that used to feel a little spooky with smaller, lighter tires.
However, the best part of wheeling a fullsize on tires like this is the gawk factor. Spectators totally lose it when they realize there's a fullsize coming up the trail. The crowd follows you, so don't try this unless you're a total ham.