LUBRICATION OF THE YAMZ-239 GEARBOX
Gearbox lubrication is mixed - pressure and spray lubrication.
The bearings of the pinion shaft gears, the bearings of the demultiplier satellites, the front bearing of the secondary shaft, gears are lubricated under pressure planetary gear range, front bearing shaft range.
The spraying lubricates the gearing of the gears of the main gearbox, the bearings of the input shaft and the rear secondary shaft, the rear bearing of the demultiplier shaft, the parts of the synchronizers, the parts of the gear shifting mechanism.
Countershaft gears and bearings, idler gear reverse partially immersed in oil, poured into the cavity of the gearbox crankcase through a threaded hole in the spacer between the crankcases of the main gearbox and the range multiplier. The oil level is determined by the lower edge of this hole, while refueling capacity will range from 9.5 liters (horizontal) to 11.5 liters (when tilted back 7 degrees), depending on the angle of the gearbox axis, which depends on the angle of the axis crankshaft engine. When the intermediate shaft rotates, the teeth of its gears capture oil, which enters the gearing, and also splashes in the form of a large number of drops, falls on other parts and in the gaps between the parts. The amount of oil suspended in the crankcase cavity in the form of fine droplets (oil mist) depends on the intermediate shaft speed, oil temperature and its viscosity characteristics.
The lubricant is supplied under pressure by a gear pump, the appearance of which is shown in Figure 28, installed on the front end of the gear case (see Figure 2).
Rotation of the pump drive gear is ensured by connecting the pump shaft to intermediate shaft by means of a groove formed by the flat ends of 2 rollers installed in the radial holes of the intermediate shaft (see Figure 5) and two flat flats on the pump shaft. The pump design is shown in Figure 29.
Oil is taken by the pump from the crankcase through the intake mesh and then along the longitudinal and vertical channels (drilled holes) in the walls of the crankcase enters the suction cavity to the gears of the oil pump. The gears of the pump capture oil and feed it under pressure through the oil line (tube) into the cavity of the bearing cover of the primary shaft, from which oil from the groove through three inclined holes in the primary shaft and the oil bypass pipe (see Figure 3) enters the central hole of the secondary shaft (see Figure 8). The cover with a movable input shaft of the gearbox is sealed with a lip, the direct supply of oil to which is prevented due to the minimum clearance of the bore of the cover with a sealing ring on the input shaft. Oil leaked through the gap without pressure through the drain channel in the cover is used to lubricate the input shaft bearing.
The scheme of oil supply to the main gearbox of the YaMZ-239 type and to the demultiplier is shown in Figure 30. From the central hole of the secondary shaft, oil flows through the radial holes to the roller bearings of the secondary shaft gears. From the end of the central hole of the secondary shaft, the oil through the oil bypass pipe 4 (see Figure 30) enters the central hole of the demultiplier shaft extension and then through the radial holes 8 of the demultiplier shaft extension and the inclined hole 7 of the demultiplier shaft enters the oil accumulator cavity 13 formed by the surfaces output shaft, high range gear clutch, oil accumulator rings. From the named cavity, the oil flows through the inclined holes 6 of the axes of the satellites to the roller bearings and then, through the gaps between the end surfaces of the satellites and the surfaces of the shaft, the output oil enters the teeth of the ring gear.
The front bearing of the output range shaft is lubricated with oil coming through the radial hole 10 of the oil bypass pipe 4. The front bearing of the output shaft is lubricated through the radial hole 14 of the primary shaft tube 3.
The teeth of the sun gear, satellites, ring gear and the rear bearing of the output shaft are additionally lubricated with oil coming from the central hole of the output shaft extension and then through the radial hole 5 in the extension, the inner cavity of the sun gear, clearances in the tooth connection of the coupling with the sun gear. Oil is also added here after lubrication. front bearing the shaft of the output range.
Oil trapped on the sun gear teeth is transferred to the planet gear teeth and to the ring gear teeth. Oil passing through the gaps in the gear coupling towards the output shaft lubricates the output shaft rear roller bearing.
For additional lubrication of the front bearing of the intermediate shaft, channel D is made in the oil pump housing (see Figure 29). Grease rear bearing the intermediate shaft is carried out in the same way with oil drained from the range multiplier into the crankcase of the main gearbox.
Lubrication of the rear bearing of the output shaft of the demultiplier and the worm gear of the speedometer drive is provided with oil mist, as well as the rest of the gearbox parts of the YaMZ-239 type.
Drainage of oil from the main gearbox crankcase and demultiplier crankcase is provided through a threaded hole in the lower part of the main gearbox crankcase, which is closed with a special plug with magnets to collect magnetic metal particles - wear products of gearbox parts.
4.2. Transmission
Clutch release drive
The clutch release drive (Figure 15) is hydraulic with a pneumatic booster.
The operation provides for the adjustment of the full and free travel of the clutch pedal. The adjustment of the total travel, which should be 125 mm, is carried out before adjusting the free play with stop bolts 4 and 8 with the lock nuts released. After completing the adjustment, lock the stop bolts with nuts.
To eliminate fluid pressure in the hydraulic system of the clutch drive when the clutch is not disengaged, it is necessary to adjust free run clutch pedal, changing the length of the rod 4 (Figure 16), rotating the pusher 2 with the nut 3 released so that the free travel of the pedal 1 until the stop of the rod 4 against the piston of the master cylinder 5 is 5 - 7 mm.
Filling the clutch actuator working fluid and its pumping is carried out in the absence of air in the pneumatic system of the car in next order:
Check the amount of free and full travel of the clutch pedal and, if necessary, adjust;
Remove the protective cap from the valve 6 (Figure 15) and put a hose on the valve head, the free end of which is lowered into the vessel with the working fluid. Then unscrew the bypass valve 6 by one turn and fill the tank 5 of the master cylinder 2 with liquid;
Watching the liquid level in the tank, smoothly press the clutch pedal to pump the hydraulic drive of the booster until the bubbles disappear completely air in the vessel;
After bleeding, screw on the bypass valve, remove the hose and put on the cap;
Bring the liquid level in the reservoir to a mark 15 mm below the filler neck.
It is allowed to fill the system with liquid through the passage valve PGU6 under a pressure of 2-3 kgf / cm2. In this case, the liquid should go into the tank 5. Pumping is carried out until the air bubbles in the liquid leaving the tank 5 completely disappear.
After filling the system with fluid, it is necessary to check the efficiency of the clutch actuator. To do this, if there is air pressure in the pneumatic system of the car, it is necessary to press the clutch pedal all the way and check the ease of engaging the gears in the gearbox. At normal work the clutch and its drive when the engine is running, the gears in the gearbox must be engaged without jamming and noise.
For cars equipped with a gearbox with a splitter, when the clutch pedal is depressed to the stop, bracket 7 (Figure 16) must move the valve stem of the gearbox splitter installed on the front panel of the cab by (3 + 0.5) mm. In this case, the air must flow to the gearbox divider. The adjustment is carried out in the presence of air in the pneumatic system of the car by moving the bracket 7 with the bolts 8 released.
