1979-1995 Toyota 4x4 Builder's Guide - How To Trail Your Toyota

The closed knuckle design of the Toyota front axle is shown on this stock front axlehousing. The inner and outer axleshafts are joined by a Birfield joint within the knuckle. The closed knuckle seals the Birfield from water and dirt.

Though not as desirable for all-around trail use, IFS suspensions can be modified to accept larger-than-stock tires. Aftermarket suspension systems often consist of drop-down systems that drop everything (A-arms, differential, torsion bar frame mounts, etc.) down to make more room for larger tires under the fenders. This affects ground clearance since the lift systems usually drop down the lower A-arm mount on the frame and include a spacer to be used between the stock upper ball joint and the steering knuckle to retain factory steering characteristics. Higher-end kits will replace the knuckle completely with a new lift knuckle and also use new, longer A-arms.

One cheap way to lift an IFS Toyota is to "crank up" the torsion bars to raise vehicle ride height. Cranking up the bars will make the suspension stiffer with each turn and will make the angle of the A-arms greater (they sit just about parallel to the ground at stock height). You will need to adjust wheel alignment each time you crank the torsion bars. Cranking up the torsion bars too much or installing a lift over 3 to 4 inches can cause the idler arm to break or bend. A handful of companies offer an idler arm truss to strengthen this component. Also, wheel spacers can be used to add extra width to the vehicle stance, which also effectively repositions the wheels and tires further outboard from the frame and body so that larger tires can be used.

This shattered Birfield shows some of the internal components, including the ball bearings, bearing cage, and race. Two of the six ball bearings were welded in place to display their proper location. A shattered or cracked bell is typical damage with tall tires in place.

Available factory axle-gear ratios for all years were somewhat consistent with most models receiving the 4.10:1 ratio ring-and-pinion, which will still offer decent power and torque using up to 32-inch tires. Making the leap to a 33-inch tire will require new lower axle gears, like a 4.88. A 35-inch tire will call for 5.29 gears. Basically, the taller the tires installed the lower (numerically higher) the axle gears needed. Available popular aftermarket axle-gear ratios include 4.10:1, 4.88:1, and 5.29:1. Available lockers for the Toyota axles include ARB, Detroit Locker, Detroit EZ Locker, Lock-Right, Auburn LSD, Truetrac, No-Slip, and Aussie Locker. Spools are also available and are an inexpensive means of gaining complete traction in rear axles.

Interior & Exterior
A large variety of body armor items are offered from many vendors. Body armor items include front winch and nonwinch bumpers, rear bumpers with and without tire carriers, rock sliders, transfer case crossmembers, and axle armor/guards. Quite a few weld-in in-cab cages are also available. Other exterior upgrades include fiberglass fenders, half and tube doors, roof racks, and flatbed kits. Along with in-cab rollcage kits, aftermarket seats are another popular option.