Maintenance of the final drive. Main transfer service. Checking and adjusting the clutch
In the main gear, the tightening of the tapered bearings of the drive bevel gear (KamAZ-5320), bearings of the drive through shaft, tapered bearings of the intermediate shaft and the interwheel differential housing are adjusted. The bearings in these assemblies are preloaded. When making adjustments, the preload must be checked very carefully to avoid malfunctions, since too tight the bearings will overheat and fail. The main gears also provide the ability to adjust the meshing of the bevel gears. However, it must be borne in mind that it is impractical to adjust the operating pair during operation. It is carried out with a repair or a new set of a pair of bevel gears when replacing a worn pair. Adjustments of bearings and engagement of bevel gears are carried out on the main gear removed from the vehicle. Adjustment of the bearings of the drive bevel gear of the main drive of the middle drive axle of the KamAZ-5320 car is carried out by selecting the required thickness of two adjusting washers (see Fig.4.21), which are installed between the inner ring of the front bearing and the spacer sleeve. After installing the adjusting washers, the fastening nut is tightened with a torque of 240 Nm (24 kgcm). When tightening, turn the drive gear 20, so that the rollers are in the correct position in the bearing races
Then the locknut is tightened with a torque of 240-360 Nm (24-36 kgf-m) and fixed. The value of the bearing preload is checked by the torque required to turn the drive gear. When checking, the torque of resistance to turning the drive gear in the bearings should be 0.8-3.0 N-m (0.08-0.30 kgf-m). It is necessary to measure the moment of resistance with a smooth rotation of the gear in one direction and after at least five full revolutions. In this case, the bearings must be lubricated. Adjustment of the bearings of the leading bevel gear of the main gear of the rear drive axle of the KamAZ-5320 car (see Fig. 4.22) is carried out by selecting the required thickness of the adjusting washers, which are installed between the inner race of the front bearing and the support washer. The moment of resistance to turning the drive gear shaft should be 0.8-3.0 Nm (0.08-0.30 kgf-m). When checking this moment, the bearing cup cover must be moved towards the flange so that the oil seal does not resist rotation. After the final selection of adjusting washers, the nut of the universal joint flange is tightened with a torque of 240-360 Nm (24-36 kgf-m) and pinned. Tapered roller bearings (see Fig. 4.21) of the intermediate shaft of the main transmission of the KamAZ-5320 vehicle are adjusted by selecting the thickness of two adjusting washers, which are installed between the inner bearing races. The moment of resistance to turning the intermediate shaft in the bearings should be 2-4 Nm as when adjusting the bearings of the drive gear. Differential housing tapered roller bearing preload adjustment using nuts 8. Prev: the preload is controlled by the amount of crankcase deformation when tightening the adjusting nuts. When adjusting, pre-tighten the cover bolts 22 moment 100-120 Nm (10-12 kgf-cm). Then, by tightening the adjusting nuts, the bearing preload is ensured, in which the distance between the ends of the bearing caps increases by 0.1-0.15 mm. The distance is measured between the platforms for the stoppers of the differential bearing nuts. In order for the rollers in the bearing races to occupy the correct position, the differential housing must be turned several times during the adjustment process. When the required preload is reached, the adjusting nuts are locked, and the bearing cap bolts are finally tightened with a torque of 250-320 Nm (25-32 kgf-m) and also locked.