Figure 16. Brake clutch control unit
1 - pedal; 2 - pusher; 3 - nut; 4 - stock; 5 - hydraulic cylinder; 6 - bolt, 7 - bracket; 8 - bolt
Gearbox MAZ - 543205
A warning
1.The use of oils that are contaminated or not specified in this manual is not allowed.
2.It is not allowed to engage the transmission in the main box until the selected range of the range is turned on, that is, until it lights up control lamp when the slow range is on, or until it turns off when the fast range is on. Demultiplier switching time 0.5 - 1.0 sec.
3.When the car is moving, it is strictly forbidden to engage the first gear in the main gearbox when the fast range of the range is engaged.
4. Engage the first gear and reverse gear only after the vehicle has come to a complete stop and with the slow range engaged in the range.
5. It is not allowed to include the slow range of the range multiplier when the vehicle speed is higher than the minimum speed specified in table 1.
6.It is not allowed to change gears during car movement when the power take-off is on.
7.It is not allowed to increase the number of engine revolutions, when braking the car with the engine, over maximum speed idle move.
8. The maximum temperature of the oil in the gearbox is 120 ° C. Short-term operation (no more than 2 hours) is allowed at oil temperatures up to 145 ° С.
Preparing the transmission for operation
Before operation, it is necessary to check the connection of the transmission control systems to the corresponding vehicle systems:
Pneumatic control system for the demultiplier to the pneumatic valve of the gearshift mechanism located in the gearshift lever, and the reducing valve to the pneumatic system of the vehicle;
Power supply of the automatic blocking system of the electronic-pneumatic type (АСБП) to the car wiring diagram;
Power supply of the control lamp for switching on a slow gear in the range multiplier and for switching on the reverse gear to the vehicle's electrical system;
The lever of the shaft of gear shifting to the drive of the transmission control.
Check the oil level in the gearbox by unscrewing the plug with the level indicator from the filler hole located on the right side of the gearbox housing, and then insert the plug with the indicator into the hole until it stops in the thread. The oil level should be at the top mark on the gauge. After checking the oil level, screw the plug into the hole.
Check the operation of the ASBP, for which first make sure that when the slow gear is engaged in the demultiplier, the control lamp is on, and when switching to fast transfer- goes out. Shift gears in the range switch with the range switch located on the gear lever knob, when the air pressure in the pneumatic system of the car is not less than 450 - 490 kPa (4.5 - 4.9 kgf / cm 2).
Table 1
|
Drive axle gear ratio |
Tires |
Vehicle speed, km / h |
|
|
minimal |
maximum |
||
|
7,14 |
|||
|
6,59 |
|||
|
5,49 |
|||
|
4,84 |
|||
|
3,97 |
|||
|
6,94 |
11.00R20, G k = 0.525 m |
||
|
5,33 |
|||
|
4,59 |
|||
|
3,86 |
|||
|
3,57 |
|||
|
6,59 |
|||
|
5,49 |
|||
|
4,84 |
|||
|
3,97 |
|||
|
315 / 80R22.5, G k = 0.523 m |
|||
|
5,33 |
|||
|
4,59 |
|||
|
3,86 |
|||
|
3,57 |
|||
|
7,79 |
|||
|
7,14 |
|||
|
6,59 |
|||
|
5,49 |
|||
|
4,84 |
|||
|
3,97 |
|||
|
7,57 |
12.00R20, G k = 0.547 m |
||
|
6,94 |
|||
|
5,33 |
|||
|
4,59 |
|||
|
3,86 |
|||
|
3,57 |
|||
Accelerate the vehicle to a speed 5-10 km / h higher maximum speed specified in table 1. The maximum speed according to the table is determined for each car, depending on gear ratio rear axle and tires fitted to the model vehicle. Squeeze the clutch, disengage the gear in the main gearbox, engage a slow gear in the range multiplier and observe the warning lamp and the vehicle speed. The UPS is defective. In this case, it is necessary, without releasing the clutch pedal, to reduce the speed by 5 km / h below the minimum specified in Table 1, and then switch. If the inclusion of a slow gear in the range multiplier occurs when the vehicle speed is below the minimum specified in Table 1, the ASBP is working properly.
Check the operation of the pneumatic blocking of the 1st gear and reverse gear in the main gearbox in the following sequence:
Set the gear shift lever to neutral;
Switch on a slow gear in the range and make sure that the force on the head of the gear shift lever when moving it towards the engagement of the first gear and reverse gear is 5 - 10 kg;
Switch on fast gear in the range and check the force on the head of the gear shift lever when moving it towards engaging the first gear and reverse; the effort should be 4 - 5 times greater than the inclusion in a slow gear in the demultiplier.
Maintenance
Maintenance work is mandatory and must be carried out strictly on time.
Maintenance of the gearbox by frequency and work performed is divided into the following types:
Daily maintenance (EO);
Maintenance after running-in the car (2000 km of run);
First maintenance (TO - 1);
Second maintenance (TO - 2).
Gearbox maintenance intervals ( TO - 1 and TO - 2) corresponds to the frequency of maintenance of the vehicle on which it is installed.
During maintenance, it is necessary to ensure conditions that exclude the ingress of dust and dirt into the gearbox assemblies.
Daily maintenance
Check by visual inspection for oil leaks from the gearbox. Check the tightness of the pneumatic range control system. Air leaks are audible. Alternately moving the range switch to the up and down positions, listen to the air ducts whenneutral position of the lever in the main box and with any gear engaged. If oil or air leaks are found, identify the cause and correct the malfunction.
Maintenance after vehicle break-in
After running in the car, drain the oil from the gearbox housing, clean the magnet drain plug from metal particles, the cover installed on the bottom of the lower crankcase, clean from wear debris. Drain the oil from the box immediately after hot work. After draining the oil, flush the crankcase with liquid industrial oil, for example, I-12A or I-20A in accordance with GOST 20799 - 88. Do not flush the gearbox diesel fuel or kerosene. Fill in fresh oil up to the upper mark on the dipstick.
First maintenance (TO - 1)
Check oil level and top up if necessary.
Maintenance after one MOT - 2
Change the oil in the gearbox following the steps Maintenance after running in the car.
Clean and lubricate with Litol - 24 GOST 21150 - 87 spool, piston, inner surfaces of the air distributor cylinders, piston cuffs and inner surfaces of the range switch cylinder.
Check the operation of the automatic control system according to the method described in the section "Preparing the transmission for operation". Check the air pressure at the outlet of the pressure reducing valve, which should be within 450 - 500 kPa (4.5 - 5 kgf / cm 2). Check the tightness of the pneumatic range control system. The detected air leaks can be eliminated by tightening the bolts or by replacing the sealing washers.
