The Birth of Tri-County Gears Rock Crawler - Technical Articles

This Wrangler YJ would probably go unnoticed if it weren't for its eye-catching yellow-and-blue paint job. At a quick glance it could even be taken for a near-stocker with a good 'cage and 35s, but a closer inspection reveals that this YJ is heavily modified where it counts.

That's testament to Tri-County Gear's ability to build a very functional and well-thought-out vehicle that is still simple. But that the YJ ended up being almost a completely different vehicle than it was as a stocker doesn't mean that everything was altered during the buildup. The hood, steering wheel, gauge cluster, engine innards, transmission (rebuilt), glove box and the gas tank are still much as they were when they left the factory in '89. Of course, that leaves quite a lot that was improved, tweaked, reengineered and changed. The result is a very capable vehicle, no matter how low-key it may appear to be.

The last welding slag on the shop floor probably hadn't yet cooled before Jason Bunch threw the largely unproven Wrangler on the trailer and promptly took Fifth at the Warn Rock Crawling Championships in Johnson Valley, California, last year. Not bad for a fresh vehicle. A few more weeks, tweaks, and adjustments later, the Wrangler faced 24 Hours on the Hammers, a gig where the aim is to run all five Hammer trails within a 24-hour period. It took Jason and the YJ a mere 5 hours to accomplish the feat.

Very impressive, and a fact that speaks to the effectiveness of the modifications that this YJ carries. Please note that as of this writing, Tri-County Gear can no longer supply the Warn XCL suspension since Warn has discontinued it. However, building vehicles from the ground up is something the Tri-County crew still does for its customers. Just don't expect it to be done quite as quickly as the marathon wrenching session that made this Wrangler happen.

The well-worn ’89 YJ didn’t look too spectacular, although some felt that removing the front clip was a big improvement. Here, the 170,000-plus-mile motor—one of the few things left mechanically untouched—can be seen.
The well-worn ’89 YJ didn’t look too spectacular, although some felt that removi
To say that the Wrangler was built from the ground up isn’t exactly correct, since more often than not, the frame was worked on upside-down. The goal was to keep the center of gravity low, so the Warn XCL suspension’s skidplate was tucked up to the frame, making it necessary to cut reliefs in the frame to make room for the front control arms.
To say that the Wrangler was built from the ground up isn’t exactly correct, since mo

Material was formed and added to the cutouts to maintain the frame’s strength, and spotter-to-be Steve Hastings is seen grinding the welds smooth. Notice the skidplate/suspension mount that hangs no lower below the frame than the thickness of the metal.
Material was formed and added to the cutouts to maintain the frame’s strength, and sp
To have the skidplate flush with the frame is great for ground clearance, but requires a fair number of mods up above. The rear control arms were bent to keep them off the rocks, and the mounts had to be modified to make the bushings sit correctly at normal ride height.
To have the skidplate flush with the frame is great for ground clearance, but requires a f

Getting all the angles just right and eliminating any bind took a bit of trial and error, but it’s a whole lot easier to get things working right at this stage than it is to fix the flaws once the vehicle is complete. Here the custom Tri-County Gear reverse-rotation Dana 44 is devoid of its Detroit Locker, Warn full-floating axles, and 4.56 gears.
Getting all the angles just right and eliminating any bind took a bit of trial and error,
When the skidplate went up, so did the drivetrain. A fair amount of the floor had to be cut out to make room for the rebuilt AX5 transmission, 2.72:1 Klune-V Extreme Underdrive, and 4.3 Atlas II transfer case. Overall gearing with this setup is an impressive 209:1, quite manageable for the tired motor.
When the skidplate went up, so did the drivetrain. A fair amount of the floor had to be cu

After painstakingly scraping the bottom of the body tub clean (including what remained of the floor pan), a new raised version was constructed and welded in place.
After painstakingly scraping the bottom of the body tub clean (including what remained of
Critical supports and reinforcements for seatbelts and such were welded in where needed. This would have been the best time to build a body lift into the tub, but Jason wanted the lowest possible center of gravity, so he cut the fenders instead.
Critical supports and reinforcements for seatbelts and such were welded in where needed. T