When adjusting the tapered roller bearings of the main gear and the differentials of the driving axles of the Ural 4320, the main gear with the differential and cardan flanges removed is installed in the device. All tapered roller bearings of the main drive are adjusted with preload, just like on the KamAZ-5320 car. Bearing adjustment 12, 18 (see Fig.4.24) the drive through shaft is carried out by changing the thickness of a set of shims 11 and 16. With correctly adjusted bearings, the torque of resistance to turning the drive through shaft should be 1--2 Nm (0.1--0.2 kgf-cm). The bearing cap fastening bolts must be tightened with a torque of 60-80 Nm (6-8 kgf-m). Bearing adjustment 6 the intermediate shaft is carried out by changing the thickness of the set of shims 8 under the bearing cap. By sequentially removing the gaskets, a clearance in the bearings b is selected, after which another gasket with a thickness of 0.1-0.15 mm is removed. The moment of resistance to turning the intermediate shaft should be equal to 0.4-0.8 Nm (0.04-0.08 kgf-m). Removing gaskets from under the bearing cover shifts the driven gear towards the driving gear and leads to a decrease in the lateral clearance in the engagement, therefore, it is necessary to install the removed gaskets under the bearing cup flange 5 into the set of gaskets 7 and thereby restore the position of the driven bevel gear relative to the leading one. Tighten the bearing cap bolts with a torque of 60-80 Nm (6-8 kgf-m). After adjusting the bearings of the drive through and intermediate shafts, it is advisable to check the correct engagement of the bevel gears "on the paint". The imprint on the tooth of the driven gear should be located closer to the narrow end of the tooth, but not reach the edge of the tooth by 2-5 mm. The length of the impression should not be less than 0.45 times the length of the tooth. The lateral clearance between the teeth at their widest part should be 0.1-0.4 mm. Bevel gear meshing should be adjusted by a mechanic or an experienced driver. When adjusting the bearings of the differential housing, the bearing cap mounting bolts are tightened with a torque of 150 Nm (15 kgf-m), then tightening the nuts 24, set zero clearance in bearings; after that, the nuts are turned by the size of one groove. The deformation of the bearing supports is in this case 0.05-0.12 mm. After adjustment, it is necessary to tighten the bearing cap bolts to a torque of 250 Nm (25 kgf-m).
kamaz cardan transmission
Plan:1. The purpose of the main transfer
5. Assembly of the gearbox
7. Safety precautions at T.O. and repair of the main gear
8. Literature
1.Assignment of the main transfer
The main gear is designed to transmit torque to the drive wheels at an angle of 90oC. The differential is designed to transmit torque from the main gear to the axle shafts. It allows the drive wheels to rotate at different speeds when cornering or on uneven roads.
2. Design and operation of the main gear
The front axle is a leading axle with a permanent drive from a transfer case, has a giboyed main gear and a two-satellite differential. Details of the main gear of the differential and the bearings of the front and rear axles are unified;
The main gear is flexible, the axis of the drive gear is shifted downward relative to the axis of the driven gear by 31.75 mm. The shape of the teeth of the gear wheel of the hybrid gear allows a large number of teeth to be meshed at the same time and ensures the sliding of their working surfaces, all this reduces the load on each tooth and increases the safety margin of the teeth of the main gear gears. The hybrid drive improves engagement smoothness, reduces front axle noise, and delivers more torque than a bevel helix.
In addition, the hybrid final drive reduces the height of the driveline, and therefore the floor of the body, as a result of which a more convenient placement of passengers in the body is achieved and the center of gravity of the car is partially reduced, which increases its stability.
The main gear consists of a leading and a driven gear. The pinion gear is installed in the gearbox housing on two tapered roller bearings. A spacer sleeve is installed between the inner rings between the inner rings of the bearings. A flange is put on the splined shank of the drive gear. It is attached to the shank with a self-locking nut. An oil baffle is clamped between the front bearing and the flange, which throws oil away from the oil seal. This oil seal is pressed into the throat of the crankcase and with its working edge wraps around the polished cylindrical surface of the flange. To protect the gland from dirt and damage, a dirt deflector is pressed onto the flange.
An adjusting ring is installed between the end of the drive gear and the inner ring of the rear bearing, which determines the correct position of the drive gear relative to the driven gear. This ring is available in different thicknesses from 2.55mm to 3.55mm. every 0.05mm. Seventeen sizes of the adjusting ring provide precise control of the mutual position of the final drive gears.
To prevent axial displacement of the gear under working loads, a preload is created in its bearings by tightening the nut. In this case, the spacer sleeve is deformed to a certain limit. The value of the bearing preload is controlled by a dynamometer according to the torque of the drive gear turning resistance. The moment should be equal to 16-20kgf / cm for new bearings and 4-6kg / cm for bearings after a run of 30 km or more.