Transmission oils approved for use in the gearbox and recommended viscosity grades transmission oils depending on the ambient temperature, ° С, are given in table 2.
table 2
|
Oil grade |
Standard number |
Manufacturer |
|
TSp-15k (SAE85W-90) |
GOST 23652-79 |
JSC "Omsk Oil Refinery" |
|
TAD-17H (SAE85W-90, GL-5) |
GOST 23652-79 |
JSC "Plant im. Shaumyan ". JSC "Lukoil-Volgograd-oil refining" |
|
Angrol TSp-15k (SAE85W-90) |
GOST 23652-79 |
Angarsk Oil Company JSC |
|
YarMarka Hypoid TM 5-18 (SAE85W-90, GL-5) |
TU 0253-021-00219158-96 |
OJSC "Yaroslav nefteorgsintez" and JV "Yar.Marka" |
|
Fair Super ETM 5-18 (SAE85W-90, GL-5) |
TU 0253-018-00219158-96 |
|
|
"YarMarka T" TMZ-18 (SAE80W-90, GL-3) |
TU 0253-019-00219158-96 |
OJSC "Yaroslavnefteorgsintez" and JV "Yar.Marka" |
|
"Omskoil K" TM 3-18 (SAE80W-90, GL-3) |
TU 38.301-19-95 |
JSC "Omsk Oil Refinery" |
Note:
1. At an ambient temperature below minus 20 ° C, it is allowed to use a mixture of transmission oil (85%) approved for use with diesel fuel of grade "A" or "3" (15%)
2.Oil MT-16P GOST 6360-83 is allowed for use in a gearbox with a halved replacement period
3.It is allowed to use imported gear oils with a performance level according to API of at least GL-4, viscosity class according to table 2
Possible gearbox malfunctions and how to fix them
|
Cause of malfunction |
Remedy |
|
Difficulty shifting gears and the main gearbox. The first gear and reverse gear are engaged with a grinding noise. |
|
|
Incomplete clutch release (clutch "leads") |
Adjust clutch pedal free play or replace damaged parts |
|
The inclusion of the second, third, fourth, fifth gears is difficult, their inclusion occurs with a grinding sound |
|
|
Worn cone rings of synchronizers Replace the synchronizer |
|
|
Gears are not included in the main gearbox |
|
|
Wear of the gear rims of the synchronizer carriage, toothed couplings, installed on the gears of the 2nd, 3rd, 4th and 5th gears, the gears of the first gear and reverse gears or the gear rims of the gears of the first gear and reverse gear |
Replace defective parts |
|
Worn parts or misadjustment of the remote gearshift drive |
Replace defective parts; adjust the remote gearshift drive |
|
The inclusion of gears in the range multiplier occurs with a bang and grinding |
|
|
High blood pressure in the pneumatic control system of the demultiplier |
Adjust pressure reducing valve |
|
Worn cone rings in the synchronizer. Wear of the locking chamfers of the fingers and the synchronizer carriage |
Replace synchronizer |
|
Non-disengagement or delayed engagement of gears in the range multiplier when |
|
|
Rubber wear intake valve |
Replace valve |
|
Worn valve stem O-ring |
|
|
Uneven adherence of the intake valve to the shoulder of the body |
Replace defective parts |
|
Inlet valve stuck in depressed position |
Rinse, blow out, and lubricate the valve stems and cap opening. Polish the rod if necessary |
|
Intake valve body o-ring hardened |
Replace the O-ring |
|
Worn or hardened piston rod seal rings of the power cylinder |
Replace O-rings |
|
Air exits through the gearbox breather when the slow gear is engaged in the range |
|
|
Worn or hardened air distributor piston O-ring |
Replace the O-ring |
|
Worn or hardened sealing rings of the air distributor valve |
Replace O-rings |
Possible gearbox malfunctions and ways to eliminate them (end)
|
Cause of malfunction |
Remedy |
|
Low pressure in the pneumatic system of the gearbox |
|
|
Worn or hardened power cylinder piston cuff |
Replace the cuff |
|
Rupture of the diaphragm of the inlet valve of the air distributor |
Replace the diaphragm |
|
Air exits through the gearbox breather |
|
|
Rupture of the diaphragm of the locking device of the first gear and reverse |
Replace the diaphragm |
|
Air exits through the gearbox breather when fast gear is engaged in the range |
|
|
Self-switching off of gears on the move of the car |
|
|
Incomplete engagement of the gear due to wear of the forks crackers, due to misalignment of the remote drive at the board |
Tighten fasteners, replace worn parts, adjust control drive |
|
Wear of gear couplings of gear wheels and synchronizer carriages due to incomplete engagement |
Replace worn parts |
|
Increased noise during the operation of the gearbox |
|
|
Loosening of the bolts securing the clutch housing to the flywheel housing |
Tighten the bolts |
|
Gear teeth wear |
Replace gears |
|
Shaft or pinion bearings worn |
Replace gears |
|
Not enough oil and gearboxes |
Add oil to the upper mark on the oil level indicator |
|
Oil leaks from the gearbox |
|
|
Wear or loss of elastic cuffs |
Replace cuffs |
|
Increased crankcase pressure |
Flush breather |
|
Leakage violation on sealing surfaces |
Tighten fasteners |
|
Enabling slow range at vehicle speeds |
|
|
Opening of electrical circuit contacts |
Restore contact |
|
Breakage of 15 wires of the ASBP system |
Replace wire |
|
Defective relay blocking ASBP |
Replace relay 6312.3 747 |
|
Defective speed sensor |
Replace speed sensor 1101.3843 |
|
Blocking valve defective |
Replace defective parts |
Gearbox control drive
The gearbox drive MAZ - 543205 and YaMZ - 239 is shown in Figure 17. During operation, if necessary, the following gearbox drive adjustments are made:
The adjustment procedure is as follows:
Set lever 2 to neutral position;
By longitudinal movement of the plate 16 with the bolts 17 released, set the angle a of the lever 1;
By changing the length of the rod 3, set the angle?.
In case of insufficient plate travel 16 or thrust adjustment range 3, loosen the bolts 5, move or rotate the rod 6 relative to the shank 4, tighten the bolts 5 and repeat the adjustment of the angles a, b, as stated above.
Injection a must be 80 °, angle v - 90 °.
Adjust the locking device of telescopic elements with the cabin raised as follows:
Undo the pin 8 and disconnect the rod 6 from the fork 9 of the gearbox drive lever;
Push the inner rod 6 up to the stop of the projections of the earring 12 into the grooves of the tip 15;
Keeping the mechanism compressed, screw in the shank until the mechanism is locked by the sleeve K) under the influence of the spring 11:
minimal. In the unlocked position, the sleeve 10 is shifted to the left.
The movement of the extension should be smooth, without jamming, and the locking mechanism should ensure that the extension rod is firmly locked in its original position.
When connecting rod 6 to fork 9, the hole in the shackle for pin 8 should be located above the longitudinal axis of rod 6.
Adjust the drive with the engine off.
When the cab is lifted, oil under pressure from the cab lifting pump is supplied through the hose 7 to the cylinder of the locking device and the mechanism 6 is unlocked.
After lowering the cab, to securely fix the telescopic mechanism 6 in the locked position, it is necessary to move the gear shift lever 1 forward in the direction of the vehicle in a movement similar to engaging a gear. In this case, the mechanism is blocked and is subsequently ready for operation.
Gear shift diagram of KP MAZ - 543205 and YaMZ - 239, see Figure 18.
