The quality of the produced gear oils and the perfection of the transmission design of a modern car make it possible not to change the oil in a manual gearbox during the entire service life of the unit. It is also not required to check the transmission oil level of a manual transmission, of course, if no oil leak is detected.
If a transmission oil leak is detected from the unit, it is necessary to eliminate the malfunction as soon as possible and bring the oil level in the gearbox housing to normal (see «Transmission - Checking the Transmission Oil Level»).
Only the recommended brand and type of gear oil should be added to the gearbox.
Need to change gear oil (see «Transmission - changing gear oil») may occur due to a violation of the operating conditions of the car, when replacing the front wheel drives and repairing the gearbox, as well as when the car has a very high mileage or a long service life.