The driven gear is made in the form of a crown, which is attached to the differential box flange with eight self-locking bolts. Together with the differential case, the driven gear rotates in two tapered roller bearings. These bearings are installed in the seats of the front axle gearbox housing and are closed with covers, which are bolted to the crankcase. The seat and bearing caps are threaded for adjusting nuts. These nuts adjust the lateral clearance in the meshing of the main drive gears and the preload in
differential bearings. The position of the adjusting nuts is fixed with plates that are bolted to the differential bearing caps. The tabs of the plates go into the grooves of the adjusting nuts and lock them.
Fasten the front axle to the engine brackets: on the right with a bolt through the bracket, on the left - on two studs.
The differential is conical, two-satellite. The satellites are mounted on a common axle, which is inserted into the hole in the differential box. The axle is kept from falling out of the holes by a driven gear, which overlaps the axle in the differential box. On the axle, in the places where the satellites are installed, grooves are made for better lubrication of the working surfaces of the satellites and the axle. With their teeth, the satellites are in constant mesh with the teeth of the semi-axial gears, which are mounted with their cylindrical belts in the slots of the differential box. Washers are installed between the ends of the semi-axial gears and the differential box. By selecting these washers in thickness, a gap of 0-0.1 mm is established between the teeth of the satellites and the floor of the axial gears.
Semi-axial gears have holes with splines, into which the spline ends of the hinge of equal angular velocities enter. Through these housings of the internal constant velocity joint, torque is transmitted from the differential to the drive wheels.
The front axle housing is cast from an aluminum alloy. The middle part of the crankcase is widened and has an opening, to the plane of which a stamped cover is attached. The differential and the main gear are located in the middle cavity of the crankcase. The bottom of the front axle housing is closed with a molded cover, in which the drain plug is located. The filling hole, which is also a control one, is located on the left side of the crankcase and is closed with a plug.
On the sides, the crankcase has flanges in which are bored sockets for installing bearings, housings of the internal hinges of the wheel drive. A breather is installed on the right side of the crankcase, through which the inner cavity of the crankcase communicates with the atmosphere, which prevents an increase in pressure inside the crankcase. The through hole of the breather body is closed by a valve pressed against the hole by a spring. The valve with a spring is closed with a cap. The valve prevents water from entering the crankcase when driving or stopping the car in water.
The body of the inner hinge is made together with a semi-axle, the spline end of which enters the hole of the semi-axle gear. The other end of the semi-axis of the hinge housing rests on a ball bearing. The inner ring of the bearing is sandwiched between the collar of the axle shaft and a spring washer, which is held on the axle shaft by a retaining ring. The outer ring of the bearing is secured by a locating ring, which is located in the groove in the outer ring of the bearing and is clamped between the flange of the front axle housing and the bearing cover. This retention of the bearing keeps the hinge housing from axial displacement.
An oil seal is placed in the bearing cover, protected by a reflector.
The front axle drive gear oil seal has the same dimensions as the rear axle reducer oil seal, but the notches on the protective edge of the oil seal are directed to the other, opposite side. The direction of the notch on the oil seal depends on the direction of rotation driven by the main gear, and it is shown on the oil seal by an arrow. Due to the fact that the direction of rotation of the drive gears of the front and rear axles is different, it is necessary to take into account when assembling the axles, which oil seal can be installed, since the oil seal installed from another axle will not retain oil.
3. The main malfunctions of the main gear
Constant noise when operating the front axle
1. Worn spline connection with side gears.
2. Incorrect adjustment, damage or wear of gears or bearings of the reducer.
3. Not enough oil.
Noise when accelerating a car
4. Worn or incorrectly adjusted differential bearings.
5. Incorrectly adjusted the meshing of the teeth of the gears of the main drive during the repair of the reducer.
Noise when accelerating and braking the car with the engine
6. Worn or damaged pinion bearings.
7. Incorrect side clearance between the teeth of the final drive gears.
Noise when cornering
8. Tight rotation of the satellites on the semiaxis.
9. Seizure on the working surface of the satellite axis.
10. Jamming of the axle gears in the differential box.
11. Incorrect clearance between the teeth of the differential gears.
Knock at the start of the vehicle
12. Increased clearance in the splined connection of the drive pinion shaft with the flange.
13. Increased clearance in the meshing of the final drive gears.
14. Wear of the hole for the pinion axle in the differential box.
Oil leak.