Figure 17.Transmission control drive
1 - lever arm; 2 - lever; 3.4 - thrust; 5.17 - bolt; 6 - thrust (telescopic mechanism); 7 - hose; 8 - finger; 9 - plug; 10 - bushing; 11 - spring; 12 - earring; 13 - lock nut; 14 - shank; 15 - tip; 16 - plate; 18 - switch
Gearbox control drive with MAN engine
When operating the gearbox, observe the following:
1.The main gearbox and the demultiplier are controlled using the gearbox lever according to the diagram shown in Figure 19 (gearbox ZF).
2. The transition of the slow range of the range to the fast one is carried out by moving the lever in the neutral position in the direction away from you, overcoming the force of the retainer, from the fast range to the slow one - in the reverse order.
3.The divider is controlled by a flag on the handle of the gearbox lever. The transition from the slow range (L) to the fast (S) and vice versa is carried out by pressing the clutch pedal all the way after the flag is moved to the appropriate position. Shifting is possible without disabling the transmission in the main gearbox.
Adjustment of the transmission control drive
During operation, if necessary, the following gearbox drive adjustments are made:
Adjusting the position of the lever in the longitudinal direction;
Adjusting the position of the lever in the transverse direction;
Adjustment of the locking device of the telescopic drive elements.
Adjustment of the position of the lever 1 (Figure 20) in the longitudinal and transverse directions is carried out by moving and rotating the rod 5 in the shank 6 with the bolts 7 released.
In this case, the angle a should be 85 °, angle e = 90 °. The angle a can also be adjusted by moving the plate 3 with the bolts 2 released.
Adjustment of the locking device of telescopic elements is similar to the KP MAZ - 543205 (see above). The drive is adjusted when the engine is not running.
Figure 18. Scheme of gear shifting KP MAZ - 543205, YaMZ - 239
M - slow range; B - fast range
Figure 19. Scheme of gear shifting of the ZF gearbox
L - slow range; S - fast range
Drawing20. transmission control drive
1 - lever; 2, 7 - bolt; 3 - plate; 4 - hose; 5 - intermediate mechanism; 6 - shank; 8 - growl
The gearbox drive of MAZ cars - 544004, 544003, 534004, 534003 is shown in Figure 21.
Switching of the main box is made by lever 1 of the mechanism remote control... The additional box is controlled by the range switch 18 located on the gear shift lever 1.
The lower position of the range switch turns on the fast range in the additional box, with the upper position the slow range.
During operation, if necessary, the following are produced:
Adjustment of the angle of inclination of the lever 1 in the longitudinal direction;
Adjustment of the angle of inclination of the lever 1 in the transverse direction;
Adjusting the telescopic locking device. To adjust the angle of inclination of the lever in the longitudinal direction:
Set the lever 2 to the neutral position by tightening the neutral position lock on the shift mechanism 20 (for the YaMZ gearbox - 238M).
Check the neutral position of the gearbox by moving the roller of the lever 2 in the axial direction by pressing it by hand. In this case, the roller should move by an amount of 30 - 35 mm;
Loosen the tightening of the bolts 17 and by longitudinal movement of the plate 16 set the angle "a" 90 degrees;
If the travel of the plate 16 is insufficient, loosen the bolts 5, move the rod 6 relative to the shank 4, tighten the bolts 5 and repeat the angle adjustment "a" by moving the plate 16.
Adjustment of the lever 1 in the transverse direction is carried out by changing the length of the lateral rod 3 by disconnecting one of the tips with unscrewing the nut of its fastening, followed by adjusting the length so that the lever 1 takes a vertical position.
After adjustment, return the neutral position lock to its original position (for the YaMZ gearbox - 238M).
Adjustment of the telescopic mechanism locking device should be done as follows:
Unpin the pin, unscrew the nut, remove the pin and disconnect the rod 6 from the fork 9 of the gear lever;
Loosen the lock nut 13 and unscrew the shank 14 up to the thread stop;
Push the inner rod 6 up to the stop of the earring projections into the grooves of the tip 15;
Keeping the mechanism compressed, screw in the shank 14 until the mechanism is locked by the sleeve 10 under the influence of the spring 11;
Tighten the lock nut 13, check the accuracy of the locking mechanism. When the mechanism is locked, the axial and angular play must beminimal. In the unlocked position (bushing 10 is shifted to the right), the internal link should be pushed out by the return spring by 35 - 50 mm. Further movement of the extension should be smooth, without jamming and the locking mechanism should ensure that the extension rod is clearly fixed in its original position.
Avoid bending and bending of the drive rod and its telescopic components. Adjust the gearbox drive with the engine off.
Figure 21. Gearbox control drive
1,2 - lever; 3, 4, 6 - thrust; 5, 7, 17 - bolt; 8 - finger; 10 - bushing; 11 - spring; 12 - earring; 13 - nut; 14 - shank; 15 - tip; 16 - plate; 18 - switch 19 - ball; 20 - switching mechanisms
Cardan transmission
Cardan drive of MAZ cars - 544020, 544069, 544008, 544005, 544004, 544003 consists of one cardan shaft(Figure 22), MAZ vehicles - 643068, 643069, 643008 from two shafts: the drive of the middle axle (Figure 22) and the drive rear axle(Figure 23).
Cardan transmission of MAZ cars - 534008, 534005, 53404, 534003 - of two cardan shafts(Figure 22) with a promoter, cardan transmission to the MAZ-631208 car consists of cardan transmission drive of the middle axle, consisting of two shafts (Figure 22) with a promoter and a propeller shaft (Figure 23) of the rear axle drive.
The flanges of the propeller shafts are made with cross-shaped face splines.
The universal joint shaft joints have a continuous lubrication system for the needle bearings. They are lubricated through a corner nipple.
At the next service, old grease, wear debris and excess fresh grease are removed through the gland seal of the bearings.
The spline connection has a seal with a ring 5 located in a tubular cage that covers the splines.
The spline joint is lubricated through nipple 4 (Figure 23) and nipple 2 (Figure 22).
The propeller shaft assembly is dynamically balanced by welding the plates 3. The radial runout of the propeller shaft assembly must not exceed 1 mm. The cardan drive is balanced as an assembly.
Cardan transmission care
At each maintenance - 1 check the condition of the fastening of the propeller shaft flanges and needle bearing caps.
If, when wiggling the flanges - forks of the propeller drive, a loosening of the flanges of the output shaft of the gearbox or the drive gear of the reducer of the middle (rear) axle is detected, disconnect the corresponding flange of the propeller shaft, unpin the nut of the flange of the gearbox or drive axle, tighten it and re-cotter it.
The fastening bolts of the propeller shaft flanges must be tightened to a torque of 160 - 200 Nm (16 - 20 kg.cm). Replacing the flange connection bolts with thermally untreated ones is not allowed.
It is also not allowed to exceed the tightening torques of the bolts, as this can damage them.
Periodically, it is necessary to check for a noticeable backlash in the spline joint, between the crosspiece and the needle bearings.
When loosening the cover bolts 8 (Figure 22), bend the lock plate and tighten the bolts to a torque of 27 - 39 Nm (2.8 - 4.0 kgf.cm), then bend the lock plate to one of the bolt heads.
Tighten the mounting bolts of the promoter with a torque of 120 - 160 N.m. It is allowed to disassemble the hinges only in case of failure of bearings, seals, crosses.
