Operation diagram of a five-speed gearbox (VAZ-2106)

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The five-speed gearbox is based on the four-speed gearbox, so the torque transmission patterns from the primary shaft to the secondary shaft in all forward gears, except for fifth gear and reverse, are similar to those of the four-speed gearbox. That is, the torque from the engine crankshaft is transmitted through the clutch to the primary shaft 1 and through gears 3 and 39 of constant engagement to the intermediate shaft. The block of gears of the intermediate shaft has constant engagement with gears 7, 8, 11 of the third, second and first gears of the secondary shaft. Therefore, they rotate from the intermediate shaft both with the gear engaged and disengaged. In addition, the block of 28 gears rotates together with the intermediate shaft, from the large crown of which the rotation is transmitted to gear 17 of the fifth gear. Since gears 7, 8, 11, 17 are loosely mounted on secondary shaft 2, when the gear shift lever is in neutral position, none of these gears transmit torque to the secondary shaft.

When starting the car from a standstill and overcoming difficult sections of the road, 1st gear is engaged (see diagram of the movement of the gear shift lever 16). In this case, the sliding clutch 9, engaging with the toothed ring of the synchronizer of gear 11 of the first gear, connects the hub 32 with gear 11. The torque from gear 11 through the clutch 9 and hub 32 is transmitted to the secondary shaft 2. The transmitted torque increases in accordance with the gear ratio of the first gear.


With further acceleration of the car, they switch from first to second gear. In this case, clutch 9 connects hub 32 with the toothed rim of gear 8 of the second gear, and the torque from gear 8 through clutch 9 and hub 32 is transmitted to the secondary shaft. The torque value decreases slightly and, compared to direct transmission, will be increased by 2.1 times, the speed of the car increases.

When shifting to third gear, sliding clutch 5 of another synchronizer connects hub 37 with the ring gear 7. Torque is transmitted from gear 7 through clutch 5 and hub 37 to secondary shaft 2. The magnitude of torque decreases slightly, and the speed increases.

When the fourth gear is engaged, clutch 5 engages with toothed ring 4 of the drive shaft, i.e. it directly connects the primary and secondary shafts of the gearbox. In this case, the rotation speed of the primary and secondary shafts will be the same, and the torque value does not change. This transmission is called direct.

When the fifth gear is engaged, the sliding clutch 14 connects the hub 13 with the toothed ring of the pinion 17. The torque will be transmitted from the primary shaft 1 through the constant mesh gears 3 and 39 to the intermediate shaft. From it to the block of 28 gears and from the large ring of the block to the driven gear 17 of the fifth gear, then through the clutch 14 and the hub 13 to the secondary shaft 2. In this case, the torque value will be minimal and the speed will be maximal.

The reverse gear is engaged by moving the gearshift lever to the right, then pressing it down and moving it backwards in the direction of the vehicle. In this case, the intermediate gear 27 of the reverse gear engages with the small ring 26 of the gear block and with the ring of the gear 12 of the reverse gear. When moving the intermediate gear 27, the head of the rod presses on the ball of the switch rod 25 and presses it in. The circuit of the reverse light lamp closes and signals in white that the reverse gear is engaged.

When the gear is engaged, when the secondary shaft 2 rotates, the rotation is transmitted to the leading gear 20 of the speedometer drive. From it, the rotation is transmitted to the driven gear of the speedometer drive and through a pair of helical gears to the speedometer cable drive shaft; the cable operates the speedometer.

The gearbox parts are lubricated with transmission oil, which is poured in the amount of 1.55 liters. When the shafts and gears rotate, an oil mist is formed. Oil through radial holes in driven gears 7, 8, 11 and 17 goes to the landing belts of the secondary shaft, on which these gears are located. Due to the grooves on these belts, an oil film is formed, preventing direct contact of the metal surfaces of the gears and the shaft.

The tightness of the gearbox housing is ensured by the primary and secondary shaft seals and the sealing gaskets that are installed between the housing and the lower and rear covers. To reduce the oil pressure on the secondary shaft seal, an oil deflector washer 19 is installed on the shaft.

The axial forces that arise when transmitting torque through helical gears are absorbed by the ball bearings of the shafts, which are fixed in their seats by mounting rings (secondary shaft intermediate bearing with locking plate), and on the shafts with spring washers and retaining rings.

The simple design of the gearbox, helical gears of constant engagement and synchronizers ensure long-lasting and silent operation of the gearbox. Its maintenance is reduced to a minimum: checking the level and changing the oil.