15. Worn or damaged drive pinion oil seal.
4. Methods for eliminating malfunctions of the main gear
1. Replace worn or damaged gears.
2. Determine the problem and repair the gearbox.
3. Restore the oil level and check for leaks from the seals.
4. Remove the gearbox, repair, replace parts if necessary.
5. Adjust the engagement.
6. Replace damaged parts.
7. Check the gears and replace the damaged ones, restore the normal side clearance between the gear teeth.
8. Replace damaged or worn parts.
9. Smooth off any slight roughness with a fine emery cloth. If the defect cannot be eliminated, replace the pinion axle.
10. If the gears and mating surfaces in the differential box are slightly damaged, clean them with an emery cloth, replace the damaged parts with new ones.
11.Adjust the clearance.
12.Replace final drive flange and gears.
13. Adjust the clearance.
14.Replace differential case.
15.Replace the oil seal.
5. Assembly of the reducer.
Differential assembly.
Lubricate with transmission oil and install through the windows of the differential box the side gears with support washers and satellites. Turn the planetary gears and the side gears so that the planetary gears rotate axis with the hole in the box, then insert the planetary gears.
Check the axial clearance of each half-axle gear: it should be 0-0.10 mm, and the torque of resistance to rotation of the differential gears should not exceed 1.5 kg / m.
With an increased clearance, which is a sign of wear of the differential parts, replace the support washers of the axle gears with other, thicker ones. If the specified clearance cannot be obtained even with the thickest washers, replace the gears with new ones due to their excessive wear.
Secure the driven gear to the differential case.
Press the inner rings of the roller bearings onto the differential box with a mandrel.
Installation and adjustment of the drive gear.
The correct position of the drive gear relative to the driven gear is ensured by the selection of the thickness of the adjusting ring installed between the thrust end of the drive gear and the inner ring of the rear bearing.
Select the adjusting ring using a mandrel and a tool (false shaft) with an indicator. Perform operations in the following order.
After fixing the gearbox housing to the stand, press the outer rings of the front and rear bearings of the drive gear into the crankcase sockets using mandrels.
On a false shaft that simulates a pinion gear, install the inner ring of the rear bearing with a mandrel and insert it into the gearbox.
Install the inner ring of the front bearing, the pinion flange and turning the false shaft to correct installation bearing rollers, tighten the nut to a torque of 0.8-1kg / m.
Attach the fixture to the end of the false shaft, and set the indicator, which has 0.01mm divisions, to the zero position by placing its foot on the same fixture. Then move the indicator so that its foot rests on the bearing seating surface of the differential case.
Turning left and right the false shaft with the indicator, set it to the position in which the indicator arrow marks the minimum value “a1” (the distance from the false shaft to the differential bearing journals) and write it down. Repeat this operation on the seating surface of the second bearing and read the value “a2”.
Determine the thickness “S” of the pinion adjusting ring. S = a - d, where a is the average between “a1” and “a2”, b is the deviation of the pinion gear from the nominal position given in mm. The amount of deviation is marked on the drive gear in hundredths of a millimeter with a plus or minus sign.
When determining the thickness of the adjusting ring, observe the sign of the “b” value and its unit of measurement.
Put the adjusting ring of the required thickness on the drive gear and press the inner ring of the rear bearing removed from the false shaft with a mandrel. Fit the spacer sleeve (warning: when repairing the front axle gearbox, a new spacer sleeve must be installed if the pinion bearings have been replaced). Insert the drive gear into the gear case and install the front bearing inner race, oil deflector, oil seal, drive gear flange and washer on it.
Screw a nut onto the end of the gear and, locking the flange of the drive gear, tighten it.
Drive gear bearing adjustment.
