Note: The gearbox oil level can only be checked by completely draining the transmission oil and then refilling it. To drain the transmission oil, remove the gearbox shift fork shaft journal. To prevent the shift fork position from changing, for example if the shift mechanism is accidentally activated, the gearshift rod must be secured.
Checking the oil level in the gearbox using previously known methods is now impossible.

The tilt of the engine/gearbox unit was changed, therefore the lower edge of the filler hole "1" is below the new oil level "2".

Draining transmission oil
Note: To drain the transmission oil, remove the journal of the shift fork shaft in the gearbox. To prevent the shift fork position from changing, for example if the shift mechanism is accidentally activated, the gear shift rod must be secured.
Remove the air filter if it is installed above the gearbox. Secure the gearshift rod as follows: move the gearshift lever in the direction of "arrow 1" down into the 1st/2nd gear shift channel. At the same time, turn the corner "A" in the direction of "arrow 2" so that it locks. In this case, the gearshift rod is locked and does not move anymore. Remove the lower noise-insulating engine casing. Install an oil collection pan under the gearbox.

Text obtained from the website SkodaBook.ru
Unscrew the threaded plug of the oil drain hole "1", remove the journal of the shaft "2" and drain the transmission oil. Screw in the threaded plug of the oil drain hole "1" and tighten to the specified torque. Install the support sleeve "2" (the O-ring must be replaced) and tighten to the specified torque.

Turn the square "A" to its original position in the "direction of the arrow". Install the lower noise-insulating casing of the engine.

Filling transmission oil
Remove the air filter if it is installed above the gearbox. Remove the reverse light switch "see arrow". Insert a hose with a funnel into the hole for mounting the reverse light switch and fill it with transmission oil. Install the reverse light switch "see arrow" and tighten it to the specified torque.

