2. Place a drain container of a suitable volume under the differential.
3. Remove the drain plug from the bottom of the differential housing (see illustration) and drain the oil into the prepared container.
4. After the oil has stopped flowing, feel the plug for metal filings adhered to it, then wipe it, screw it into place and tighten it firmly.
Note. The presence of sawdust on the plug indicates wear on the internal components of the assembly, the condition of which should be checked at the earliest opportunity.
5. Remove the filler / control plug from the box crankcase (see Section Checking the differential lubrication level). And using a hand pump, syringe or funnel, fill the differential with the required amount of fresh oil of the required grade - the oil level should reach the lower cut of the hole.
6. Screw the plug back into place and tighten firmly. Lower the car to the ground.
7. Drive the vehicle for a short drive and then check the differential oil level again.