To limit the axial displacement of the drive gear under operating loads, it is very important to create a preload in its bearings within the specified limits. The preload is controlled by a dynamometer, which measures the moment of resistance to turning the drive gear.
The torque is determined by the degree of tightening of the bearings. It should be 16-20kg / cm for new bearings and 4-6kg / cm for bearings after a run of 30 km or more.
It is necessary to tighten the flange nut with a torque of 12-26 kgf / m, periodically checking the resistance torque of the bearings to the rotation of the drive gear with a dynamometer.
To check the moment of resistance, put the dynamometer on the adapter sleeve, set the torque limit indicator to the scale division corresponding to 20kgf / cm, and turn the handle counterclockwise several times. While turning the drive gear, the movable pointer should not go beyond the pointer installed on the scale, and should show at least 16kgf / cm.
If the torque of resistance to turning is less than 16 kgf / cm, and for bearings of 30 km and more - 4 kgf / cm, then tighten the nut of the drive gear flange and check again the torque of resistance to turning of the drive gear.
If the moment of resistance to turning turned out to be more than 20 kgf / cm, and for worn-in bearings 6 kgf / cm, which indicates an overestimated preload of the bearings, replace the spacer sleeve, since it was deformed from excessive load to a size that does not allow for correct adjustment. After replacing the spacer sleeve, reassemble with appropriate adjustments and checks.
Installing the differential box.
Install the pre-assembled differential case with the outer bearing races in the crankcase.
Install the two adjusting nuts so that they are in contact with the bearing rings.
Install the bearing caps and tighten the mounting bolts with a torque wrench with a load of 5.5 kg / m.
Preloading the differential box bearings and adjusting the side play in the meshing of the final drive gears.
These operations are performed simultaneously using a tool and a key.
Fasten the device (Fig. 1) to the gearbox housing with screws 1 and 6, screwing them into the holes for the bolts securing the lock plates of the adjusting nuts.
Along the guide of the device, move the bracket 7 until the lever 5 touches the outer side surface of the cover and tighten the screw 8.
Loosen screws 1 and 3 (Fig. 2) and install bracket 4 so that the indicator foot 2 rests on the lateral surface of the driven gear tooth at the tooth, then tighten screws 1 and 3.
Turning the adjusting nuts, pre-adjust the side clearance between the teeth of the driving and driven gears within 0.08-0.13mm. The clearance is checked by indicator 2 when the gearwheel 6 is wiggling, while the bearings should not have a preload. The adjusting nuts must only be in contact with the bearings, otherwise the correct preload measurement will be impaired.
Tighten the two bearing adjusting nuts consistently and evenly, while the differential bearing caps diverge and, therefore, the distance “D” increases - which is measured by indicator 9 (Fig. 1), on the leg of which lever 5. The nuts for adjusting the differential box bearings are tightened to increasing the distance “D” by 0.14-0.18mm.
Having established the exact preload of the differential box bearings, finally check the side play in the meshing of the main gears, which should not change.
If the clearance in the meshing of the gears is more than 0.08-0.13 mm, then bring the driven gear closer to the driving gear or move it back if the clearance is less. To maintain the set bearing preload, move the driven gear by tightening one of the bearing adjusting nuts and loosening the other by the same angle.
For accurate performance of this operation, watch the indicator 9 (Fig. 1), which shows the value of the previously set bearing preload. After tightening one of the nuts, the indicator reading will change, as the divergence "D" of the caps and the preload of the bearings increase. Therefore, loosen the nut until the indicator arrow returns to its original position.
After moving the driven gear on indicator 2 (Fig. 2), check the value of the side clearance. If the clearance is not correct, repeat the adjustment.
Remove the fixture, install the adjusting nut lock plates and secure them with bolts and lock washers. Spare parts are supplied with locking plates of two types: with one or two lugs, depending on the position of the slot of the nut.
Adjustment and repair of gearbox assemblies is performed on a stand, where you can also test the gearbox for noise and check the location and shape of the contact patch on the working surfaces of the teeth.
