Moses Ludel’s 4WD Mechanix Magazine – BFG All-Terrain T/A Tires for the Lifted XJ Cherokee
B.F. Goodrich All-Terrain T/A KO Tires for the Jeep XJ Cherokee 4×4!
In this HD video, see the new B.F. Goodrich All-Terrain T/A KO tires fitted to the magazine’s XJ Cherokee 4×4! With a six-inch long arm lift, the Cherokee requires 33″ diameter tires on 8-inch wide wheels—with shallower backspacing than stock to achieve a 2-inch wider track width. This HD video is high resolution HD 1080P that can be opened to full-screen for maximum detail and viewing advantage! B.F. Goodrich is our choice for both the Dodge Ram 3500 4WD Quad Cab and the ’99 XJ Cherokee 4×4. Mounting and balancing require a skilled shop. We turned to Purcell Tire & Rubber Company at Reno, Nevada. 33″ tires have been on this lifted Cherokee for seven years. Time for new tires on the six-inch lifted 4×4. XJ Cherokee Dana 30 front axle and rear Chrysler 8.25″ axle each boast ARB Air Lockers and a 4.10:1 gearing change. This Jeep 4×4 is a true trail-and-street, multipurpose machine! Our tire size choice for the Jeep XJ Cherokee 4×4 has been LT285/75R-16. The old tires were Load Range E. This time, we opted for Load Range D—and less stiffness. This is still over-capacity, an 8-ply rated tire typically used on full-size pickup trucks. For this much lighter, 3,800 pound Jeep (curb weight with aftermarket accessories in place), Load Range D is way beyond the vehicle’s requirements. Wheel rims are American Racing’s ATX Series Mojave style in 16″x8″ size with 4.48″ backspacing. This provides a desirable track width increase without the need for aftermarket fender flares. The vehicle performs well off-road, and 2-inch wider than stock track width helps offset the higher center-of-gravity created by the suspension lift. These Teflon-coated wheels have been thoroughly tested over the last seven years! Short American Racing chrome valve stems offer maximum sealing yet have a short stem for avoiding off-pavement debris and damage. Rim clamp style tire changer works best for alloy wheels. Although not a “European style” changer, careful use of this equipment can mount these tires without damaging the Teflon coating. Experienced tire personnel are your best assurance of tire reliability. Note short, metal valve stem’s length, well out of harm’s way. Seating the tire beads against the rim edges assures a good tire seal and reliable service. At right is the actual wheel weight requirement, excellent for a tire this size. New weights in place and zero balanced, this wheel/tire will go to the front (steering) end of the vehicle for desirable handling and smooth ride quality during initial run-in of the tires. Tires get rotated and re-balanced each 3,500-5,000 miles. In the video, see how balancing and wheel runout are an important part of tire service. Wheels and tires require periodic rotation and re-balancing, especially on Jeep 4x4s and Dodge Ram 4WD trucks with beam front axles. At right, final torque of wheel nuts is set with a calibrated torque wrench—100 ft-lbs for this Jeep XJ Cherokee’s 1/2-inch wheel studs and nuts. Use correct nuts with alloy wheels; make sure the thread length is adequate. Here is the OEM Jeep factory door sticker with recommended tire pressures—for the OEM tire size! Note that 33 PSI is for a P215/75R15 tire size. At right, new oversized tires reveal Load Range D with a substantially higher load capacity per tire. These are true “truck tires”. 33 PSI would likely be over-inflated on this lighter weight vehicle. Tire inflation pressure is critical. While each tire and vehicle application has different needs, we found that the Load Range E oversized tires behaved best on-highway at 24 PSI on this XJ Cherokee 4WD. Anticipated PSI for this Load Range D application will be 25 to 28 PSI. We started at 25 PSI and will increase the cold pressure gradually to 28 PSI during tests. Weight distribution is fairly even, as noted with the OEM tire pressure settings. Note the unique, curved tread design that helps compensate for caster/camber and a solid beam front axle’s steering geometry. More than good looks, this is a functional and versatile vehicle. We have nearly 50K miles of testing on the Full-Traction Suspension system, the wheel-and-tire package, ARB Air Lockers and the 4.10 axle gearing. With the AW4 transmission and overdrive, one option would be the axle gearing choice. 4.56:1 might work better than 4.10:1, especially with the added 600-plus pounds of aftermarket bumpers, a Warn XD9000 winch and oversized wheels/tires. Though not available, 4.27:1 ring-and-pinion gearsets would be even better! To get the “official” B.F. Goodrich design and application details for the BFG All-Terrain T/A KO tires, click here to the B.F. Goodrich site!