With the body mods done, the tub was taken to nearby L&G Enterprises for smoothing, prep, and a very yellow paint job.
With the body mods done, the tub was taken to nearby L&G Enterprises for smoothing, prep,
While the body and frame got the vast majority of attention, the little 2.4L four-cylinder wasn’t completely left out. Standard Flywheel made a custom weight for the flywheel that added about 9 pounds of much needed inertia, compared to the stock 25-pounder on the right.
While the body and frame got the vast majority of attention, the little 2.4L four-cylinder

Jason settled for the 2.72:1 Klune-V underdrive, suspecting the 4:1 version in combination with the 4.3:1 Atlas II T-case would be an unsuitable ratio for dunes and milder trails. As it turned out, the Atlas in high range and the Klune-V in low works great for those occasions.
Jason settled for the 2.72:1 Klune-V underdrive, suspecting the 4:1 version in combination
A custom rollcage was bent and welded up at Tri-County Gear. Notice that the front down-legs go to the dash rather than to the floor.
A custom rollcage was bent and welded up at Tri-County Gear. Notice that the front down-l

Tri-County spring-over steering was used on the Detroit Locker–equipped reverse Dana 30 axle to keep the tie rod out of the weeds and to provide good steering geometry.
Tri-County spring-over steering was used on the Detroit Locker–equipped reverse Dana
Knowing that the reverse Dana 44 rear axle would see its share of contact with rocks, a substantial skidplate was built onto the housing, here seen upside down.
Knowing that the reverse Dana 44 rear axle would see its share of contact with rocks, a su

A tighter-than-normal turning radius was achieved by grinding the Warn high-strength-alloy front axles a little here and there as needed. Such clearancing must be done carefully and kept within reason so as to not weaken the components.
A tighter-than-normal turning radius was achieved by grinding the Warn high-strength-alloy
Air suspension has undeniable advantages, and a pair of bags on the rear control arms can be used to increase the already respectable 23-inch clearance under the skidplate if needed. And, yes, the chassis is still upside down.
Air suspension has undeniable advantages, and a pair of bags on the rear control arms can

The merciless cutouts in the frame shown earlier are now functional and good looking. They allow the same travel as a normal Warn XCL suspension, there’s just nothing hanging down anymore.
The merciless cutouts in the frame shown earlier are now functional and good looking. They
About 50 days into the process, the drivetrain is installed in the now-uprighted chassis. For weight distribution and driveshaft purposes, the engine is placed about 7 inches forward from stock. With the transfer case raised, that leaves the package sitting near level. The wheelbase ended up about two inches longer than stock, which also helps rear driveshaft angularity.
About 50 days into the process, the drivetrain is installed in the now-uprighted chassis.

A near complete rolling chassis about to join a freshly painted body. It’s moments like this that justify all the work. However, the crew knows all too well that the vehicle is far from done, and the clock is ticking. Not even the 35-inch Goodyears on ARE wheels with Champion bead locks are installed yet, but you can see the Warn hubs with 5-on-51/2–inch bolt patterns in place.
A near complete rolling chassis about to join a freshly painted body. It’s moments li
Maybe it’s not worth protecting, but the YJ’s four-banger still gets its own rollcage—just in case.
Maybe it’s not worth protecting, but the YJ’s four-banger still gets its own rol

A cooler for the power steering is nestled in under the radiator. Steering components can get a real workout on rock-trails.
A cooler for the power steering is nestled in under the radiator. Steering components can
MNotice how the tucked-up skidplate and control arms leave very little for nasty rocks to grab. Tri-County also built the CV-jointed driveshafts in house.
MNotice how the tucked-up skidplate and control arms leave very little for nasty rocks to

PHundreds of little details, such as plumbing, wiring, and an interior remain to be done. Easy, and when these tasks were complete, the YJ was ready for rocks. FW
PHundreds of little details, such as plumbing, wiring, and an interior remain to be done.