Before proceeding to check the technical condition, check the oil level in the gearbox (see below, "Gearbox - oil level check"). In a box operated with a low oil level in the crankcase, intensive wear of parts occurs and it may soon fail. On the inspection hole or overpass, we inspect the gearbox from all sides, make sure that there are no oil leaks at the junctions of the crankcases and the cover, as well as through the oil seals of the wheel drives and the gear selector rod. We are convinced of the serviceability and correct adjustment of the clutch release mechanism (see "Clutch - checking the technical condition").
By pressing the clutch pedal, we turn on all the gears in turn, check the clarity of their inclusion and deactivation. If necessary, adjust the gearshift mechanism (see "Gearshift drive - removal, installation and adjustment").
Set the gear lever to neutral position and start the engine. After pressing the clutch pedal several times, we listen to the sound of the operation of the gearbox bearings. It appears when the clutch pedal is released and disappears when it is pressed. The loud noise of the bearings indicates wear.
We check the operation of the gearbox in motion. To do this, moving first with acceleration, and then with deceleration, we shift gears with an increase, and then with a decrease. We check the clarity of switching on and off gears, the operation of synchronizers while driving. We make sure that there are no crunches, knocks and other extraneous sounds during the operation of the box, as well as spontaneous disengagement of gears when the load changes.