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

Posted in How To on March 1, 2008 Comment (0)
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1979-1995 Toyota 4x4 Builder's Guide - How To Trail Your Toyota
An early-model Toyota pickup tackles the trail. The vehicle is equipped with a Warn hub conversion, a set of rock sliders, and a winch bumper. All of the Toyota models from '79-'85 make great trail rigs and many upgrade parts are available. An early-model Toyota pickup tackles the trail. The vehicle is equipped with a Warn hub conversion, a set of rock sliders, and a winch bumper. All of the Toyota models from '79-'85 make great trail rigs and many upgrade parts are available.

Over the past 29 years, Toyota trucks and 4Runners have become some of the most popular trail rigs around. Though entirely capable in stock form, the Toyota aftermarket has developed scads of upgrade parts for these long-lasting 4x4s. The Toyota 4x4s covered in this article were produced from 1979-1995 and include first- and second-generation 4Runners and fourth-, fifth-, and sixth-generation pickups. Each generation represents a different body style. The year 1985 marked the last year of the solid front axle and the first year of EFI. This makes '85 EFI-equipped Pickups and 4Runners a key year for those looking to purchase a fixer-upper trail rig. Expect to pay a little more for this much sought-after year but consider that you'll get more versatility and power in as-purchased form.

Engine
With five different engines under its belt from '79-'95, Toyota trucks and 4Runners definitely improved with age. The early 20R and 22R engines made less than 100 hp, but the later-model 22RE EFI engine made about 115 hp. The 22RTE Turbo produced about 135 hp and the V6 made 150 hp, making it a massive improvement to this historically under-powered vehicle. The 20R and 22R engines are carbureted. The carburetor-equipped 20R was only used for the first couple years until replaced by the carb-fed 22R, which earned a spot under the hood until 1988. Some truck and 4Runner models received the 22RE starting in 1985, and the 22RTE Turbo engine was also included in the lineup in '86 and '87. The 22RE was used through 1995 as the base-model engine alongside the optional 3VZE V6.

A solid-axle swap second-generation 4Runner ('90-'95) makes its way down the trail on a set of 34-inch Dick Cepek Radial F-C tires. This model year 4Runner was originally equipped with IFS front suspension and coil-spring four-link rear. A solid-axle swap second-generation 4Runner ('90-'95) makes its way down the trail on a set of 34-inch Dick Cepek Radial F-C tires. This model year 4Runner was originally equipped with IFS front suspension and coil-spring four-link rear.

If you're seeking V8 power from a four-cylinder, then upgrading performance on the 20R and 22R engines can be an expensive process. However, if you simply want increased reliability and a slight hop-up in horsepower and torque, you may be able to build your Toyota engine to perform to your expectations. Ensuring that the engine is in good running condition should be your first step, and it can be followed by installing a high-flowing air filter. Many will go with a set of headers, a high-flow catalytic converter, and a higher-flowing, larger diameter exhaust (the stock exhaust is small and constrictive) after this. A new cam will further benefit the open exhaust and headers and all told can offer an additional 20 horsepower. Cam changes in duration and lift vary to how each vehicle is set up in regards to gearing, tire size, and what engine enhancements are already in place. A new cap and rotor and plug wires can also re-awaken a tired stock engine, and a heavy-duty aluminum radiator will greatly aid cooling. You can also elect to invest your money in transfer case and axle gearing, which will allow the little four-cylinder to idle its way over obstacles.

If big horsepower is your goal, then you'll likely want to consider swapping out your 20R or 22R for a V6 or V8 powerplant. A lot of parts - actually everything you need - can be purchased to complete an engine swap; including motor mounts, modified oil pan (for front diff clearance), headers, and drivetrain adapters. The 3.4L V6 engine used in Toyota Tacoma pickups makes a great swap, and Off Road Solutions has a kit to swap this engine into '79-'95 models. For those who want to stay away from a complex conversion, companies such as LC Engineering and DOA Racing Engines offer high-performance 22R and 22RE engines custom-built to each application.

A well-equipped first-generation 4Runner crawls through the rocks with ease. Note the tube half-doors and the long-travel front shock mount. Sky Manufacturing offers long-travel rear shock mount that fits all '79-'85 trucks and 4Runners. A well-equipped first-generation 4Runner crawls through the rocks with ease. Note the tube half-doors and the long-travel front shock mount. Sky Manufacturing offers long-travel rear shock mount that fits all '79-'85 trucks and 4Runners.

