AE86 OS Giken Super Lock 1.5-Way Limited Slip Differential | 4A-GE (1983-87 Corolla)

OS Giken Super Lock 1.5-Way Limited Slip Differential

For 1983–1987 Toyota Corolla AE86

Overview

The OS Giken Super Lock 1.5-Way Limited Slip Differential is a mechanical clutch-type rear LSD for 4A-GE-powered Toyota Corolla AE86 manual-transmission applications. Its patented pressure-ring design combines low initial preload with smooth, progressive locking, allowing the differential to remain composed during normal driving while increasing lock as drivetrain load rises.

The standard AE86 specification uses a 25/38 ramp configuration, 20 friction plates, 336 lock timing, and 10S preload. Separate Zenki and Kouki versions cover the early and late AE86 production ranges, and the correct version must be matched to the vehicle's actual rear-axle configuration.

Key Features

• 1.5-way mechanical clutch-type limited slip differential
• 25/38 ramp configuration
• 20 friction plates
• 336 lock timing
• 10S preload
• Low initial preload with progressive locking under load
• Capable of progressively reaching full lock
• Spline-through-side-gear design allows a high-capacity friction-plate arrangement
• High-grade steel-alloy construction
• Chemically heat-treated drivetrain components
• Raw-forged gears
• Precision-machined clutch discs
• Billet-machined differential case
• Separate Zenki and Kouki AE86 configurations

Progressive Super Lock Design

The Super Lock design uses a pressure-ring and lock-timing system that allows relatively free differential action at light load while progressively increasing locking force as torque is applied. This helps provide smooth low-speed operation and predictable traction as power is added.

The 20-plate clutch arrangement spreads load across a large friction area, while OS Giken's standard low-preload setup is designed to provide progressive locking without relying on high static preload.

Vehicle Fitment

Zenki / Early

• 05/1983–09/1985 Toyota Corolla AE86 – 4A-GE / 4AG – Manual Transmission

Kouki / Late

• 10/1985–04/1987 Toyota Corolla AE86 – 4A-GE / 4AG – Manual Transmission

Fitment Notes

• 4A-GE / 4AG manual-transmission AE86 application only.
• Zenki / Early: for 05/1983–09/1985 production.
• Kouki / Late: for 10/1985–04/1987 production.
• Kouki / Late version is designed for OEM open-differential axle shafts only.
• Factory 4A-C / SR5 rear-axle applications are not part of OS Giken's cataloged fitment for these versions.
• If the rear axle or axle shafts have been swapped, identify the installed rear-axle configuration before ordering rather than selecting by exterior Zenki/Kouki appearance alone.
• Proper differential bearing preload, backlash, and ring-and-pinion setup are required during installation.
• Refer to the Toyota factory service procedure for differential installation specifications.
• Professional differential setup is recommended.

Product Specifications

Brand: OS Giken
Series: Super Lock
Product Type: Limited Slip Differential
Position: Rear
Differential Type: Mechanical Clutch-Type LSD
Configuration: 1.5-Way
Ramp Angles: 25/38
Total Friction Plates: 20
Lock Timing: 336
Preload: 10S
Locking Characteristic: Progressive, Up to Full Lock
Construction: High-Grade Steel Alloy
Gear Construction: Raw-Forged
Component Treatment: Chemical Heat Treatment
Case Construction: Billet-Machined
Drivetrain: RWD
Engine: 4A-GE / 4AG
Transmission: Manual

Gear Oil & Service

OS Giken recommends a differential oil formulated for the Super Lock's negative-preload design. OS Giken OS-250R V2 80W-250 LSD Gear Oil is the current OS Giken mechanical-LSD fluid and is also available bundled with this differential.

The gear-oil bundle includes 2 liters total so the required oil can be ordered with the LSD in one configuration.

Other AE86 Limited Slip Differential Options

Preserve Rad also carries the CUSCO Type RS Limited Slip Differential. Match any LSD to the installed rear-axle configuration before ordering.

Available Configurations

Zenki / Early | 05/1983–09/1985

• LSD Only – OS Giken Super Lock 1.5-Way LSD
• LSD + 2L OS-250R V2 Gear Oil – LSD plus two 1-liter cans of OS-250R V2

Kouki / Late | 10/1985–04/1987

• LSD Only – OS Giken Super Lock 1.5-Way LSD
• LSD + 2L OS-250R V2 Gear Oil – LSD plus two 1-liter cans of OS-250R V2