Longfield 30-Spline Birfield & Axle Kit | 4WD Solid Axle (1984-95 4Runner / 1979-95 Pickup)

Longfield 30-Spline Birfield & Axle Kit

For 1984–1995 Toyota 4Runner and 1979–1995 Toyota Pickup 4WD with Toyota-Style Solid Front Axle

Overview

The Longfield 30-Spline Birfield & Axle Kit is a heavy-duty front axle upgrade for Toyota-style solid axle applications. The kit replaces the factory-style 27-spline birfield and axle arrangement with 30-spline Longfield birfields and 4340 chromoly axle shafts.

The birfield housings are forged from 4340 chromoly steel, with heat-treated 4340 chromoly internals and precision-polished surfaces designed to reduce imperfections that can create stress risers under heavy loads.

The kit fits factory solid-axle Toyota trucks through 1985 and 1986–1995 Toyota 4Runner and Toyota Pickup solid axle conversions using the appropriate Toyota-style solid front axle housing. Standard-width, +3-inch, and +5-inch configurations support factory-width and widened axle builds.

Key Features

• 30-spline Longfield birfields
• Forged 4340 chromoly birfield housings
• Heat-treated 4340 chromoly birfield internals
• 4340 chromoly axle shafts
• Precision-polished birfield construction
• Rated approximately 76% stronger than stock axles
• Up to 40 degrees of birfield steering angle
• Rated breaking point of approximately 8,900–9,000 ft-lbs
• Standard-width, +3-inch, and +5-inch axle configurations
• 12-month limited warranty

Vehicle Fitment

Toyota 4Runner — 1st Gen — 4WD

• 1984–1985: Factory solid front axle
• 1986–1989: Toyota-style solid axle conversion

Toyota 4Runner — 2nd Gen — 4WD

• 1990–1995: Toyota-style solid axle conversion

Toyota Pickup — 1st Gen — 4WD

• 1979–1983: Factory solid front axle

Toyota Pickup — 2nd Gen — 4WD

• 1984–1985: Factory solid front axle
• 1986–1988: Toyota-style solid axle conversion

Toyota Pickup — 3rd Gen — 4WD

• 1989–1995: Toyota-style solid axle conversion

Fitment Notes

• 4WD solid front axle applications only
• 1984–1985 4Runner / 1979–1985 Pickup applications use the factory Toyota solid front axle
• 1986–1995 applications require a Toyota-style solid axle conversion
• Fits Toyota solid front axle housings
• Fits Trail-Gear Rock Assault front axle housings
• Does not fit the factory Toyota IFS front suspension
• Upgrades the factory-style 27-spline birfield and axle arrangement to 30-spline components
• Select the axle width that matches the front axle housing being used
• Standard Width is designed for factory-width solid axle applications
• +3" and +5" configurations require corresponding widened solid axle setups

Product Specifications

Brand: Longfield
Product Type: Front Birfield & Axle Kit
Position: Front
Axle Type: Toyota-Style Solid Front Axle
Birfield Spline Count: 30-Spline
Birfield Housing Material: Forged 4340 Chromoly Steel
Birfield Internal Material: 4340 Chromoly Steel
Axle Shaft Material: 4340 Chromoly Steel
Birfield Heat Treatment: Single Heat-Treated
Maximum Steering Angle: Up to 40 Degrees
Rated Breaking Point: Approximately 8,900–9,000 ft-lbs
Warranty: 12-Month Limited Warranty

Which Longfield Axle Package Should You Choose?

30-Spline Birfield & Axle Kit — Best for a Lower-Cost Birfield and Shaft Upgrade

The kit combines single heat-treated 30-spline birfields with 4340 chromoly axle shafts for builds that do not need the additional Super Set components or gun-drilled features.

Gun-Drilled Birfield & Axle Super Set — Best for a More Complete Axle and Hub Upgrade

The Super Set adds dual heat-treated birfields, gun-drilled grease access, Machined Spline Savers, chromoly inner and outer hub gears, Creeper Drive Flanges, and a lifetime warranty for the original purchaser.

Our Recommendation: Choose the Birfield & Axle Kit when you primarily need replacement birfields and shafts. Choose the Gun-Drilled Super Set when your build also needs its hub components and lubrication features, selecting the axle width and hub configuration to match your solid-axle setup.

Available Configurations

Standard Width

Includes:

• (2) Longfield 30-spline birfields
• (1) short-side and (1) long-side 4340 chromoly axle shaft for the standard-width configuration

For standard-width Toyota-style solid front axle applications.

+3" Width

Includes:

• (2) Longfield 30-spline birfields
• (1) short-side and (1) long-side 4340 chromoly axle shaft for the +3-inch-width configuration

For +3-inch-width Toyota-style solid front axle applications.

+5" Width

Includes:

• (2) Longfield 30-spline birfields
• (1) short-side and (1) long-side 4340 chromoly axle shaft for the +5-inch-width configuration

For +5-inch-width Toyota-style solid front axle applications.