Periodically clean the outer surfaces of the propeller shaft and joints from dirt, especially the grease nipple heads and the hole in the plug of the sliding fork. If the plug is lost, it must be reinstalled to protect the splined joint from dirt.
Strictly observe the frequency of lubrication operations and the suitability of the grease used for the cardan drive (bearings, spline joints).
When assembling the propeller shaft or replacing it with a new one, its splined connection must be assembled in such a way that the holes of the forks located on the propeller shaft are always located in the same plane. To do this, align the arrows stamped on the shaft tube and on the sliding fork.
To avoid damage to the joint seals, do not use a spudger or other objects inserted into the joint fork to rotate the propeller shaft. It is recommended to use a special puller to disassemble the hinge. Reinstalling damaged mechanical seals into the joint is not permitted.
When assembling the hinge, mechanical seals are pressed onto two adjacent spikes of the cross, after which it is inserted into the fork (flange). Install the rest of the mechanical seals on the studs through the bearing holes on the forks (flanges) and press them onto the seating strips of the studs. To press the mechanical seal onto the spike seat, use a special mandrel.
Leading bridges
Rear axle. It has a double spaced main gear, consisting of a central bevel gearbox and planetary wheel gears located in the wheel hubs (Figures 24, 25).
Medium drive axle. Consists of a central gearbox (Figure 26) and planetary wheel gears. The cross-axle differential and wheel transmissions of the middle axle are maximally unified with similar units of the rear axle.
The drive of the mechanism for blocking the center-axle and cross-axle differentials of the middle axle is electro-pneumatic.
The blocking of the cross-axle differentials of the middle and rear axles is carried out by one switch, regardless of whether the blocking is activated center differential.
The locked position of the differentials is signaled by control lamps.
The blocking of interwheel and inter-axle differentials should be turned on when overcoming difficult and slippery road sections when the vehicle is stopped or when driving at low speed (up to 10 km / h) and turn off the blocking at sharp turns of these road sections. Locking is not allowed in wheel slip mode.
Driving axle maintenance. It consists in maintaining the required level of lubrication in central gearboxes and in wheel gears, changing it in time, cleaning the breathers from contamination, checking and tightening fasteners, checking the operating noise and heating temperature of the axles, as well as adjusting the gearing of bevel gears and preloads in tapered bearings ...
If a grease leak is detected through the cups of the input and output shafts of the middle axle and the drive gear of the rear axle, the cause of the leak should be found out.
If the oil seals are worn out, replace them with new ones. Replace in the following sequence:
Disconnect the propeller shaft from flange 14 (Figure 24);
Undo the cotter pin and unscrew the nut 15 for fastening the flange, remove the O-ring 16 and the flange 14;
Unscrew the fastening bolts 13 and remove the cover with cuffs;
Replace the cuffs by filling their internal cavities with Litol - 24 grease and reassemble the unit in the reverse order of disassembly.
Cuffs 14, 42 (Figure 26) and 17, 18 (Figure 24) are pressed into the covers until they stop.
Tighten the flange mounting nuts while checking the minimum torque value and then tightening until the shaft bore coincides with the nut slot.
In this case, the turning moment of the leading bevel gear should be in the range of 0.1 - 0.3 kgf.m.
Adjust the tension of the bearings of the drive bevel gears, axle differentials and the output shaft of the middle axle after 60-80 thousand km of run (see Adjustment of the central gearbox) while tightening the nut 15 of the flange 16 (Figure 26).
After 180 thousand km, at the next MOT - 2, the crankcase of the axles should be flushed. Removal of the central bevel gearbox for adjustment work should be carried out in the following sequence;
Drain the oil from the axle housing and wheel gears (after removing the drain and filler plugs);
Disconnect the propeller shaft;
Disconnect the air supply hose from the gear blocking cylinder, disconnect the pressure sensor terminals, unscrew the sensor;
Remove the covers 23 (Figure 25) of the wheel gears;
Block the cross-axle differential (using a bolt);
Take out the axle shafts 13 together with the driving gears 27 of the wheel gears;
Unscrew the nuts of the studs securing the gearbox to the axle housing (except for the two upper ones).
After that, roll the cart with the lift under the gearbox and, ensuring the reliable support of the gearbox on the lift, unscrew the remaining two upper nuts. Then, using two dismantling bolts in the flange of the gearbox to the axle housing, remove the gearbox. The assembly is carried out in the reverse order.
When disassembling a wheel drive:
Drain the oil from the wheel drive by installing the wheel so that the drain plug is in the lowest position, unscrewing the drain and filler plugs 21, 24 (Figure 25);
Unscrew nuts 2 and remove cover 23;
Take out the axle shaft 13 together with the drive gear 27;
Unscrew the bolts and remove the brake drum 10;
Remove the carrier body together with the satellites 28 and the carrier 22;
Unscrew the lock nut 19 with a special wrench, remove the lock washer, unscrew the nut 17 and remove the driven gear 20 together with the hub 18;
Remove hub 5 with bearings.
Assemble the wheel drive in the reverse order. The axles of the satellites must be installed with their flats facing the center of rotation of the wheel drive.
When removing the wheel hub, the wheel train must be disassembled in the same sequence.
When removing axle shafts 13 (Figure 25) and 36, 54 (Figure 26) without dismantling the central gearbox, it is imperative to lock the cross-axle differentials of the rear and middle axles and unlock them only after installing the above axles.
Adjustment of the central gear. Adjust when removed gearbox in the following sequence:
Adjust the tension of the tapered bearings of the driving bevel gear;
Adjust the tightness of the differential bearings;
Adjust the meshing of the bevel gears according to the contact patch and lateral clearance, and then (if necessary) adjust the tension of the differential bearings.
Figure 24. Rear axle reducer
1 - cylinder of the locking mechanism, 2 - piston; 3 - screw; 4 - nut; 7 - plug for switching on the locking mechanism; 8 - gearbox housing; 9 - driven gear; 10,12,26,32 - bearing, 11 - bearing cup; 13 - bolt; 14 - flange; 15 - nut; 16 - sealing ring; 17, 18 - cuff; 19 - gasket; 20 - adjusting gaskets; 21 - oil deflector; 22 - driving gear; 23 - satellite; 24, 31 - differential cup; 25, 33 - nut; 27, 29 - semi-axle gear; 28 - crosspiece; 30 - support washer; 34 - differential lock clutch; 35 - bridge housing
At the same time, in order to avoid disturbing the initial bearing adjustment, nuts 25, 33 (Figure 24) should be unscrewed and screwed at the same angle.
To adjust the pinion pinion bearings:
Remove the drive bevel gear with bearing cup assembly.
To do this, unscrew the fastening nuts in the rear axle gearbox housingcup 11 bearings and with the help of dismantling bolts remove the cup with gears.
