Those of you who've been following my blogs on our website (feel free to add your comments there, by the way) and our Facebook page know that I've been working on the JK Trailrunner project, a yellow 2008 two-door Rubicon. It's been interesting to track down problems and fix them. For instance, I've been mixing, matching, cutting, and trying different coil springs and shocks. The vehicle exhibits markedly different characteristics with each combination. In addition, I've been chasing rattles and Diagnostic Trouble Codes (DTCs).
I found a big rattle because friends came over to the house and watched me drive up and down the curb until they figured out it was the rear bumper frame bracket hitting the right rear corner of the body. At least one of the DTCs had to do with a fuel system leak. This was easy to believe, because every time I let the JK run for over a couple of minutes I could smell gasoline fumes. Adhering to the old adage that when something's wrong, check the last thing worked on, I looked at the vapor canister that had been relocated with the Kilby Canister Relocator. The hoses that connected to the hard plastic lines were loose. So loose, that even though I had pushed the lines into them about 2 to 4 inches, they were obviously not sealing. Hose clamps everywhere solved the issue. Simple fix and there are no more DTCs and no more fumes.
I took the Jeep out yesterday for a shakedown cruise south of the house. The roads aren't difficult, but they're scenic and afford both high-speed trail running and some slower crawling up (or down) the Hurricane Cliffs. There are side canyons along the way that supply interesting ledges and intermediate challenges. In other words: perfect trails for testing a project vehicle.
I aired down and took off into the dirt. Starting slowly, I listened for new rattles (there were some), watched for DTCs (there were none), and began to get to know my JK. Once into Arizona, I opened it up. The speedo needle sat on 75. I bumped it up to 80. I'm not exaggerating - 80 mph! The Jeep was smooth and controlled. I slowed, as there was a canyon I wanted to drive up to see how the JK worked on ledges. The NVG241OR Rock-Trac transfer case shifted easily into low range and I locked the rear, then front, E-lockers and hit the swaybar disconnect switch. The steering was effortless, even with the front locker engaged. Everything worked and the Jeep went up the trail easily. I slowly climbed a few ledges and dry waterfalls to see how it felt in off-camber situations. It was all right, but I have more coils to try out.
Back to the main road and up the cliffs, the Jeep crawled fine. The original pioneer wagon trail is across a small ravine from the current road, but there are choices along the way where an older, rougher road can be followed. Some fun ledges, a sidehill, and then I popped over the top of the rim. Now, it was time to turn on the Sirius satellite radio and cruise up the graded road. I didn't push it, but was surprised when I looked at the speedometer to see 60 mph. The JK was that easy to drive fast. There were some new culverts put in by the BLM and the road made S turns over every one. I tested the JK with the ESP off and on. Surprisingly, the ESP helped me hit the S turns faster than I could without it. Yes, the ESP is terrible in the sand and other places off-road, but sometimes it's worth having.
While there's still work to be done, I'm very pleased so far. I've thought back on my past vehicles from decades ago that couldn't go over 15 mph on these roads and would have taken most of a day to make the trip. The JK Trailrunner is a street-legal vehicle that can be driven every day, can be used for driving fast (very fast) in the dirt, then be locked up in low range for tough trails. It's comfortable, clean, and simple.
It's easy to build old-school, slow--trail 4x4s. There's no reason in 2010 that 4x4s can't be built to go fast safely, too. Can you imagine what trail rides in vehicles built like this will be like? Goodbye boredom!