We check the oil level on a cooled gearbox, placing the car on a flat horizontal surface.

Using a 13 mm socket, unscrew the inspection hole plug in the gearbox housing…

…and we remove the plug from the hole.
With a normal amount of oil in the gearbox, its level should reach the lower edge of the inspection hole - check with your finger. If the oil level is significantly lower than required, then you need to add oil to the gearbox. You can add oil from below the car - through the inspection hole using a special syringe for transmission oil or from above - through the hole in the gearbox housing for the breather using a funnel.
To add oil from above, in the engine compartment..

…we use a 17 mm wrench to loosen the breather…

and turn off the breather.

We insert a funnel into the gearbox crankcase breather hole…

…and fill with transmission oil until it starts pouring out through the inspection hole.
We tighten the plug of the inspection hole.
Before installing the breather, check the condition of its holes. To do this, remove the cap from the breather.

If the breather holes are clogged with dirt, clean them.
We wrap the breather and close it with a cap.