In the gearbox of the middle axle, unscrew the bolts of the gear housing and, using the dismantling bolts, remove the gear housing assembly with the input shaft, bend the locking plates, unscrew the nuts securing the intermediate housing and remove it assembled with the drive bevel gear;
Determine with the indicator the axial clearance in the bearings;
Fasten the drive gear in a vice (protecting it from damage with soft metal gaskets);
Remove flange 14 (Figure 24), cover with cups 17, 18 or gear 9 (Figure 26), inner ring of the bearing closest to the shank and shim 20 (Figure 24);
Measure the thickness of the shim and calculate the required thickness to eliminate the axial play and obtain a preload of the bearings (the decrease in the thickness of the gasket should be equal to the sum of the axial play measured by the indicator and the value of the bearing preload equal to 0.03-0.05 mm);
Grind the shim to the required size and assemble the drive gear without securing the cover with collars.
Figure 25. Wheel drive of the drive axle
1 - satellite axis; 2 - nut; 3 - needle bearing; 4.7 - bearing: 5 - hub; 6.8 - bolts; nine - ABS sensor; 10 - brake drum; 11 - shield; 12 - axis; 13 - semiaxis; 14 - expanding fist; 1 5 - brake shoe; 17, 19-nut; 18-driven gear hub; 20 - driven gear; 2! - drain plug; 22 - carrier; 23 - cover; 24 - filler plug; 25 - biscuit; 26 - half-axis stop; 27 - driving gear; 28 satellite
Figure 26. Middle axle gearbox
1.12 - satellites; 2.50 - support washers; 3.17 - adjusting gasket; 4.23 - driving gear; 5,7, 13, 18, 29, 31, 39, 51 - bearing; 6 - spacer sleeve; 8, 24, 25, 30, 38 - adjusting washers; 9 - driven gear; 10 - gear housing; 11, 15, 34, 44, 52 - nut; 14, 42 - cuff; 16, 43 - flange; 19, 45 - cover; 20 - interaxle differential lock clutch; 21 - ring; 22 - retaining ring; 26, 48 - differential crosses; 27 - center differential; 28 - axle drive shaft; 32 - cylinder of the locking mechanism; 33 - screw; 35 - rear axle drive shaft; 36, 54 - half-shafts; 37 - interwheel differential lock clutch; 40 - a glass of bearings; 41 - bolt; 46 - driven gear; 47 - interwheel differential; 49 - semi-axle gear; 53 - nut stopper; 58 - ring
Adjusting the meshing of the bevel gears of the central gearbox
Table 3
When tightening the flange nut, the bearing cup should be turned to correctly position the rollers in their casings;
Check the bearing preload according to the value of the bearing cup turning moment, which should be equal to 1 - 3 N.m (0.1 - 0.3 kgf.m).
With normal preload in the bearings, remove flange 14 (Figure 24), reinstall the cover with collars 17, 18 and finally assemble the assembly.
Adjust the tension of the differential bearings with the drive gear removed using nuts 25 (Figure 24) and 52 (Figure 26).
Tighten the nuts to the same depth until the desired preload is obtained, without disturbing the position of the driven gear.
Bearing preload is determined by the torque required to turn the differential, which should be within 2-5 N.m (0.2-0.5 kgf.m) with the drive gear removed. This moment is determined by a special torque wrench or by measuring the force applied at the radius of the differential cups and equal to 23 - 57 N (240 - 586 kgf).
The procedure for checking and adjusting the meshing of bevel gears is as follows:
Before installing the bearing cup with the drive gear in the gear case, wipe the teeth of both bevel gears and apply a thin layer of paint on the side surfaces of three to four teeth;
Referring to Table 3, adjust the meshing of the bevel gears. The movement of the drive gear is ensured by changing the number of shims under the flange of the drive gear bearing cup.
To move the driven gear, use nuts 25 (Figure 24) or 52 (Figure 26), so as not to disturb the preload adjustment in the differential bearings, screw (unscrew) the indicated nuts at the same angle.
Adjust bearings 13 (Figure 26) in the following sequence:
Disconnect propeller shaft from flange 16;
Remove the differential lock mechanism;
Unscrew the bolts of the gear housing and remove the crankcase assembly with the center differential;
Disassemble the center differential, remove the drive gear and remove the bearings from the gear;
Rinse the parts in diesel fuel and lubricate before assembly;
Install the inner bearing into gear 23 until it stops;
Install outer race 21, inner race 58 and outer race of the outer bearing;
To ensure a preload in the bearings, reduce the thickness of the set of washers 24 by the value of the axial clearance plus 0.02 - 0.03 mm and install them in place;
Install circlip 22;
Install the inner bearing race complete with the cage.
To check the preload in the bearings, install the gear 23 with bearings on the press table, through a mandrel (supported on the end of the inner race of the inner bearing) and compress the bearings with a slight effort. Swing to check the presence of axial play and the ease of turning the gear.
A cross 26 and a spacer sleeve assembled with a gear can be used as a mandrel.
The turning force of the driving spur gear applied on its outer diameter should be in the range of 5.5 - 22 N (0.55 - 2.2 kgf).
The bearings 39 of the output shaft 35 can also be adjusted by changing the set of shims 38 in the following sequence:
Unscrew the bolts 41 and remove the output shaft 35 with the bearing cup 40;
Rinse parts in diesel fuel, lubricate before assembly;
Clamp the shaft in a vice, install the inner race of the inner bearing with a cage on the shaft;
Install glass 40 assembled with outer bearing races;
Install the required set of shims 38, the thickness of which should be reduced by the value of the axial clearance plus 0.02 - 0.03 mm;
Install the cage and the inner race with the outer bearing;
Fit flange 43, tighten nut. By swinging and turning on flange 43, check for axial play.
The turning force applied at the radius of the holes in the flange should be in the range of 6.4 - 25.5 N. (0.65 - 2.6 kgf).
After adjustment, unscrew the nut and remove the flange 43, install the cover 45 with the collars 42 and, having assembled the assembly, tighten the flange nut. In this case, the holes for the cotter pin must coincide with the slot in the nut. Then pin the nut, reinstall the shaft with bearing unit and flange assembly.
The thickness S of the package of gaskets 17 (Figure 26) for adjusting the preload of tapered bearings 18, 31 when compressed by their force P = 800N, is determined by the formula: S = (H - P ± 0.1) ± 0.05mm.
Adjustment of the lateral clearance in the meshing of the center differential gears is carried out using a set of washers 25, 30. With a compression force of 800N, it should be within 0.1 - 0.55 mm.
Before assembling the gearboxes of the rear and middle axles, a layer of LOCTITE 5900 sealant or similar should be applied to one of the mating surfaces, as well as between the gaskets in connectors B (Figure 24) and in connectors C, D, E (Figure 26).
Adjustment of locking mechanisms for interwheel and center differentials
Adjustment of the rear axle cross-axle differential locking mechanism is carried out on the assembled central gearbox, before installing it in the axle housing, in the following order (Figure 24):
Measure the gap A between the end of the clutch 34 and the differential cup, the value of which should be A = 1 + 0.3 mm. In this case, the sleeve 34 must be held coaxially with the cup 31 by means of a mandrel;
Unscrew the bolts of the locking mechanism cylinder 1 and remove it together with the piston;
Having unscrewed the nut 4 of the plug stem screws, tighten or unscrew the screw 3 by the amount of the required fork movement to ensure the clearance A = 1 + 0, 3mm, tighten the nut 4 to a torque of 44 - 56Nmm and install the cylinder.