6. Maintenance of the final drive
When T.O.-1 check the fastening of the bridge. The sopun is also cleaned and the oil level is checked, if necessary, top up to the filler cap.
When T.O. - 2 also check the oil level. Inspect the condition of the main gear and satellites.
Under S.O. carry out an oil change in the gearbox, while it is washed. Check the breather if necessary.
7. Safety precautions for T.O. and repair of the main gear
Safety precautions must be observed when servicing the gear unit. Work only with serviceable tools, in a ventilated area, in special clothing. If oil is spilled on the floor, remove it with sawdust or sand. Do not smoke near the place of repair work, as well as do not use a welding machine or other equipment in the vicinity that may cause ignition of oil. The used oil is drained into special vessels, after which it is handed over to recycling... After finishing work, put the tools on their workplace storage.
Literature.
1. Ignatov A. P., Novokshonov K. V., Pyatkov K. B. "VAZ 21213-21214i - device and operation" 1996. pp. 36-37
2. Ershov B. V., Yurchenko M. A. “ Cars VAZ, construction and maintenance ”1983. pp. 140-141
3. Autolada - Togliatti "VAZ, repair manual" 1989. pp. 69-76
4. Lecture notes PU-16, in the following subjects: "The device of the car", "T.O. car ”1999-2002.
- broken teeth, wear or improper adjustment of the gearing of the main gears;
- wear of bearings and their seats, as well as increased axial clearance;
- wear of the necks of the cross and the end surfaces of the satellites and semi-axial gears;
- wear of the splines and keyway of the axle shafts;
- development of oil seals and wear of their landing sites.
- unscrew the lock plates of the adjusting nuts 2 and b and unscrew the nuts;
Disassembly of the main gear and differential
Rice. The main gear and differential of the GAZ-51 car:
1 - drive gear flange; 2 - drive gear shaft; 3 - stuffing box; 4 - bearing seat; 5 - tapered roller bearings; 6 - rear axle housing; 7 - roller bearing; 8 - satellite; 9 - breather; 10 - stuffing box; 11 - semiaxis; 12 - axle shaft casing; 13 - brake pipeline; 14 - differential cup; 15 - drain plug; 16 - gasket; 17 - driven gear; 18 - differential cup; 19 - semi-axle gear; 20 - differential bearing; 21 - oil deflector; 22 - supporting bronze washer of the semi-axle gear; 23 - differential crosspiece; 24 - satellite support washer; 25 - base plate; 26 - gaskets for adjusting the bearings of the drive gear; 27 - gaskets for adjusting the engagement of the main gears; 28 - bearing cover; 29 - dirt reflector; 30 - flange nut.
To disassemble the single main gear of the GAZ-51 car, you must:
- unscrew the nuts of the studs securing the flanges of the axle shafts and remove the axle shafts 11;
- unscrew the bolts securing the two halves of the crankcase, disconnect them and remove the differential assembly;
- unscrew the bolts securing the cover 28 and the seat 4 of the bearings of the main gear drive gear and remove the drive gear together with the flange 1 and the seat with bearings 5 from the crankcase;
- unpin and unscrew the nut 30 for fastening the flange, remove the flange, the oil seal 3, the bearing cover 28, the thrust ring, the bearing seat and the shims 27;
- remove the tapered roller bearing from the drive gear shaft 2, remove the circlip and the cylindrical roller bearing 7 from the drive gear end;
- unpin and unscrew the bolts connecting the two halves of the differential cup 14, disconnect the cup, remove the crosspiece with the support washers 24 of the planetary gears 8 and the half-axle gears 19 also with the support bronze washers 22.
Rice. The main gear and differential of the ZIS-150 car:
1 - semi-axis; 2 and 6 - differential bearing adjustment nuts; 3 - bearing cover; 4 - differential cup; 5 - driven cylindrical gear; 7 - intermediate shaft bearing caps; 8 - gaskets of bearings of the intermediate shaft and meshing of bevel gears; 9 - gaskets for adjusting the engagement of bevel gears; 10 - a glass of the driving gear; 11 - spacer sleeve; 12 - bearing cover gaskets; 13 - bearing cover; 14 - flange; 15-seals; 16 - drive gear bearing adjusting washers; 17 - intermediate shaft.
