Finally! Someone has made a fullsize 4WD IFS kit that increases wheel travel. We made the plea numerous times over the years: an IFS kit that would not only increase the height of the truck, but also increase the amount of suspension travel.
Rockkrawler has answered our prayers with its new Desert Race IFS coilover conversion system for '99-and-newer Chevy 1500s. The system raises your vehicle about 5 to 6 inches and allows the fitment of 33-inch tires, or 35-inch tires with some minor fender trimming.
The front kit includes Fox coilover shocks, drop knuckles, subframes, shock mounts, and other necessary hardware. And since the coilovers will now be suspending the vehicle, you can ditch your torsion bars. The rear of the truck kit gives a combination of rear add-a-leaves and blocks, but the rear of the Tahoe and Avalanche kit has a new long-travel five-link setup.
We ordered a kit (the five-link of course because we're suckers for extra work, especially when we're having the pros at Robby Gordon Off-Road put it on) to try out on a Chevy that we hadn't even found yet. Since this was the first kit of its kind that we know of, we wanted it ASAP. By the way, anyone out there got a new Tahoe we could punish?
Here is the entire Coilover Desert Race System from Rockkrawler Suspensions. We had previous good experience with one of its kits on our own vehicle, so we were optimistic about this kit's operation. The system gives about a 6-inch lift in front and 5 inches in the rear. The front is a torsion-bar-eradicating Fox coilover setup, while the rear is a five-link setup using four new control arms, a new track bar, coils, and long-travel shocks.
We did the installation at Robby Gordon Off-Road in Anaheim, California, with techs Jorge Flores and Jaime Amundson. They started by removing all the old suspension and the front drivetrain. It is necessary to remove some original brackets and hangers in the kit as Flores is doing here.
Rockkrawler's instructions also dictate removing the upper mount of the differential, as it will not be used in the truck's future form. We don't really like this method of mounting, since we're suckers for as much bracing as possible, but the way the kit is designed, it requires you to do so.
After all the prep was done, Amundson bolted on the subframe and then the A-arms. He left the new knuckle off until he had the upper coilover mount drilled into the factory upper shock mount. Once the coilover mounts were on, he installed the knuckles and connected the new extended antisway bar links. Labeled here is the hardware for the front suspension: subframe (A), CV shaft spacers (B), upper and lower coilover mounts (C), extended antisway bar links (D), and machined drop knuckles (E). Remember there is no torsion-bar crossmember drop bracket with this one, since this lucky owner is going to coilovers.
The Fox coilover is a bit tricky to get in, as are most nitrogen-charged shocks. If it is too difficult to get the shock in, check the pressure (hopefully you have a 200-psi pressure gauge) and release the nitrogen. The shaft will now compress and not try to rebound, but you will have to get the shocks charged up again before you drive your truck.
On a side note, we think it might not hurt to weld the lower coilover mount to the lower A-arm, as there is only one bolt and a flat side of the mount that holds it in place.
Amundson went to work on the five-link rear and was almost finished by the time we got back from a Gatorade break. The new upper control arms feature adjustable, rebuildable Krawler joints. The lower control arms have urethane bushings and both are definitely a beefy upgrade from the factory control arms. The track bar bolts into the factory location, and the new coils sit in place of the old ones. There are also extended antisway bar links for the rear. Now that the Tahoe's new suspension was complete, the guys at Robby Gordon Off-Road dropped the Tahoe onto a set of 17x8 Robby Gordon Signature wheels that were optionally powdercoated and wrapped inside a set of 33-inch Pro Comp Mud Terrains.
How'd It Work?
The owner of this '02 Tahoe was overall very happy with this suspension. We took a ride with owner James Racette to get a feel for what he described to us: "The Tahoe rides super-smooth now, soaking up the bumps much better than the factory torsion bar suspension. The rear setup works well and feels soft through bumps and dips, but firm enough to have a good amount of control. The front coilover kit works great off-road, charging through rough stuff with little effort and a good amount of control, but on the freeway, the front end bounces a little bit when hitting expansion gaps and dips in the road. Plus it's a tad low in front."
Racette has been driving his Tahoe for about a month now and to date has had no issues whatsoever, save for a rear axle on its last legs. We thought about his minor front end issue, and think we have it figured out. Robby Gordon Off-Road adjusted the suspension to sit level at the time of the build, but the coils broke in after a few days and settled more than we planned for. The minor sag can obviously be fixed by adjusting the coils down on the Fox coilover shocks, and that in turn will bias the weight of the vehicle more towards the rear. Having a sagging front end or rear end can make a suspension work much differently than if a vehicle is level, since it shifts the weight proportions that are placed on either end.