Trail-Gear Rock Assault Fully Built Rear Axle | Leaf Spring (1985-95 4Runner / 1979-95 Pickup / 1995-04 Tacoma)

Trail-Gear Rock Assault Fully Built Rear Axle

For 1985–1995 Toyota 4Runner, 1979–1995 Toyota Pickup, and 1995–2004 Toyota Tacoma leaf-spring rear-axle builds

Overview

The Trail-Gear Rock Assault Fully Built Rear Axle is a complete hub-to-hub heavy-duty rear axle assembly built from new components. It combines the Rock Assault fabricated housing, 30-spline chromoly axle shafts, rear disc brakes, bearing and hub components, and the selected Toyota third-member, ring-and-pinion ratio, and locker configuration.

The axle is supplied with bare suspension-mount locations so the leaf-spring perches can be positioned for the vehicle and desired pinion angle before welding. Width, differential style, gear ratio, and locker are selected when ordering.

Key Features

• Complete hub-to-hub rear axle assembly built from new components
• 30-spline chromoly rear axle shafts
• Complete rear disc-brake setup
• 3-inch outside-diameter axle tubes with 5/16-inch wall thickness
• Axle tubes extend 5/8 inch farther into the center section than the referenced factory-style construction
• 360-degree internal tube gusset reinforces the tubes inside the housing
• Offset tube geometry provides approximately 3/8 inch additional clearance beneath the tubes
• Press-formed 1/4-inch steel center shell with a 1/2-inch differential mounting surface
• Center-section design provides a minimum of approximately 3/4 inch additional clearance beneath the differential
• 4130 chromoly outer offset flanges
• Housing alignment checked with 3D digital imaging during assembly

Vehicle Fitment

Toyota 4Runner

• 1985–1989 Toyota 4Runner – 1st Gen – Factory leaf-spring rear suspension
• 1990–1995 Toyota 4Runner – 2nd Gen – Requires a properly configured leaf-spring rear suspension conversion

Toyota Pickup

• 1979–1983 Toyota Pickup – 1st Gen – Leaf-spring rear suspension
• 1984–1988 Toyota Pickup – 2nd Gen – Leaf-spring rear suspension
• 1989–1995 Toyota Pickup – 3rd Gen – Leaf-spring rear suspension

Toyota Tacoma

• 1995–2004 Toyota Tacoma – 1st Gen – Leaf-spring rear suspension

Fitment Notes

• Leaf-spring rear-suspension builds only.
• 1990–1995 2nd Gen 4Runner applications require a leaf-spring rear suspension conversion; these vehicles did not use a factory leaf-spring rear suspension.
• Spring perches are supplied unwelded. The installer must establish the correct perch spacing and pinion angle before welding.
• This fully assembled axle is not intended to have additional 3-link or 4-link suspension bracketry welded to it.
• 4-Cyl and V6 option labels identify Toyota third-member / differential style, not the engine installed in the vehicle.
• Choose axle width based on the intended vehicle, wheel/tire package, and suspension setup. Rock Assault rear housings are offered in 58-inch and 60-inch wheel-mount-surface widths.
• To obtain the housing's full differential ground clearance, the bottom of the differential housing flange must be ground flush with the axle housing.
• Professional axle setup, fabrication, and welding are recommended.

Product Specifications

Brand: Trail-Gear
Series: Rock Assault
Product Type: Fully Built Rear Axle Assembly
Position: Rear
Axle Spline: 30-Spline
Housing Tube OD: 3 in.
Housing Tube Wall: 5/16 in.
Available Wheel-Mount-Surface Widths: 58 in. / 60 in.
Suspension Mount: Bare / Leaf-Spring Perches Require Welding
Gear Ratios: 4.88 / 5.29
Locker Options: Spool / Grizzly / Zip Air Locker / ARB / Detroit
Warranty: 12-Month Limited Warranty

Installation & Ring-and-Pinion Break-In

• Confirm the selected axle width, Toyota third-member style, gear ratio, and locker before installation.
• Position and weld the leaf-spring perches for the vehicle and required pinion angle.
• Fill the differential with the correct gear oil before operation.
• After installation, drive lightly for 20–30 minutes, then allow the differential to cool for at least two hours.
• Avoid heavy throttle during the first 500 miles.
• Do not tow during the first 500 miles.
• Change the differential oil after the first 500 miles.

Available Configurations

Width

• +2 Width
• IFS Width

Third Member & Ratio

• 4-Cyl / 4.88
• 4-Cyl / 5.29
• V6 / 4.88
• V6 / 5.29

Locker

• Spool
• Grizzly
• Zip Air Locker
• ARB
• Detroit