Cusco Rear Differential Cover 965 008 AS Instruction Manual

1. Introduction

This manual provides comprehensive instructions for the installation, maintenance, and troubleshooting of the Cusco Rear Differential Cover, model 965 008 AS. This product is specifically designed to enhance the performance and longevity of the rear differential in Subaru BRZ and Scion FR-S vehicles by increasing oil capacity and improving heat dissipation. Please read this manual thoroughly before proceeding with installation or use.

2. Safety Information

• Always ensure the vehicle is securely supported on jack stands on a level surface before working underneath. Never rely solely on a jack.
• Wear appropriate personal protective equipment, including safety glasses and gloves, during installation.
• Allow the differential to cool completely before beginning work to avoid burns from hot fluids or components.
• Dispose of old differential fluid responsibly according to local regulations.
• If you are unsure about any step of the installation process, consult a qualified automotive technician.
• Keep all tools and small parts organized to prevent loss or accidents.

3. Package Contents

Please verify that all components are present and undamaged before beginning installation. The package should contain:

• Cusco Rear Differential Cover (Model: 965 008 AS)
• Mounting hardware (bolts, washers)
• Gasket or sealing compound (may be included or sold separately, check product packaging)
• Drain and fill plugs

If any items are missing or damaged, please contact your retailer immediately.

4. Installation Instructions

Estimated Installation Time: 1-2 hours (may vary based on experience and tools)

Tools Required:

• Socket wrench set
• Torque wrench
• Drain pan
• Gasket scraper or wire brush
• Brake cleaner or degreaser
• New differential fluid (refer to vehicle manufacturer specifications)
• Fluid pump or syringe

Step-by-Step Guide:

1. Prepare the Vehicle: Safely lift and support the vehicle on jack stands. Ensure the vehicle is stable.
2. Drain Differential Fluid: Place a drain pan beneath the differential. Remove the drain plug from the bottom of the existing differential cover and allow all fluid to drain completely.
3. Remove Old Differential Cover: Once the fluid has drained, remove all bolts securing the factory differential cover. Carefully pry the cover away from the differential housing. Be prepared for any residual fluid.
4. Clean Sealing Surfaces: Thoroughly clean both the differential housing's mating surface and the new Cusco cover's mating surface. Remove all traces of old gasket material, RTV sealant, and fluid. Use a gasket scraper and brake cleaner for best results. Ensure surfaces are dry and free of oil.
5. Install New Cusco Cover:
   

   This image displays the Cusco Rear Differential Cover, model 965 008 AS. It is a silver-colored, cast aluminum component featuring prominent cooling fins on its exterior surface, designed to dissipate heat more effectively. The cover includes multiple bolt holes for secure attachment to the differential housing and threaded ports for fluid filling and draining, as well as sensor or cooler line connections.
   Apply a thin, even bead of RTV silicone sealant (or install the gasket if provided) to the sealing surface of the new Cusco differential cover. Carefully position the new cover onto the differential housing, aligning the bolt holes. Install all mounting bolts and hand-tighten them.
6. Torque Bolts: Following a crisscross pattern, gradually tighten the bolts to the vehicle manufacturer's specified torque for differential cover bolts. Refer to your vehicle's service manual for exact torque specifications. Over-tightening can damage the cover or housing, while under-tightening can lead to leaks.
7. Refill Differential Fluid: Remove the fill plug from the new Cusco cover. Using a fluid pump or syringe, fill the differential with the recommended type and amount of new differential fluid. Fill until the fluid level reaches the bottom edge of the fill hole. Reinstall the fill plug and tighten it to specification.
8. Check for Leaks: Lower the vehicle. Start the engine and allow it to run for a few minutes. Check for any leaks around the differential cover. Drive the vehicle for a short distance and re-check for leaks. Address any leaks immediately.

5. Operation and Initial Use

Once installed, the Cusco Rear Differential Cover operates passively by increasing the differential's oil capacity and enhancing heat dissipation through its finned design. No specific operational steps are required beyond ensuring proper fluid levels and monitoring for leaks after installation.

• Initial Drive: After installation, drive the vehicle gently for the first few miles.
• Post-Installation Check: Re-check the differential cover for any signs of leaks after the first drive and again after approximately 50-100 miles.
• Fluid Level: Periodically check the differential fluid level, especially after spirited driving or track use, to ensure it remains at the correct level.

6. Maintenance

Regular maintenance ensures the longevity and optimal performance of your differential and the Cusco cover.

• Fluid Changes: Adhere to your vehicle manufacturer's recommended differential fluid change intervals. The increased capacity of the Cusco cover may allow for slightly extended intervals, but always prioritize the manufacturer's guidelines or consult a specialist for performance applications.
• Leak Inspection: Periodically inspect the differential cover and surrounding area for any signs of fluid leaks. Address any leaks promptly to prevent damage to the differential.
• Cleaning: Keep the exterior of the differential cover clean, especially the cooling fins, to ensure efficient heat dissipation.

7. Troubleshooting

Most issues related to a differential cover are installation-related.

• Fluid Leaks:
  • Cause: Improperly torqued bolts, damaged gasket/sealant, debris on mating surfaces.
  • Solution: Re-check bolt torque. If leaks persist, drain fluid, remove cover, clean surfaces thoroughly, apply new sealant/gasket, and re-install with correct torque.
• Unusual Noises from Differential:
  • Cause: Incorrect fluid level, incorrect fluid type, or pre-existing differential issue. The cover itself is unlikely to cause noise.
  • Solution: Verify fluid level and type. If noises persist, consult a qualified mechanic as it may indicate an internal differential problem.

8. Specifications

9. Warranty and Support

For information regarding the product warranty, please refer to the documentation included with your purchase or visit the official Cusco website. For technical support or assistance with installation, please contact your authorized Cusco dealer or the manufacturer directly. Ensure you have your product model number (965 008 AS) and purchase details available when contacting support.

Cusco Official Website: www.cusco.co.jp/en/