The cars are equipped with a mechanical, five-speed, three-shaft gearbox with a fifth overdrive
A four-speed gearbox, previously installed on Volga cars GAZ-24, GAZ-3102 and -31029, can be installed on parts of cars with a ZMZ-402 engine.
The five-speed gearbox is unified in most parts with the gearbox installed on cars of the Gazelle and Sobol families.
Differences in the gearbox of the Volga car are in smaller gear ratios in all gears except the fourth, as well as in a lower shift lever housing and its shortened lower end.
The gearbox housing consists of two parts - the front and rear housings, cast from aluminum alloy and connected through a gasket with ten bolts in a plane perpendicular to the axis of the shafts.
To ensure the alignment of the bearing seats and the holes for the shift rods, the crankcases are centered with each other through the locating sleeves.
In the bores of the crankcases on radial ball bearings, the primary, secondary and intermediate shafts with helical gears of constant mesh are installed.
The gears of the secondary shaft are placed on roller (needle) bearings with plastic cages.
The gears of the second, third, fifth gears and the intermediate shaft drive are pressed onto the intermediate shaft and form a gear block.
The teeth of the gears of the first gear and at the same time the reverse gear are cut directly on the intermediate shaft.
The helical reverse counter gear receives constant rotation from the countershaft when driving in all gears and the shift lever is in neutral.
It is supported by a roller bearing on a fixed axle attached to both crankcases.
All gears are equipped with inertial synchronizers. Their ring gears are connected to the gears through small splines.
The switching mechanism consists of rods with forks and heads, in the grooves of which the lower end of the switching lever is located.
Fixation of the included gears is carried out by spring-loaded balls.
The locking device, consisting of two plungers and a locking pin, prevents the inclusion of two gears at the same time.
The shift lever is equipped with a damper device that prevents it from trembling (resonance) at high engine speeds.
The splined rear end of the output shaft is connected to the sliding yoke of the driveline.
The fork shank enters the steel-babbit bushing of the extension of the rear gearbox housing and, moving in this bushing and along the splines of the output shaft, compensates for the axial travel of the driveline when the rear suspension is operating.
A leading helical gear for the speedometer sensor drive is installed on the secondary shaft.
For filling and draining oil, filler and drain plugs with tapered self-sealing threads are used.
The drain plug has a magnet to catch transmission wear products. Filler plugs are located on both sides of the crankcase.
Difficulty shifting
Incomplete clutch disengagement due to a malfunction of the clutch release hydraulic drive - Clutch hydraulic repair
Loosen the torque of the stop bolts securing the forks to the stems - Tighten the stop bolts
Burrs on the teeth of the synchronizer sliding sleeves - Clean the burrs
Uneven wear on pin holes in shift lever housing - Replace shift lever housing
Forward gear shifting out of sync
Wear of the cone of the synchronizer blocking ring - Check the axial clearance.
If necessary, replace the blocking ring by grinding it against the gear surface
Deformation of the synchronizer blocking ring - loose fit of the ring on the cone - Replace the blocking ring by rubbing it against the surface of the gear
Worn bevels of the teeth of the blocking ring or synchronizer sleeve - Replace the blocking ring or synchronizer sleeve
Spontaneous deactivation
Loosen the fasteners of the gearbox to the clutch housing or the clutch housing to the cylinder block - Tighten the fasteners
Wear of the teeth of the side surfaces of the sliding sleeves of the synchronizers or wear of the teeth of the gears - Replace defective parts
Loss of elastic properties of retainer springs - Replace springs
Increased noise in the gearbox
Worn gear teeth - Replace defective gears
Worn bearings - Replace defective bearings
Low oil level in the gearbox housing - add oil to the required level
Oil leaking from gearbox
Increased pressure in the gearbox housing due to a dirty breather - Clean or replace the breather
Worn seal lips - Replace defective oil seals
Leaking plugs or plugs - Tighten the plugs. Install plugs and plugs on the sealant
Loose fasteners on front and rear crankcases, front cover or shift lever housing - Tighten fasteners defective or damaged gaskets on mating surfaces -
Fix mating surfaces or replace gaskets
Vibration while driving
Worn steel babbit bushing of rear gearbox housing - Replace rear gearbox housing
When any gear is engaged, torque is not transmitted to the drive wheels
Loose seat of gears on countershaft - Replace gear set