Polishing a Rubi - Rancho Lift Kit

Facet #4 is jacked up - in a good way.

Mar. 18, 2008 By Jim Brightly

Rocks, water, or hillsides become much easier to cross with a Rancho 4-inch lift kit. Ride, traction, and clearance are improved.

As I’ve mentioned here before, a jewel’s facet is one of its faces. Therefore, Facet #4 of Polishing a Rubi covers one more face of the enhancements available for the 2007 Jeep Wrangler Rubicon. Right out of the box, the JK Rubicon model is arguably the best all-around OEM Jeep ever offered to consumers. As you can see in every off-road catalog, its available enhancements cover every aspect of possible improvements; some quite difficult for the home mechanic, while others are fairly simple.

The full kit includes everything you see here including new nuts and bolts if new ones are needed. Make sure you observe all the necessary safety requirements and use jackstands to carry the Jeep’s weight and not hydraulic jacks. Be safe!

Rancho includes a check-off list of all the items needed to be removed before you can get started replacing items. Remember, do not allow the front axle to hang by any hoses or cables.

Support it with a hydraulic jack that an assistant can use to raise or lower the axle as needed. Although Rancho suggests the driveshaft be disconnected from the differential, we didn’t find it was necessary (although you might).

According to Jeep information, 35-inch tires will fit under the JK’s fender flares and on its spare tire carrier, and will clear the rear bumper as well. This may well be true, but I didn’t want to try larger tires without first raising the Jeep. Since Jeep lists the ground clearance for a Rubicon as 8 inches (not including the two center pumpkins of the Dana 44 axles), the Rancho 4-inch kit will give you a full foot of clearance. Remember, when you drop air pressure for improved traction, you lose some of those original 8 inches (you can lose as much as 2 inches if you run really soft tires. A 4-inch lift could be the difference between a holed and leaky gas tank—sometimes difficult to get home that way—or a few scratches in the tank’s paint.

Drill a 5/16-inch hole in the center of the spring axle pad; then tap (thread) the hole for 3/8x16 bolt.

When you compare the OEM coil spring (left) with the Rancho unit, you can see the new one is both longer and made from heavier material.
Hang the bump stop spacer on the coil spring, insert the spring into the upper mount first, and then on the axle pad.

It’s amazing that Rancho’s suspension engineers know to the fraction of an inch just what the springs’ tension, strength, and bar

Bolt the bump stop spacer to the axle pad with the supplied self-tapping screw and fully seat the spring.
Although all the steps are pretty close for both sides, on the passenger side, you will have to cut the mounting bolt for the upper suspension arm frame bracket (or remove that side’s exhaust). We cut the bolt; a new one is included in the kit.After that, install the supplied longer brake line brackets on both sides.

diameter must be to produce exactly 4 inches of lift to a JK. But that’s exactly what my JK Rubicon was lifted at each corner (original measurements were: left front/35-1/4; right front/35; left rear/35-1/2; right rear/35-1/2—final measurements before the addition of the Bridgestone Dueler A/T P285/70R17 tires: LF/39; RF/39; LR/39-1/2; RR/39-1/2). All measurements taken at the center of each fender flare.

The Bridgestone tires added another half inch to the total ground clearance. OEM Rubicon tires are BF Goodrich 32-inch diameter T/A tires, while the Bridgestone tires are 33 inches in diameter. With the switchover to 17-inch diameter rims and the 5x5-inch lug pattern, tire and wheel companies are still trying to fill the void that has resulted.

Air pressure and shock adjustment work together to produce exactly the type of ride you prefer. Off-road, lower the tires’ pressure and adjust the shocks to a lower number. I dial each shock as I lower each tire’s pressure; the pressure and dial number depend on the trail’s rating (i.e., the higher the rating, the lower the pressure and shock setting). When I get back to the highway, up go the pressure and shock setting. Each shock has nine different settings. On the JK we started with #7 but that proved too harsh on the Arizona roadways, so I adjusted it down to #5, which is perfect for freeway or two-lane roads (on a 2005 TJ Unlimited I owned for a year, it needed #9 for proper shock absorbing). Off-road, for trails rated at three or above, I set the shocks at #1; for a one or two rating, I set the shocks at #3.

Don’t forget Rubicon end links kit #RS6753B if you own a Rubicon, it’s needed to extend the control arms of the sway bar or the onboard computer will be affected. This is because Rubicons have an electronic disconnect for the sway bar to allow more wheel articulation (at 8 mph, the sway bar is automatically reconnected). Sahara and X models do not have the electronic disconnect feature, so you don’t need the kit with those models.

Speaking of the computer, once you’ve completed all the installation steps, you should have the JK’s wheels realigned, the steering wheel realigned, and have a dealer tech recalibrate the computer.

Another thing not to forget about a jacked-up JK; you’ve raised the center of gravity (COG), and the guys in D.C, love to tell us that SUVs, especially those with higher COGs, have a higher tendency—pun intended—to roll over. While the higher COG wouldn’t affect an experienced driver, it might cause an inexperienced driver to over-compensate during a rapid turning maneuver, which could lead to a condition of upset. Just be careful until you’re used to the Jeep’s higher profile.

Install the front shocks at this time. Be sure to keep all bolts and nuts at only finger-tight until everything is installed.

Remove and replace the Pitman arm. The new Rancho Pitman arm has a 4-inch drop. It may prove very difficult to remove the OEM Pitman arm, so you’ll probably need a strong assistant. Then re-attach all the suspension brackets and arms to the frame and differential.

Insert the bolts in the upper suspension arm and bracket, and finger-tight the nut. You can now tighten and torque all bolts and nuts, and install the front tires. Now move to the rear of the Jeep—the rear axle install is the easier of the two ends and will take only about half the time of the front—lift and support it safely, and remove the tires. You can also begin following Rancho’s removal instructions for the rear.

The right rear spring is already installed, and Eric is installing the left spring. You’ll also have to extend the brake lines in the rear.

The sway bar brackets will also have to be shimmed down from the frame with the supplied inserts. The track bars also have to be lengthened to keep the rear axle properly aligned with the rest of the Jeep.

Extend the bump stops on both sides, install the rear shocks on both sides.

Now that everything is in place, tighten all the nuts and bolts, then torque them. After it was all installed, I took the Jeep to the Fort Mohave Tire Pros shop for wheel and steering wheel alignment.

The added clearance really works on high centered humps in the trail. Bridgestone’s Dueler A/T tires, even though they are not light truck tires, performed very well in the dirt with quiet traction. Highway traveling between trails is much quieter with the new tires as well, and the ride is much improved.

(Author’s note: For those of you who don’t care to get dirty while off-roading, you should consider installing Rancho’s remote control kit for the RS9000 shocks. Then you wouldn’t have to leave the comfort of your driver’s seat to dial in the shock stiffness exactly.)

Be sure to properly torque all bolts to the specifications given by Rancho in its instructions. I also wish to thank Eric Cortez, avid Jeeper and manager of Ron's Tire Pros in Fort Mohave, Arizona, for all his work on installing this kit.

Source: Rancho Industries
6925 Atlantic Ave.
Long Beach, CA 90805

Editor’s Note: Facet #5 falls right in between #3 and #4 in the difficulty range—replacing the OEM black fender flares with matching-color flares from Bushwhacker. Look for this installation article in the months to come.

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