We've been lucky to have 4WD Toyota trucks since 1979 and 4Runners since they were introduced in 1984. These rugged vehicles have made daily drivers, weekend warriors, and hard-core trail rigs for numerous owners. Patterned after the sturdy construction of the venerable Land Cruiser line, the early trucks were built on a fully boxed ladder frame; they were rugged and durable. Much of that quality has lived on through the years with evolutionary refinements that have raised reliability and the driver's comfort. In this article, we'll give you a brief tour through the years, covering many of the differences and specifications.
Toyota has offered four major body styles over time. First-generation trucks from 1979 to 1983 had rounded fenderwells and round headlights. The one exception was the '83 model, which had square headlights. The second-generation truck, built from 1984 to 1988, had squarish fenderwells, and the Xtracab model was introduced in this truck line. Starting in 1989, Toyota returned to the rounded fenderwells and increased the Xtracab length from 9 to 18 inches. Longbed models were also built up until 1992. For the '95.5 model year, Toyota introduced the Tacoma line with a more rounded, sleeker body, and in 2001, brought us the long-awaited Double Cab truck.
The 4Runner was introduced in 1984 with the same body style as the second-generation trucks. Only a two-door model was available, and these had a removable fiberglass rear top. Starting in 1990, the 4Runner had a full steel body, updated to match the third-generation trucks. Four-door models were introduced and the two-door version discontinued in 1992. Then, in 1996, the third-generation 4Runner body was offered. Its styling changed to more closely match that of the Tacoma.
Standard-bed trucks.............102 to 103 inches
Longbed trucks....................110 to 112 inches
Xtracab('84-'88 trucks)..........112 inches
Xtracab ('89 and later)...........121 to 122 inches
Tacoma Double Cab.............122 inches
4Runner..............................103 to 105 inches
Over time, Toyota has offered three styles of front suspension. Early U.S. models up through 1985 came equipped with a front straight axle and leaf springs. Beginning in 1986, Toyota converted to an independent front suspension (IFS) using A-arms and upper torsion bars on both the trucks and 4Runners. Early IFS models used 22.8mm torsion bars, but size was reduced slightly in 1988 to provide a smoother on-road ride. With the introduction of the Tacoma line and newer 4Runner, the front suspension was swapped over to a coil spring, independent double-wishbone setup. Front suspension travel increased 25 percent or more with this change.
Straight-axle and IFS trucks used recirculating-ball steering boxes. The straight-axle trucks had a push/pull-style drag link, while the IFS trucks had a cross link and idler arm assembly. Power steering was available from 1979 but was only an option on some vehicles. The Tacoma line was equipped with power-assisted rack-and-pinion steering.
Toyota 4x4 trucks have always been equipped with a traditional leaf spring rear suspension. In 1989, the springs were lengthened about 3 inches to improve ride quality. Early 4Runners also had rear leaf springs but changed to a coil-spring linked suspension in 1990. Some Tacomas have been offered with a Toyota Racing Development (TRD) off-road package consisting of upgraded suspension components, including Bilstein gas shocks.
Over the years, Toyota has offered a number of engines in its trucks and 4Runners. 1979 and '80 models used the 20R engine, a 2,200cc carbureted four-cylinder. The larger 2,400cc 22R engine made its debut in 1981 and stayed with the line until 1995. Both carbureted and multiport fuel injection versions (22RE starting in 1985) were offered. All '88-and-later trucks have been fuel-injected.
To increase engine power until it could introduce a V-6 engine, Toyota sold a turbo-version 22RTE in some models in 1986 and 1987. In 1988, the 3.0L V-6 3VZE engine was introduced. The 22RE and 3VZE were replaced with new engines in the Tacoma line. Engine size was increased and the new engines were the 2.7L 3RZFE and the 3.4L 5VZFE. There were also a few odd diesel 4WDs that made their way to the U.S., but those are quite rare.
The four-speed manual transmission was the only option in 1979 and 1980. This was a relatively weak gearbox and could suffer from premature bearing failure. Later the following year, the five-speed was available. It had a slightly longer housing and offered a 15-percent overdrive. Five-speed models up through about 1984 can also suffer bearing failure. In 1985, the transmission was changed to a more durable design and the bearing problems ceased. Throughout the years, the manual transmission alternated, with some versions having a removable bellhousing and some not. Automatic transmissions have been available in most all the trucks and 4Runners as an added option.
Toyota has varied the axle gearing over the years to accommodate the various engines, transmissions, and tire sizes. Gearing has ranged from a 3.42:1 to 4.88:1 ratio. The table below shows a quick summary of the axle ratios offered.
'85-'88.......4.10, 4.30, 3.42 (turbo)
'89-'94.......4.10, 4.30, 4.56, 4,88(not all gears all years)
4Runner......3.42, 3.91, 4.10
Toyota had been offering an electric locking differential in its FZJ80 Land Cruiser line since 1993. This proven differential style was then made available as an option on some Tacomas and third-generation 4Runners. The locker is engaged using a dash-mounted switch.
Through the years, Toyota has used three basic transfer case designs in its trucks and 4Runners. The High-range ratio is 1:1 in all these Toyota transfer cases. Low-range ratios have been either 2.28:1 or 2.57:1. Typically, pre-Tacoma four-cylinder trucks and 4Runners with manual transmissions used the geardrive 2.28:1 ratio. The four-cylinder turbo, V-6, some automatics, and Tacomas used the 2.57:1 chaindrive. Pre-Tacoma trucks have a passenger-side front drive output, while Tacoma-era trucks have a driver-side output.
In the early years, Toyota only offered traditional manual-locking front hubs to engage 4WD. Some mid-'80s trucks had automatic locking hubs that worked well when new but tended to fail after some years or a large number of use cycles. Starting in 1986, the transfer case could be shifted from 2WD to 4WD while moving. Another upgrade came with the addition of the 4WDemand system in 1989 that allowed shifting from 4-Hi to 4-Lo while moving slower than 20 mph. The 4WDemand system uses fixed hubs at the wheel hub such that the front axleshafts and CV joints are constantly turning. A vacuum-actuated system engages the front axle drive when the transfer case is shifted to 4WD. Tacoma-era models have come with both manual-locking hubs and fixed hubs, depending on model and package options.
You can see that Toyota 4WD trucks and 4Runners have changed a good bit over the 25 years they've been in existence. Their design has evolved and changed to meet the needs of consumers. Some wheelers prefer the quieter, smoother comfort of the latest coil-sprung versions, while others prefer the greater trail-running potential of the leaf-spring rigs. Fortunately, Toyotas tend to last a long time, so there is quite a variety of models out there to choose from.