When servicing the fluid on a manual trans/transaxle, what should you do?

• A. Use engine oil
• B. Use automatic transmission fluid
• C. Use gear oil
• D. Check service information for correct replacement fluid

Answer: (D)

The main idea is that the correct fluid for servicing a manual transmission is whatever the manufacturer specifies, so you must check the service information to know the exact fluid type and specification before refilling. Transmissions are designed to use specific lubricants with particular viscosities and additive packages, and using the wrong fluid can lead to worn gears, poor shifting, or clutch issues. Engine oil, generic gear oil, or automatic transmission fluid are not universally correct choices for all manuals; the only reliable approach is to verify the exact fluid recommended by the vehicle’s service information, including type, viscosity, and any special requirements. This avoids damage and ensures proper operation.