Transfer Case
From 1979 to 1995, several varieties of Toyota transfer cases were used. Most of the cases were geardriven, though two chaindriven units were also used. Geared cases used a 2.28:1 low-gear ratio but used two differently splined inputs (21-spline and 23-spline) depending on the model year it was installed. The 23-spline input in the geardriven case was used behind the 22RTE Turbo four-cylinder and can be interchanged with the 21-spline input in any geardriven case. The 23-spline input will hold up to higher horsepower and is ideal for V6- and V8-converted Toyotas. Chaindrive cases used a 2.57:1 low-gear ratio and came with 23- and 26-spline inputs depending on the year. The later-model chaindriven cases were paired with the V6 engine and can be identified by its five bolts used to secure the rear cover. The rear cover on geardriven cases is secured with seven bolts. Toyota transfer cases used both top-shift and forward-shift configurations. Most cases are forward-shift but top-shift is more desirable for projects and modifying. Marlin Crawler offers a kit to convert forward-shift cases to a top-shift.

Low gears are about the easiest upgrade to increasing a vehicle's capability. A number of manufacturers offer low transfer case gears. Advance Adapters offers its Trail Tamer gears in 2.06:1, 4.7:1, and 5.0:1 ratios. The gearing in a stock- or low-geared transfer case can be further reduced by pairing it with a gear-reduction housing, or "crawl box," that bolts between the transmission and the T-case. The crawl box will hold one set of T-case gears and the stock T-case will hold a second set of gears. Together the gears combine to create a multitude of available gear ratios that culminate to a very respectable crawl ratio. A number of aftermarket manufacturers offer crawl boxes and complete dual-transfer case setups, including Marlin Crawler and Inchworm Gear. You can also assemble your own double T-case using an adapter plate from Inchworm Gear, Advance Adapters, or Marlin Crawler, and the front housing from a spare Toyota T-case. You'll likely still want a low-gear set for the rear case to increase the low gearing possibilities.

A broken Birfield joint can be replaced on the trail, but you better hope you brought a spare. For Toyota owners who haven't installed high-strength aftermarket Birfield joints to withstand the added stress of 35-inch-and-taller tires, a spare Birfield joint is typically a staple in the toolbox. A broken Birfield joint can be replaced on the trail, but you better hope you brought a spare. For Toyota owners who haven't installed high-strength aftermarket Birfield joints to withstand the added stress of 35-inch-and-taller tires, a spare Birfield joint is typically a staple in the toolbox.

Another transfer case upgrade that should be included with a dual-case setup is a heavy-duty transfer case crossmember. A twin stick shifter is also a helpful transfer case upgrade. The twin stick shifter allows the T-case to be shifted to 2WD Low, which is helpful in making tight turns in rigs equipped with a front locker.

Transmissions
Some early trucks used a four-speed manual transmission for a short time, but it was soon replaced by the five-speed. The '79-'83 five-speed transmission is weaker than later-model units and has a nonremovable cast-iron bellhousing. EFI trucks in 1984 came with a stouter five-speed with a removable aluminum bellhousing and four different versions of these were used through 1995 behind four-cylinder engines. From 1986-1995, two other versions of the five-speed transmission (R150F and R151F) were used along with the four-cylinder Turbo and the 3.0L V6. One automatic transmission was utilized for all Toyota trucks and 4Runners, and it was factory-married with a transfer case unlike all those used with the five-speed manual trans. If an engine or transmission swap is planned for an auto-equipped Toyota, you will also require a geardriven transfer case. Most of the late-model five-speeds are viable candidates for use behind a V6 or V8 engine swap, but the W56 five-speed used in '85-'88 EFI pickups and 4Runners is generally one of the more sought-after. Advance Adapters offers a variety of adapters to facilitate such a conversion as well as adapters to fit alternative transmission candidates such as a 700-R auto or Ford T-18 manual transmission. Toyota manual transmission strength can also be enhanced through the installation of a heavy-duty clutch and flywheel.

The Toyota four-cylinder 8-inch rear axle is a drop-out style which makes it more easily serviceable. Most Toyotas used 4.10 ratio ring-and-pinion, which is sufficient for powering up to 32-inch tires. The Toyota four-cylinder 8-inch rear axle is a drop-out style which makes it more easily serviceable. Most Toyotas used 4.10 ratio ring-and-pinion, which is sufficient for powering up to 32-inch tires.