To disassemble the double main gear of the ZIS-150 car, you must:
- unscrew the flange bolts of the axle shafts and take out the axle shafts 1;
- unscrew the rear crankcase cover;
- unscrew the lock plates of the adjusting nuts 2 and 6 and unscrew the nuts;
- unpinning and unscrewing the nuts, remove the bearing caps 3 of the differential cup 4 and remove the differential assembly;
- unscrew the glass 10 and remove it assembled with the drive gear;
- Disconnect the final drive housing, unscrew the bearing caps 7 of the intermediate shaft 17 and remove it from the crankcase.
Differential cup repair
Differential cup defects are:
- wear of bearing seats;
- wear of the holes for the necks of the satellite cross-pieces;
- wear of holes for semiaxis gear journals.
The worn out seats of the bearings of the differential cup are restored by chromium plating, followed by grinding to the required size, as well as by metal deposition by welding. Surfacing should be carried out with heating to avoid cup warping. If the differential cup is made of steel, then cold expansion of the bearing seats can also be used.
To do this, a conical mandrel, abundantly greased with oil, is driven through the hole of the cup under a press. After distribution, the necks are grinded on a lathe. When the holes intended for the spider necks are worn out, these holes are deployed under the increased size of the necks, which are pre-chrome plated to obtain a tight fit when the differential cup is assembled. Worn holes for the journals of the semi-axle gears are bored on the machine, and to obtain a normal fit of the journals of the semi-axial gears, the surface of the journals is chrome plated. The holes are also repaired by boring the holes and then pressing in bushings of a material suitable for the cup material. After pressing in, the bushings are processed to the size of the necks of the semi-axial gears with the expectation of obtaining the required clearance.
Repair of the crosspiece of satellites
During operation, the necks of the satellite crosspieces wear out strongly in the landing sites.
To restore the seats of the satellites, the holes of the latter are grinded or deployed until the correct geometric shape is obtained, and the necks of the crosspiece are increased with chrome plating and the size of the holes of the satellites is ground with iodine.
If it is impossible to apply chrome plating, the necks of the crosses are ground or grinded with a cutter (after annealing the necks), and then cemented steel bushings are pressed onto them and grind them to the size of the holes of the satellites. A more complicated method of restoring the necks of the crosspiece is surfacing of metal on them by welding, followed by machining and carburizing.
Repair of gears, shafts and axle shafts
Worn and chipped gear teeth are repaired in the ways indicated. Worn end surfaces of half-axle gears and satellites are grinded or grinded with the subsequent installation of new washers that take axial load. In this case, the gap between the ground face of the side gears and the inner surface of the cup should be 0.5-0.8 mm.
The gap is checked with a feeler gauge through the windows of the differential cup. The difference in the gaps when measuring in all windows should not exceed 0.1 mm.
Worn bearing seats on the drive gear shaft and on the intermediate shaft of the main gear are restored with chrome plating or grinding, followed by pressing steel bushings. The crumpled splines of the semi-axles and the drive gear shaft (in the absence of twisting) are repaired by fusing the metal with welding, then the splines are milled and thermally treated.
When the thread is stripped at the end of the drive gear shaft or at the end of the semiaxis (GAZ-MM and M-20 "Pobeda" cars), the thread is cut by grinding on the machine, then the metal is welded, machined to the required size and a new thread of the nominal size is cut.
Assembly and adjustment of the final drive and differential
The assembly of a single main gear and a differential (GAZ-51 car) is performed in the following order:
- The outer rings of the bearings of the main drive pinion are pressed into the bearing seat with an interference fit of up to 0.08 mm.
