Maintenance of Kamaz vehicle axles
The main maintenance operations for axles are checking the tightness of the joints, lubricating the gearboxes and adjusting the bearings and gear engagement.
During maintenance, check the level and, if necessary, add oil to the crankcase of the drive axle. The oil level is checked by the control hole.
If necessary, oil can be topped up through the same hole.
The used oil is drained after the main gear has been preheated through the drain holes in the axle housing.
Before filling in fresh oil, it is necessary to flush the breathers and clean the magnets of the drain plugs from metal deposits.
In order to reduce their axial movement, the bearings of the final drive gear are installed with preload during assembly, which allows maintaining the correct meshing of the teeth of the bevel gears under load and increases the service life of the final drive parts.
Preloaded bearings are subject to high demands on the adjustment accuracy. These works must be carried out by specialists of sufficiently high qualification.
The correct adjustment of bearings is determined by the amount of torque that must be applied to the shafts mounted on bearings to rotate them.
The turning moment can be determined in the absence of special torque wrenches using a spring steelyard, which is attached to the shaft to be checked on a shoulder of a certain radius.
In the main gears, the possibility of adjusting the engagement of bevel gears is also provided.
However, it must be borne in mind that it is not advisable to regulate a working pair during operation.
It is carried out when replacing a worn pair.
Regulation of bearings and engagement of bevel gears is performed on the main gear removed from the vehicle.
The preload of the bearings is adjusted by selecting the thickness of the package of two shims located between the inner races of each pair of bearings on which the bevel gears rotate.
The tapered bearings of the differential housing are adjusted using adjusting nuts 34 (Fig. 1), which are tightened until the distance between the surfaces of the bearing caps increases by 0.1 ... 0.15 mm.
After that, the cap bolts are finally tightened, which creates the required amount of bearing preload.
The correctness of the adjustment of the bearings is checked when the car is running by the heating temperature of the bearing installation sites. Heating should not exceed 70...80°С.
Maintenance of the front axles includes monitoring the condition of the pivot joints.
To maintain the angles of inclination of the pivots of the front drive axle of off-road vehicles, the adjustment of the tapered bearings on the ball joint spikes is checked; if necessary, they are adjusted by changing the thickness of the shim package under the cover, combined with the steering knuckle lever.
The pivot joints of vehicles with a 6X4 wheel arrangement are checked with the wheels suspended so that they do not touch the floor.
The radial clearance, determined by the indicator when the wheel is rocking, should not exceed 0.25 mm, the end clearance between the eye of the axle beam and the steering knuckle should not exceed 0.25 mm.
The pivot joints must be periodically lubricated through grease fittings until fresh grease is squeezed out through the gaps between the ends of the beam eye and the steering knuckle.
In this case, to ensure the release of lubricant between the lower end of the lug and the fist, it is required to hang the wheel above the floor.
Signs of a malfunction of the drive axle mechanisms are increased noise of the final drive when the car is moving. Oil leakage may also be observed in the crankcase connectors and through the cuffs.
When the car is moving in various modes, serviceable main gears should work almost silently.
The oil temperature in the crankcase should not exceed the ambient air temperature by more than 60...70 °С.
The appearance of noise during the operation of the main gear usually indicates a violation of the engagement of the bevel gears due to wear or loosening of the bearings, as well as the appearance of an excessively large backlash between the teeth.
One of the reasons for increased driving noise is the lack of oil in the final drive housing.
Noise that occurs when cornering often indicates a malfunction in the cross-axle differential.
Faulty knocks in the final drive chipped or chipped gear teeth or damaged bearings.
In the front axle of KamAZ-4310 vehicles, this phenomenon may be associated with the destruction of parts of the front wheel drive cam cardan joint.
Continuous final drive noise when driving at high speed is usually associated with severe wear of gears, bearings, or a lack of oil in the crankcase.
You can clarify the main gear malfunction by noise using the following technique.
Accelerate the car on the highway from a speed of 20 to 80 km / h, and then reduce the speed by reducing the fuel supply.
Notice under which modes noise appears, reaches its maximum value, and disappears.
After that, accelerate the car to 80 km/h and then coast with the gearbox in neutral to a stop.
Noise noticed on the first test and not repeated on the second test indicates faults in the final drive, differential and drive axle bearings.
If, with the engine running at different frequencies, when the car is braked in place, the noises detected during the first test are heard, then we can state that these noises do not apply to axles.