Solid-Axle Swap (SAS)
The A-arms and the torsion bars used in the IFS setup are strong and can provide very decent performance in many off-road driving situations, but travel is limited compared to most solid-axle leaf-spring setups. Concerning strength, the biggest issue arises when the IFS axle halfshafts are forced to operate at steeper angles due to larger-than-stock tires. The shafts often break in such situations.

Since Toyota still produced a solid front axle version of the pickup for foreign markets, this meant that the front frame area on IFS rigs was still strong enough and the right width from the factory to support this setup. It didn't take aftermarket manufacturers long to figure this out, and solid-axle swap kits to replace the IFS and torsion bar configuration soon became available.

The stuff you'll need to complete an SAS is available as a complete kit from a lot of vendors, but you could make your own using used and custom parts. Many vendors offer the pieces separately for those who want to construct an SAS on their own. Most off-the-shelf kits include a front spring hanger kit, spring perches, shackles, and springs. Other items that are often included in SAS kits are front shock hoops to facilitate use of longer travel shocks. This is also a good time to locate a high-pinion frontend, but a regular four-cylinder 8-inch frontend will also do the trick. An IFS steering gear is already in place, but you'll still need some high-steer arms, a pitman arm, and a drag link and tie rod to complete the steering system. A new front driveshaft will also be necessary.

The Toyota 8-inch rear axle in IFS trucks is 3 inches wider and uses larger 11.5-inch rear drum brakes. Earlier models used 10-inch drums. The greater width permits use of larger tires without hitting the frame rails. The Toyota 8-inch rear axle in IFS trucks is 3 inches wider and uses larger 11.5-inch rear drum brakes. Earlier models used 10-inch drums. The greater width permits use of larger tires without hitting the frame rails.

Suspension
All of the Toyotas in range can accommodate up to 32-inch tires in stock form, however, the '79-'85 Toyotas can get extra clearance for a 32-inch tire using extended shackles and/or rear lift blocks. Two inches of lift can be achieved in this manner and it typically won't require new springs, shocks, or brake lines. However, a slightly taller shock will lend further ride improvements and extend wheel travel. Installing more than 3- to 4-inch lift springs will require extended brake lines and suspension and steering-correction items like an adjustable drag link, sway-bar extensions, and torque-rod drop brackets. Lifting the rear of the vehicle can be completed using lift blocks, add-a-leaves, or new lifted leaf-spring packs. Body lifts are also available for all of the Toyota truck and 4Runner models in range.

The '79-'85 trucks and 4Runners used a suspension torque rod up front to control axle wind up during braking and acceleration. The rod gets too short as a vehicle is lifted and brackets are available to adjust it to the appropriate height or adjustable rods are also available to lengthen it as needed. An adjustable drag link is also helpful in maintaining factory steering effects. You can run without the torque rod in place, but you will likely experience pull to the right under braking. This is due to the axlehousing rotating which compresses the suspension and moves the drag link. This effect will be lessened in trucks with IFS steering gears and crossover steering arrangements.

In 1986, Toyota changed the front suspension configuration of its trucks and 4Runners to use an IFS setup. The IFS used upper and lower A-arms paired with torsion bars and shocks. The rear suspension on IFS trucks and 4Runners retained the leaf-spring arrangement. In 1990, the 4Runner was redesigned to use a rear coil spring four-link suspension and front coil spring strut arrangement. Rear coil spacers and front ball joint spacers can create lift in these models. You can also replace the rear coils and control arms for more lift. All of the IFS model Toyotas can be converted to use a solid front axle and leaf-spring suspension, which will offer the greatest improvements in vehicle capability and permit use of the tallest tire sizes.

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. 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. 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.

TOYOTA TRUCK/4RUNNER ENGINES
20R '79-'{{{80}}} trucks
22R '81-'96 trucks, '84 {{{4Runner}}}
22RE '85-'95 trucks, '85-'95 4Runners
22RTE '85-'88 pickups and 4Runners
3VZE V6 '88-'95 trucks, '88-'95 4Runners
View Slideshow
View Slideshow
View Slideshow

Sources

Poly Performance
San Luis Obispo, CA 93401
805-783-2060
www.polyperformance.com
All-Pro Off-Road
Hemet, CA 92543
951-658-7077
www.allprooffroad.com
Inchworm Rock Walkin' Gear
Shingle Springs, CA 95682
530-677-8111
http://www.inchwormgear.com
Marlin Crawler
Fresno, CA 93703
559-252-7295
http://www.marlincrawler.com
Downey Off-Road Mfg.
Santa Fe Springs , CA 90670
310-949-9494

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