1. Park the car on level ground and allow the engine to cool down.
2. Locate the filler plug on the gearbox. It is usually located on the side of the gearbox, near the bottom. The filler plug is usually marked with a "P" or "OIL" label.
3. Remove the filler plug using a suitable Allen wrench.
4. Insert a clean dipstick into the filler hole and measure the oil level. The oil level should be between the "MIN" and "MAX" marks on the dipstick.
5. If the oil level is low, add enough oil to bring it up to the "MAX" mark. Use the recommended type of oil specified in the owner's manual.
6. Replace the filler plug and tighten it securely.
Note: If the gearbox oil is low, it is important to check for any leaks and have them repaired as soon as possible. Low gearbox oil can cause damage to the gearbox.
The process of changing the gearbox oil in a Peugeot 407 is more involved and requires specialized tools and knowledge. It is recommended to have this service performed by a qualified mechanic.
