Yukon Gear Master Differential Overhaul Kit | Toyota 8" 4-Cylinder 4WD (1984-85 4Runner / 1979-85 Pickup)

Yukon Gear Toyota 8" 4-Cylinder Master Differential Overhaul Kit

For 1984–1985 Toyota 4Runner and 1979–1985 Toyota Pickup 4WD with the early Toyota 8" 4-cylinder differential

Overview

The Yukon Gear Master Differential Overhaul Kit provides the bearings, races, seals, shims, and setup hardware needed to rebuild the early Toyota 8-inch 4-cylinder differential used in solid-axle Toyota 4WD applications. On 1979–1985 4WD trucks and 1984–1985 4Runners, this differential is used at the front and rear, so the kit can be configured for either axle position when the installed third member matches the early Toyota 8-inch 4-cylinder design.

The kit uses premium Timken bearings and races with application-specific seals and setup components. Available configurations cover factory-style 27-spline pinions, aftermarket 29-spline gearsets, 45 mm or 50 mm carrier-bearing journals, and either a conventional crush sleeve or solid pinion spacer.

Key Features

• Master overhaul kit for the early Toyota 8" 4-cylinder differential
• Fits applicable front and rear differential positions on the listed 4WD vehicles
• Premium Timken bearings and races
• Supports factory-style 27-spline and aftermarket 29-spline pinion configurations
• Available for 45 mm and 50 mm carrier-bearing journals
• 45 mm configuration fits the original-style 4-cylinder carrier and applicable 45 mm-journal lockers
• 50 mm configuration supports applicable ARB, Yukon Zip, and V6-style 50 mm-journal lockers in the early 4-cylinder third member
• Choice of standard crush-sleeve preload or solid pinion-spacer setup
• Suitable for differential rebuilds, gear-ratio changes, and locker installations

Configuration Guide

27-Spline – Factory Ring & Pinion

Select this configuration when retaining the factory-style 27-spline pinion.

29-Spline – Aftermarket Ring & Pinion

Select this configuration when using a corresponding aftermarket Toyota 8-inch 29-spline ring-and-pinion set. The required 29-spline conversion yoke, seal, and pinion nut are not supplied by the overhaul kit itself and must be matched to the selected gearset.

45 mm Carrier – OEM / 45 mm-Journal Locker

Select the 45 mm configuration for the original-style 4-cylinder differential carrier or a locker using 45 mm carrier-bearing journals.

50 mm Carrier – ARB / Yukon Zip / V6-Style Locker

Select the 50 mm configuration when installing an applicable locker or carrier with 50 mm bearing journals into the early 4-cylinder third member.

Standard Crush Sleeve

Uses the conventional crush-sleeve method to establish pinion-bearing preload.

Solid Pinion Spacer Upgrade

Uses a solid spacer and shims to establish pinion-bearing preload in place of the conventional crush-sleeve setup.

Master Kit Contents

• Carrier bearings and races
• Pinion bearings and races
• Pinion seal
• Complete differential shim kit
• Ring gear bolts
• Pinion nut
• Crush sleeve or solid pinion-spacer configuration
• Oil baffles and slingers as applicable
• Thread-locking compound
• Gear-marking compound and brush
• Differential gasket
• Application-specific small parts

Carrier bearings vary according to the selected 45 mm or 50 mm carrier-bearing configuration.

Vehicle Fitment

Toyota 4Runner

• 1984 Toyota 4Runner – 1st Gen – 22R – 4WD – Toyota 8" 4-Cylinder Front / Rear Differential
• 1985 Toyota 4Runner – 1st Gen – 22R / 22RE – 4WD – Toyota 8" 4-Cylinder Front / Rear Differential

Toyota Pickup

• 1979–1980 Toyota Pickup – 1st Gen – 20R – 4WD – Toyota 8" 4-Cylinder Front / Rear Differential
• 1981–1983 Toyota Pickup – 1st Gen – 22R – 4WD – Toyota 8" 4-Cylinder Front / Rear Differential
• 1984–1985 Toyota Pickup – 2nd Gen – 22R / 22RE – 4WD – Toyota 8" 4-Cylinder Front / Rear Differential

Fitment Notes

• Toyota 8" 4-cylinder differential only.
• Applicable to the front and rear third members on the listed factory solid-axle 4WD vehicles.
• Select 27-spline for the factory-style ring and pinion.
• Select 29-spline for the matching aftermarket 29-spline ring-and-pinion configuration.
• Select 45 mm carrier bearings for the original-style carrier or applicable 45 mm-journal locker.
• Select 50 mm carrier bearings for applicable 50 mm-journal ARB, Yukon Zip, or V6-style locker carriers.
• Carrier-bearing journal size and pinion spline count are separate specifications and must both match the installed parts.
• Does not fit the later Toyota V6/Turbo-style 8-inch third member.
• Does not fit Toyota 7.5-inch differentials.
• Toyota third members are commonly swapped; verify the installed differential before ordering.
• Proper bearing preload, backlash, and gear-contact pattern must be established during installation.
• Professional differential setup is recommended.

Product Specifications

Brand: Yukon Gear & Axle
Product Type: Master Differential Overhaul Kit
Differential: Toyota 8" 4-Cylinder
Position: Front / Rear
Drivetrain: 4WD
Bearing Type: Tapered Roller
Bearing Brand: Timken
Pinion Options: 27-Spline / 29-Spline
Carrier Journal Options: 45 mm / 50 mm
Pinion Preload Options: Crush Sleeve / Solid Pinion Spacer
Installation: Professional Differential Setup Recommended

Ring & Pinion and Overhaul Options

A differential rebuild should use parts matched to the third-member generation, pinion spline, carrier-bearing size, and chosen gearset. Yukon Gear 4.88 Ring & Pinion Gear Set | Toyota 8" 4-Cylinder — aftermarket 29-spline gearset option. Yukon Gear 5.29 Ring & Pinion Gear Set | Toyota 8" 4-Cylinder — lower-ratio aftermarket 29-spline gearset option. Yukon Gear Master Differential Overhaul Kit | 1986–1995 Toyota 8" 4-Cylinder — corresponding later third-member overhaul listing.

Available Configurations

Pinion Spline Configuration

• 27-Spline (Factory Ring & Pinion)
• 29-Spline (Aftermarket Ring & Pinion)

Carrier Bearing Configuration

• 45mm Carrier (OEM / 45mm-Journal Locker)
• 50mm Carrier (ARB / Yukon Zip / V6-Style Locker)

Pinion Spacer Configuration

• Standard Crush Sleeve
• Solid Pinion Spacer Upgrade