1987 Toyota Supra Manual Transmission Differential

The 1987 Toyota Supra features a robust manual transmission differential system designed for optimal performance and durability. This rear-wheel drive sports car utilizes a limited-slip differential with gear ratios optimized for the 7M-GE engine. The differential assembly includes final drive gears, pinion gears, and axle shafts engineered to handle the vehicle's torque output while providing smooth power delivery and reliable traction.

1. Technical Specifications 2. Differential Components 3. Installation Procedures 4. Maintenance Schedule 5. Fluid Requirements 6. Troubleshooting Guide 7. Performance Upgrades 8. Safety Precautions 9. Warranty Information

Technical Specifications

The 1987 Toyota Supra manual transmission differential features precision engineering for optimal performance characteristics.

SpecificationDetails
Differential TypeLimited Slip Differential (LSD)
Gear Ratio3.73:1 (standard)
Case MaterialCast Aluminum Alloy
Axle Shaft Type31-spline forged steel
Ring Gear Diameter8 inches
WeightApproximately 85 lbs
Compatible TransmissionsW58 5-speed manual
Torque CapacityUp to 350 lb-ft
Lubricant Capacity1.5 quarts
Bearing TypeTapered roller bearings

Differential Components

Understanding the key components of the differential system is essential for proper maintenance and repair.

  1. Differential Case: Houses the ring gear and differential gears
  2. Ring and Pinion Gears: Transfers power from driveshaft to axle shafts
  3. Side Gears and Spider Gears: Allows wheel speed differentiation in turns
  4. Limited Slip Clutch Packs: Provides torque transfer to both wheels
  5. Axle Shafts: Connects differential to rear wheels
  6. Pinion Flange: Connects to driveshaft
  7. Bearing Preload Shims: Maintains proper bearing tension
  8. Drain and Fill Plugs: For fluid maintenance

WARNING! Differential components operate under extreme pressure; handle with care during disassembly.

Installation Procedures

Proper installation ensures optimal performance and longevity of the differential system.

  1. Vehicle Preparation: Secure vehicle on lift, remove rear wheels
  2. Driveshaft Removal: Unbolt driveshaft from pinion flange
  3. Axle Shaft Removal: Remove axle shafts from differential
  4. Differential Removal: Unbolt differential from rear subframe
  5. New Unit Installation: Position new differential, torque bolts to specification
  6. Axle Reinstallation: Install axle shafts with new seals
  7. Driveshaft Connection: Reconnect driveshaft, torque fasteners
  8. Fluid Fill: Add specified differential fluid to proper level

CAUTION! Use proper lifting equipment; differential assembly is heavy and requires secure handling.

Maintenance Schedule

Fluid Requirements

Proper lubrication is critical for differential longevity and performance.

Recommended Fluids: Toyota Genuine Differential Fluid, 75W-90 GL-5 Gear Oil, Limited Slip Differential Additive

Capacity: 1.5 quarts (1.4 liters) including limited slip additive

Change Procedure: Warm differential, remove fill plug first, then drain plug, refill until fluid runs out fill hole

Important: Always use limited slip additive with GL-5 gear oil to prevent chatter

Troubleshooting Guide

Common differential issues and their solutions for the 1987 Supra.

SymptomPossible CauseCorrective Action
Whining noiseWorn ring and pinion gearsInspect gear wear pattern, replace if necessary
Chattering in turnsInsufficient LSD additiveDrain and refill with proper LSD fluid
Fluid leaksWorn axle seals or pinion sealReplace seals, check breather tube
VibrationWorn U-joints or improper torqueCheck driveshaft U-joints, retorque fasteners
One wheel spinWorn LSD clutch packsRebuild limited slip unit
Gear oil smellOverheating differentialInstall cooler or synthetic fluid
Knocking soundWorn spider gearsRebuild differential assembly

Performance Upgrades

Enhance your Supra's differential for improved performance and durability.

  1. Gear Ratio Changes: 4.10:1 for acceleration, 3.55:1 for highway
  2. Aftermarket LSD: Torsen or clutch-type for improved traction
  3. Cooling Solutions: Differential cooler for track use
  4. Baffled Cover: Prevents oil starvation during hard cornering
  5. Solid Bushings: Reduces differential movement under load
  6. Carbon Fiber Clutches: Improved LSD engagement
  7. Bearing Upgrades: High-performance bearings for increased RPM
  8. Case Reinforcement: Welded ribs for high horsepower applications

Note: Some upgrades may require professional installation and tuning.

Safety Precautions

Critical safety measures when working with differential systems.

WARNING! Always use jack stands; never work under vehicle supported only by jack. Wear safety glasses when servicing differential. Hot differential fluid can cause severe burns. Ensure parking brake is engaged and wheels are chocked. Use proper torque specifications for all fasteners.

Warranty Information

The original differential was covered under Toyota's 5-year/60,000-mile powertrain warranty. Current replacement parts may have varying warranty coverage from manufacturers. Always retain receipts and follow maintenance schedules to preserve warranty coverage. For technical support, contact Toyota Customer Service at 1-800-331-4331 or visit www.toyota.com.

1987 Toyota Supra Manual Transmission Differential Guide © - All Rights Reserved 2025