The final drive of the driving axles is shown in Figure 1.
One of the characteristic signs indicating the need to disassemble and adjust the gearbox is increased noise when the car is moving.
Reason for increased noise:
- - displacement of the contact patch in the engagement of bevel gears as a result of a violation of the adjustment of the conical bearings;
- - scoring and chipping of gear teeth, wear of bearings, as well as insufficient oil level in the axle housing.
The drive axles of the vehicle are of the through type, with the top location of the main gear.
The main gear of the bridge is double, it consists of a pair of bevel gears 1 and 14 (Fig. 3) with helical teeth and a pair of cylindrical gears 4 and 29 with oblique teeth.
A symmetrical bevel differential with four satellites is bolted to the driven spur gear.
Depending on the technical requirements for the car, the main gears have gear ratios of 7.32; 6.7; 8.9 and 8.05.
To distinguish the main gears, they are marked with plates with the gear ratio designation, installed under the bolt of the cover of the cup of the bearings of the driving spur gear.
Final gears with a gear ratio of 8.9 do not have marking plates.
The main gears are distinguished by marks on the driving and driven cylindrical gears (see table)
The main gear is installed on the crankcase of the bridge 10 (Fig. 4) through the sealing paronite gasket 9 with a thickness of 0.8 mm and fastened with eleven bolts and two studs.
Eleven bolts and studs are installed outside, and two bolts are installed in the cavity of the bevel gears.
Internal bolts can only be accessed after removing the side cover 6.
Spring washers are installed under the outer bolts and nuts of the studs.
Internal bolts are cottered with wire.
Fig. 5
The gears and bearings of the final drive are lubricated with oil poured into the axle housing and final drive housing to the level of the control hole.
The oil is picked up by the gears, sprayed and through the roller bearing 2 (see Fig. 3) enters the cavity of the bevel gears of the final drive housing, from where it flows into the axle housing.
The drive bevel gear bearings are lubricated with oil from the cavity of the bevel gears, which is fed into the bearing cup through the pocket on the crankcase cover and the oil supply fitting.
The main gears of the front and rear axles differ from the main gears of the middle axle by drive flanges.
A bushing 21 with a cover 22 is installed on the front end of the drive gear shaft of the front axle, and a flange 18 is installed on the rear end.
The main gear of the rear axle has one flange on the side of the drive bevel gear.
The opposite end of the pinion shaft may not have splines.
Crankcases 10 (see Fig. 4) of the bridges are combined, they consist of a cast middle part and tubular casings of the axle shafts pressed into it.
The axle shafts are fully unloaded, the connection between the axle shaft and the hub is splined.
The front axle of the car is the leading steerable. The design of the pivot assembly of the front drive axle is shown in fig. 5.
The torque to the front drive wheels is transmitted through the axle shafts and joints of equal angular velocity (рis. 6).
For reliable and durable operation of drive axles, use oils according to the chemotological map and maintain the required level in the crankcases.
To change the lubricant in the hinges of the front axle axle shafts, remove the wheel, brake drum with hub, brake shield, pivot pin. Remove grease and wash the CV joint parts.
Regularly check the tightening of the bolts securing the final drive to the axle housing.
Loosening the bolts causes the crankcase to bend.
Changing the oil in the crankcases of drive axles and checking its level
Clean the drive axle housing from dust and dirt.
Unscrew plug 3 (Fig. 7) of the control hole and drain plug 4 in the crankcase, drain the oil (it is advisable to drain it immediately after the car stops, when it is still warm).
Put the drain plug back on. Unscrew hose 5 from fitting 2 of the sealing system, clean it with a wire brush and wrap it.
Rinse the crankcase of the bridge, pouring 1.5 ... 2 liters of low-viscosity oil into it.
Drain the low-viscosity oil and fill the crankcase with 13.5 liters of clean transmission oil TSp-15k (MT-16p).
Oil should be changed in turn in all drive axles.
Check the oil level in the drive axle by removing the oil level plug.
The oil should be at the level of its lower edge.
The filler hole, closed with plug 1, is used when filling the axle with oil after changing the bevel gears.
Check the tightness of the connections and the absence of oil leakage.
Tighten the bolts 1 (fig. 8) of the gearbox mounting, bolts 2 and 3 of the through shaft caps and bolts of 4 cups of the main gear bearings. On the surface of the crankcase and in the places of the connectors there should be no traces of oil leakage.
Lubrication of front axle axle joints and lower pivot bearings
Unscrew the plug 1 (fig. 9) of the filler hole of the steering knuckle housing and check the presence of grease. It should be at the level of the filler hole.
If the level is insufficient, add a heated mixture consisting of 50% AM grease (cardan) and 50% TSp-15k and pour into the steering knuckle housing to the specified level.
Tighten the cork.
To change the lubricant in the constant velocity joints of the front drive axle, disassemble the joints, remove the old grease, and wash the parts of the joints.
Pour fresh grease directly into the ball joints.
Lubricate the upper bearings of the pivots through the oiler 2 using a syringe press.