Adjust dimension A = 1 + 0.5mm (Figure 26) of the center differential lock mechanism using shims 56. Adjust dimension B = 1 + 0.5mm using screw 33. After adjustment, tighten nut 34 to a torque of 44 to 56 Nm (4.4 - 5.6kGs.m).
Rear wheel hub bearing adjustment
Raise the axle and release the wheels from the load.
Check the free rotation of the wheel by hand, if there is no axial play of the hub.
If the wheel rotates tightly or axial play of the hub is detected, adjust the bearings, checking at the same time the serviceability of the cuffs for the absence of oil leaks.
Adjust the bearings in the following order:
Drain the oil from the wheel drive;
Disassemble the wheel drive as described above;
Turning the hub, tighten nut 17 (Figure 25) to a torque of 400 - 500 Nm (40 - 50 kgf.m), then unscrew it 60 - 75 degrees and check the hub for ease of rotation. It should rotate freely by hand, axial play is not allowed; - install the washers, tighten the lock nut 19 to a torque of 392 to 490 Nm (40 - 50 kgf.m) and lock it by bending the lock washer mustache;
Check again the rotation of the hub and the absence of axial play.
The correctness of the adjustment is determined by the mileage of the car according to the degreeheating the hub, the temperature of which should not exceed 60 ° C (at higher temperatures, the hand cannot withstand prolonged contact). Tightening torques threaded connections driving axles are shown in table 4.
Table 4. Tightening torques of threaded connections of driving axles
|
Compound |
Moment, N.m |
Rear axle |
Middle bridge |
Note |
|
1. Mounting bolts: |
||||
|
Trunnions to the casing of the bridge |
320-360 |
+ |
||
|
Drove to the body of the carrier |
400-440 |
Drive axles disc, wheels |
||
|
Bevel gear bearing cups |
90-120 |
+ |
Bolt-on option |
|
|
Gearbox yoke covers |
200-280 |
+ |
||
|
Brake chamber bracket |
400-440 |
+ |
* with the upper arrangement of energy storage devices |
|
|
Brake chamber bracket |
118-157 |
at the bottom arrangement of energy storage devices |
||
|
Compound |
Moment, N.m |
Rear axle |
Note |
|
|
1. Mounting bolts: |
||||
|
Expansion cam supports |
118-157 |
+ |
+ * |
* with the upper arrangement of energy accumulators |
|
Expansion cups |
118-157 |
+ |
+ |
|
|
Center differential cups |
65-80 |
+ |
||
|
Gear casing to intermediate casing |
50-62 |
+ |
||
|
Seal caps to hub |
24-36 |
+ |
+ |
|
|
Cuff covers input shaft middle bridge |
50-62 |
+ |
||
|
Caps for cuffs of the output shaft of the middle axle |
44-56 |
+ |
||
|
Rear axle bearing cup caps |
50-62 |
+ |
||
|
Differential nut stopper |
12-18 |
+ |
+ |
|
|
Retaining plates for brake shoe axles |
24-36 |
+ |
+ |
|
|
2. Fastening nuts: |
||||
|
Reducer to the crankcase of the bridge |
120-160 |
+ |
||
|
Driven spur gear |
450-600 |
+ |
||
|
Flanges |
450-600 |
+ |
+ |
|
|
Driven gear and cups interwheel differential |
210-260 |
+ |
+ |
|
|
Wheel Drive Covers |
24-36 |
+ |
||
|
Wheel hubs |
400-500 |
+ |
+ |
|
|
Cup of the driving gear of the middle axle |
130-180 |
+ |
||
|
Bearing cups of the driving bevel gear of the rear axle |
90-120 |
+ |
For stud mounting option |
|
|
Hub locknuts |
400-500 |
+ |
+ |
|
|
Adapters and nuts for fastening shields of brake mechanisms |
24-36 |
+ |
+ |
|
|
Locking the cross-axle differential lock screw |
44-56 |
+ |
+ |
|
|
Intermediate crankcase of the middle axle |
70-100 |
+ |
||
|
Wheel disc |
250-300 |
+ |
+ |
|
|
Ball finger |
275-314 |
|||
|
Pivot Adjustment Bolt Lock Nuts |
216-275 |
+ |
||
.. 160 161 ..
MAINTENANCE OF THE YAMZ-236 GEARBOX
During maintenance, check the attachment of the gearbox to the engine and the condition of its suspension, maintain normal level oil in the box and replace it in a timely manner during TO-2.
The oil level in the gearbox housing must not be lower than the lower edge of the control hole 3 (Fig. 122). Drain the oil from the gearbox housing while hot through the drain hole closed by the plug 4. After draining the oil, clean the drain plug magnet. After draining the oil, unscrew the bolts and remove the cover 2 of the intake of the oil pump, clean and rinse the mesh, and then reinstall the cover. When installing the intake cover, take care not to block the oil line with the cover or its gasket.
Rice. 122. JamZ-236P gearbox plugs:
1-oil filler hole; 2-oil pump intake cover;
3-control hole for oil level; 4-drain hole
Wash the gearbox with industrial oil I-12A or I-20A in accordance with GOST 20199 - 88; 2.5 - 3 liters pour it into the crankcase, set the gear lever to neutral, start the engine for 1 ... 8 minutes, then stop it, drain flushing oil and pour in fresh. It is strictly forbidden to flush the gearbox with kerosene or diesel fuel in order to avoid the failure of the oil pump due to insufficient suction vacuum and, as a result, failure of the gearbox. In the event of a complete transmission overhaul oil pump Lubricate with gearbox oil prior to installation.
When towing a vehicle with the engine off, the primary and intermediate shafts the gearboxes do not rotate, the oil pump in this case does not work and does not supply lubricant to the bearings of the gears of the output shaft and to the tapered surfaces of the synchronizers, which will cause scuffing of the sliding surfaces, wear of the synchronizer rings and leads to the failure of the entire gearbox. To tow, disengage the clutch and engage direct (fourth) gear in the gearbox or disconnect the gearbox from the transmission.
Towing a car over a distance of more than 20 km without disconnecting the propeller shaft or squeezing the clutch with the direct drive engaged is not allowed.
To prevent premature wear of rubbing pairs, it is recommended before starting the engine at a temperature the environment below - 30 ° C, warm up the gearbox. If this is not possible, then drain the oil from the crankcase during a long stop of the engine, and before starting the engine, heat this oil and pour it into the box through the hole in the top cover.
For smooth and easy gear shifting and protection of the countershaft teeth and gears of the first gear and reverse gear from end wear, as well as protecting the rings. synchronizers from wear to correctly adjust the clutch and not allow it to "run".
Page 1 of 2
1. The use of contaminated oils is not allowed.
2. It is not allowed to engage the transfer in the main box until the selected range of the range is turned on, that is, until the control lamp lights up when the slow range is turned on or until it goes out when the fast range is turned on.
Demultiplier switching time 0.5-1.0 sec.
3. When the car is moving, it is strictly forbidden to engage the first gear in the main gearbox when the fast range of the range is engaged.
4. Engage first and reverse gear only after the vehicle has come to a complete stop and when the slow range is engaged in the range.
