The Jeep Wrangler TJ has the most aftermarket attention of any four-wheel-drive made. When we heard that Pro Comp Suspension had a 4-inch long-arm kit for the '97-'02 Wrangler, we initially thought it was just another long-arm package. We went tosee the prototype kit at Pro Comp's Southern California facilities and spent a day abusing the suspension off-road, and were able to exam all the cool features that make this kit unique.
Concentrating on a low "roll center" and building a suspension that would perform well in all types of environments, Pro Comp decided to do some out-of-the-box thinking and really develop a kit that could compete at the top end of suspensions. We were told that some aspects of the kit shown here may not make it into full production, but we hope that these quality features remain in the product that they already have here.
By the time you read this, the kit should be available in a variety of configurations. Choose what meets your needs and try it out.
Although the kit cleared the 35x12.50s without any trouble, we did find that under extreme articulation the tires rubbed the inner lip of the fenders. We would suggest trimming off the excess fender to solve the problem. Also, the shocks as tested were an upgradeable MX6R in the rear and MX6 in the front. This gave us the ability to change the valving and handling of the Jeep with a few clicks of the knob. You can expect around 10 inches of travel from this setup as well.
Keeping the Jeep tracking...
Keeping the Jeep tracking straight is Pro Comp's adjustable track bar and super-stout track-bar bracket. Note that the track bar was sleeved at the main bend over the differential housing. This allowed it to not only gain strength, but be positioned at a low enough point to clear the housing and maintain proper geometric angles. A drop pitman arm is standard with all long-arm kits as well as the fully adjustable upper-control arms that bolt into the factory locations.
The sway-bar end-link retention...
The sway-bar end-link retention device is one of the most innovative and useful things we've seen in a long time. No more searching for bungee straps on the trail with this setup. A quick slide of the retaining rod at the bottom of the sway-bar mount and you fasten the bar between the provided end-link holder that is connected to the body of the sway bar. As for the actual sway bar itself, it finds support with a bracket cleanly positioned in the inner fenderwell.
The bellypan is 3/16-inch...
The bellypan is 3/16-inch sheet that has been strategically bent to add both support and ground clearance. This completely bolt-on subframe design makes this kit extremely user-friendly in both installation and service. Comprised of three main pieces, the bellypan was engineered with all you do-it-yourselfers in mind. Ever tried bolting one of those big heavy skids over your head without help? Pro Comp made life easier by incorporating two welded-in nuts on either side to easily install the bellypan without killing yourself in the process
The transmission support member...
The transmission support member is independently bolted between the two halves of the control-arm mounts and allows for easier access to vital drivetrain components. Another major benefit of this is having the ability to service major parts without disassembling your entire suspension.
We had the opportunity to...
We had the opportunity to compare the prototype version of the control-arm mount (blue) to the production version (bare metal). We're pleased to report that the production version appears to be a slightly improved version of the prototype, complete with a few more bends for added clearance and some minor adjustments to help keep it simple and strong.
The lower control arms are...
The lower control arms are another really cool feature on this preproduction kit. Designed with high clearance and brute strength in mind, these custom-built arms sport hand-welded braces that welcome abuse. If you look closely to where the rod end is threaded you will notice that there isn't a jam nut. Replacing it is a race-inspired setup that uses a Grade 8 bolt to maintain pressure on the threads and also eliminate the headaches and clunks often associated with jam nuts.
The rear suspension is comprised...
The rear suspension is comprised of two long lower arms and two precision bent upper arms that run a combination of bushings and top-of-the-line Heims. The kit we were working on used a lot of the factory hardware for the control-arm bolts, but we're told that a complete package of upgraded nuts and bolts will be provided with the full production kit.
Adjustable four-link uppers...
Adjustable four-link uppers connect to the bolt-on truss, which also holds the rear sway bar in place. Other components of the kit include rear sway-bar end links, brake lines, and a new axletube breather that requires you to drill into the axle, due to the truss covering up the original breather hole. Due to the high-clearance bellypan and travel allotted by the suspension, a slip-yoke eliminator will be need along with a new rear driveshaft.
As head of R&D, Ryan Kennelly...
As head of R&D, Ryan Kennelly was able to walk us over the kit inch by inch, as he tightens down one of the eight bolts that cup the axle truss securely to the axletubes. A differential centering plate is provided with the kit to ensure proper alignment and added support for the differential. This is slated to be available for all factory Jeep Wrangler TJ stock axle configurations.
The fit and finish of this...
The fit and finish of this kit is top-notch. Though shown here in anodized blue, expect the production version of the kit to be offered in a satin black finish.
Roll-center design was a huge...
Roll-center design was a huge part of this kit. We pushed the Jeep into plenty of off-camber situations in the dirt, and the suspension never missed a beat. This kit performed great during hillclimbs. Many kits on the market have a tendency to unload, leaving you with the sensation that the Jeep may flip forwards or backwards. In these situations it performed outstandingly. We never felt unsafe or that the suspension was the least bit unpredictable.