- One tapered roller bearing is pressed onto the shaft journal close to the drive gear, put on a spacer sleeve, shims 26, a bearing seat, another tapered roller bearing, a thrust ring, a cardan joint flange 1 and tighten the shaft flange nut 30 to failure. When tightening the nuts, turn the drive gear by the flange, which ensures the correct position of the rollers in their rings. After tightening the nut, check the torque with a dynamometer, which should be in the range of 14-18.5 kgm. In the absence of a dynamometer, the tightening of the bearings is checked by turning the gear by the flange. In this case, the gear should turn from a slight hand force and have an axial clearance (roll) of no more than 0.04 mm, which is checked by an indicator. If the axial clearance is greater, then remove one or two shims, if the tightening is too tight, then add shims. After the final tightening of the bearings, risks are applied to the nut and shaft end.
- Unscrew the nut, remove the flange, put on the bearing cap 28 with the gland 3 and install the flange; then tighten the nut until the marks are aligned and cotter pin.
- A cylindrical roller bearing 7 is pressed onto the end of the drive gear and a retaining ring is installed.
- Tapered roller bearings 20 are pressed onto the journals of the differential cup.
- A support bronze washer, a half-axle gear, a cross assembly with support washers and satellites, a second half-axle gear with a support washer and the right half of the differential cup are installed in the left half of the differential cup so that the existing marks on both halves coincide.
- Bolt both halves of the cup with bolts and cotter the bolts with a common wire.
- Install as many shims 27 as they were removed during disassembly from the bearing seat of the drive gear, insert the drive gear into the rear axle housing and tighten the bolts.
- Install oil baffles 21 and oil seals 10 in the axle shaft casings from the side of the main gear housing and press the outer rings of the bearings 20 of the differential cup.
- The differential cup 14 is installed in the crankcase assembly; a gasket 16 with a thickness of 0.20-0.25 mm is placed in the crankcase connector (after tightening the bolts, the thickness of the gasket should be 0.15 mm, which ensures a normal clearance in the gear engagement), and the crankcase bolts are tightened.
- Check the clearance in the meshing of the gears, which must correspond to the angular displacement of the drive gear flange by 0.3-0.9 mm, when measuring the displacement by the indicator on the diameter of the flange holes. The size of this gap is adjusted by changing the thickness of the spacers 27 between the crankcase and the bearing seat of the drive gear. To remove or add gaskets, unscrew the drive pinion shaft nut, remove the flange, the cover with the oil seal, the thrust ring and the bearing seat. After changing the number of shims, reassemble and check the gap.
- Insert axle shafts 11 and tighten the nuts for fastening their flanges.
Removing the main transfer
Drain the oil from the axle beam.
Lift the rear of the car, place it on the stands and remove the wheels.
Unscrew the nuts securing the brake shield to the beam and extend the axle shafts so that they come out of the differential box.
Disconnect the propeller shaft from the gearbox, place a stand under the gearbox housing, unscrew the bolts of its fastening to the rear axle beam and remove the gearbox from the beam without damaging the gasket.
Dismantling the main gear
Fix the gearbox to the stand. Remove the lock plates, remove the bolts and remove the differential case bearing caps, adjusting nuts and roller bearing outer races. Before removing, mark the caps and outer rings of bearings so that they can be installed in their original places during assembly. Remove the differential box together with the driven gear and inner bearing rings from the gearbox housing.
Figure 2- Stand for disassembling the final drive
Turn the gearbox housing with the neck up and, holding the flange 3 of the drive gear with a stopper 1, unscrew the flange fastening nut with a wrench 2 (4 - the bracket for mounting the gearbox on the stand). Remove the flange and take out the pinion gear with the shim, the inner ring of the rear bearing and the spacer sleeve. Remove the oil seal, oil deflector and front bearing inner ring from the gearbox housing. 6. You press the outer rings of the front and rear bearings with a mandrel A.70198. Remove the spacer sleeve from the drive gear and using a universal puller A. bearing. Remove the drive gear adjusting ring.
Dismantling the differential
Remove the inner rings of the differential box roller bearings using the universal puller А.40005 / 1/6 and the stop А.45028. Unscrew the nuts securing the driven gear and knock the pinion axle out of the box. 11. Rotate the axle gears and satellites so that the latter roll out into the differential windows, after which they can be removed. 12. Remove the axle shaft gears with support washers.