The five-speed gearbox has a three-shaft layout
Crankcase of the gearbox is made of aluminum alloy and consists of two parts - front 23 and rear 1.
To ensure the alignment of the shaft supports and the holes for the rods of the shifting mechanisms, the crankcases are centered with locating sleeves pressed into the front crankcase.
The front and rear crankcases are interconnected by ten bolts 6.
For tightness, a paronite gasket 10 0.33 mm thick is installed between the crankcases.
Input gear 30, as well as 1st, 2nd, 3rd, 5th and reverse gears are in constant engagement with the 5 gear set.
These gears are helical and rotate on 20 needle bearings with plastic cages.
Reverse intermediate gear 14 rotates on bulk rollers Ø 3 mm on axle 12, the supports of which are mounted in both crankcases with bolts 11 and 16.
Forward and reverse gears are equipped with inertial synchronizers.
The axial movements of the parts of the output shaft 2 are limited by the retaining rings 34 and 74, the thrust ring 72, the two thrust half rings 22 held by the retaining ring 43, and the shoulder of the secondary shaft.
The input shaft ball bearing is fixed on the shaft with circlips 27 and in the crankcase - 26.
Rear bearing 75 of the secondary shaft is also fixed with a circlip.
Gear unit 5 rotates on ball bearings 4 installed in the seats of the front and rear of the crankcases.
The axial clearance of the gear block is adjusted during assembly by selecting the thickness of the package of adjusting rings 24 installed in the seat of the front crankcase.
The rims of the gear unit 5 are installed with an interference fit on the intermediate shaft.
The locking device of the gear change mechanism consists of two locking plungers 66 and a locking pin 65.
A locking sleeve with a spring is provided against accidental engagement of reverse gear.
The shift rods are fixed with balls 50 loaded with springs 51.
The shift leveris equipped with a damping device that eliminates vibration at high crankshaft speed.
The tightness of the gearbox is ensured by three oil seals, one of which (pos. 28) is installed on the input shaft in the input shaft bearing cap 30, and the other two (pos. 77) are in the extension of the rear crankcase.
The oil drain plug is equipped with a magnet to trap metal products of gearbox wear.