2. Clean the surfaces adjacent to the filler plug and level gauge on the rear axle, then unscrew the plug (see Figure 30.2). The oil level may drop by 6 mm below the plug hole, but no more. The best way to check the oil level is to use a makeshift "dipstick" made from bent wire. Insert the wire into the hole (but don't drop it inside) and check the level.
Figure 30.2. Location of the filler plug and oil level check in the rear axle: A "N" is a bridge; In "G" - bridge
3. If there is not enough oil in the axle, add the required amount using a syringe or plastic tube. Make sure by referring to the section "Lubricants, liquids and containers" at the beginning of this Chapter that you are using the recommended grade of oil.
4. Replace the filler and level plug and tighten it.
5. The need for frequent replenishment of the oil level can only be caused by a leak, which must be found and corrected immediately.