The Toyota rear axle is a versatile unit. With the wide array of upgrades and options avai
Toyota truck and 4Runner rear axles are plenty tough in stock form, but there are a number of upgrades available that can make them even tougher for hard-core users. In a previous article ("Toyota Axle Beef," June '99) we discussed fortifying front axles. Here we'll discuss the other end of your Toy, and a few pieces in between.
Basically two versions of 8-inch rear axles have been used over the years. Production rear axles through the 1985 model year (those with a straight front axle) measure 55 inches flange to flange. When Toyota changed to IFS in 1986, its engineers widened the rear axle to 58 inches to match the wider front suspension.
|Ratios by Year |
|1979 ||4.10:1 |
|1980 ||4.38:1 |
|1981 ||3.90:1 |
|1982-1984 ||4.10:1 |
|1985-1988 || 4.10:1, 4.30:1, 3.42:1 (turbo) |
|1988-1994 ||4.10:1, 4.30:1, 4.56:1, 4.88:1 |
|1995 ||3.91:1, 4.10:1 |
|Tacoma ||3.42:1, 3.91:1, 4.10:1 |
Along with widening the axle, Toyota engineers also increased the tube diameter from 65mm to 80mm in diameter, and increased the drum-brake size. The axle shafts were lengthened 1.5 inches per side, but the third members are completely interchangeable between the early and later years, through 1995 when Toyota changed the axle for the Tacoma.
The differentials that came in turbo-engine-equipped trucks, or in V-6 trucks, contain four spider gears as opposed to two spiders on the four-cylinder versions. This is often not significant as lockers or other traction aiding devices are added, replacing the stock carrier. However, the V-6 third-members do carry beefier ring-and-pinion gears than the four-cylinder ones.
Stock Toyota axle ratios have varied over the years, as shown in the following table. Not all gears shown were available in each specific year from 1985 to 1994. Ratios varied based on engine, tire size, and transmission configuration.
The wider version rear axle is three inches wider overall, flange to flange. The differenc
The narrow axle uses 10-inch dual-servo drum brakes (right), while the wider axle uses 11.
All rear Toyota truck and 4Runner axles use beefy 30-spline axle shafts. These are the sam
The third members used in the four-cylinder and V-6/turbo vehicles (right) are interchange
Stock Toyota axles use U-bolts mounted with the nuts on the bottom, protruding through sta
Rear axleshaft failure is not that common, but can occur on trucks used for hard-core 'whe
Many rockcrawlers with early-model narrow-track axles have opted to swap in the later wide-track axles to widen tire stance and prevent the inside face of the rear tires from rubbing on the frame rails under extreme articulation. Swapping to the newer axle is a bolt-on affair.
In any case, Toyota rear axles are versatile and reliable performers. With the wide availability of aftermarket beef-up parts, and a number of stock interchange options, you can set up your truck or 4Runner to tackle the four-wheeling you do.