5. It is not allowed to include a slow range of the range multiplier when the vehicle speed is higher than the minimum speed specified in table 1.
6. It is not allowed to change gears while the car is moving with the power take-off switched on.
7. It is not allowed to increase the speed of the engine when braking the car with the engine, in excess of the maximum idle speed.
8. The maximum temperature of the oil in the gearbox is 120˚С. Short-term operation (no more than 2 hours) is allowed at oil temperatures up to 145˚С.
Preparing the transmission for work
Before operation, it is necessary to check the connection of the transmission control systems to the corresponding vehicle systems;
Pneumatic control system for the demultiplier to the pneumatic valve of the gearshift mechanism located in the gearshift lever, and the reducing valve to the pneumatic system of the vehicle;
Power supply automatic system blocking of electronic-pneumatic type (АСБП) to the car wiring diagram;
Power supply of the control lamp for switching on a slow gear in the range multiplier and for switching on the reverse gear to the vehicle's electrical system;
The lever of the shaft of gear shifting to the drive of the transmission control.
Check the oil level in the gearbox by unscrewing the plug with the level indicator from the filler hole located on the right side of the gearbox housing, and then insert the plug with the indicator into the hole until it stops in the thread. The oil level should be at the top mark on the gauge. After checking the oil level, screw the plug into the hole.
Check the operation of the ASBP, for which first make sure that when the slow gear is engaged in the demultiplier, the control lamp is on, and when switching to fast gear, it goes out. Shift gears in the range switch with the range switch located on the gear lever knob, with an air pressure in the car's pneumatic system of at least 450-490 kPa (4.5-4.9 kgf / cm²).
Accelerate the car to a speed 5-10 km / h higher than the maximum speed indicated in table 1.
According to the table, determine the maximum speed for each vehicle, depending on the rear axle gear ratio and the tires installed on the vehicle.
Squeeze the clutch, disengage the gear in the main gearbox, engage a slow gear in the range multiplier and monitor the warning lamp and vehicle speed.
If the changeover occurs immediately (the control lamp will light up) after engaging a slow gear in the range multiplier at a speed higher than the maximum speed specified in Table 1, the ASBP is faulty. In this case, without releasing the clutch pedal, reduce the speed by 5 km / h below the minimum specified in Table 1, and then switch.
If the inclusion of a slow transfer in the range occurs when the vehicle speed is below the minimum specified in table 1. - the ASBP is working properly.
Check the operation of the pneumatic blocking of the first gear and reverse gear in the main gearbox in the following sequence;
Set the gear shift lever to neutral;
Switch on a slow gear in the range and make sure that the force on the head of the gear shift lever when moving it towards the engagement of the first gear and reverse gear is 5-10 kg;
Switch on fast gear in the range and check the force on the head of the gear shift lever when moving it towards engaging the first gear and reverse; the effort should be 4-5 times greater compared to engaging in slow gear in the demultiplier.
Maintenance
Maintenance work is mandatory and must be carried out strictly on time.
Maintenance of the gearbox by frequency and work performed is divided into the following types:
Daily maintenance (EO);
Maintenance after running-in the car (1000 km of run);
First maintenance (TO-1);
Second maintenance (TO-2).
The frequency of maintenance of the gearbox (TO-1 and TO-2) corresponds to the frequency of maintenance of the vehicle on which it is installed.
During maintenance, it is necessary to ensure conditions that exclude the ingress of dust and dirt into the gearbox assemblies.
Daily maintenance
Check by visual inspection for signs of oil leakage from the gearbox. Check the tightness of the pneumatic range control system.
Air leaks are audible. Alternately moving the range switch to the up and down positions, listen to the air ducts with the lever in the neutral position in the main box and with any gear engaged.
If oil or air leaks are found, identify the cause and correct the malfunction.
Maintenance after vehicle break-in
After running in the car, drain the oil from the gearbox housing, clean the drain plug magnet from metal particles, clean the cover installed on the bottom of the lower crankcase from wear debris.
Drain the oil from the box immediately after hot work.
After draining the oil, rinse the box crankcase with liquid industrial oil, for example, I-12A or I-20A in accordance with GOST 20799-88. Do not flush the transmission with diesel fuel or kerosene. Fill in fresh oil up to the upper mark on the dipstick.
First maintenance (TO-1)
Check oil level and top up if necessary.
Change the oil in the gearbox with the maintenance operations after the vehicle has been run-in.
Clean and lubricate with Litol-24 grease the spool, the piston, the inner surfaces of the air distributor cylinders, the piston cups and the inner surfaces of the range switch cylinder.
Check the operation of the ABSP.
Check the air pressure at the outlet of the pressure reducing valve, which should be within 450-500 kPa (4.5-5 kgf / cm²).
Check the tightness of the pneumatic control system of the range multiplier, eliminate the detected air leaks by tightening the bolts or replacing the sealing washers.
Transmission oils approved for use in the gearbox and the recommended viscosity grades of transmission oils depending on the ambient temperature, ° C, are shown in Table 2.
1. At an ambient temperature below minus 20˚C, it is allowed to use a mixture of transmission oil (85%) approved for use with diesel fuel of grade "A" or "Z" (15%).
2. Oil MT-16P gost 6360-83 is allowed for use in a gearbox with a halved replacement period.
3. It is allowed to use imported gear oils with API performance level of at least GL-4, viscosity class according to Table 2.
The checkpoint at YaMZ 2361 is mechanical (5 steps), equipped with synchronizers in several gears. This device produced by Yaroslavsky motor plant... They are equipped with MAZ heavy vehicles. Depending on the configuration, YaMZ can be found on Ural cars, MARZ buses.
Gearbox appearance
The main specifications transmission systems.
An assembly such as a gearbox on the YaMZ 236 is equipped with a clutch housing made of reliable materials. The amount of fuel in the crankcase of the high-speed box is about 5.5 liters. The transmission system includes heavy-duty input shaft... The secondary shaft of the gearbox at YaMZ 236 rests with one part on the existing bearing (roller), the other on the ball bearing. It should be noted that there are intermediate shaft bearings on the roller bearings.
Longitudinal section of the gearbox
There is a special creeper. Thanks to him, it is possible to reduce the speed limit. The oil pump is distinguished by its efficiency. The oil intake is covered with a mesh. This element has a magnet, which is necessary to attract metal microparticles that may be present in the oil. This system also includes a pressure reducing valve. Its main function is to maintain the outlet pressure at an optimal level during movement.
Scheme of the YaMZ checkpoint
In the upper cover of the YaMZ 236 gearbox there is a mechanism that provides a shift when moving speed modes... It is characteristic of special equipment that a box (KOM) is installed, designed for a long service life. On a number of trim levels, there is an electronic speedometer drive.
Gearbox cover diagram
The weight of the gearbox together with the crankcase exceeds 240 kg. While the weight power unit YaMZ 236 reaches 1000 kg. Add oil to the YaMZ 236 gearbox through a special hole, which is securely closed with a plug.
Possible breakdowns
Malfunctions of the gearbox on the YaMZ 236 can be of the following plan:
- the appearance of extraneous noise;
- reducing the amount of oil that is poured into the box;
- difficult inclusion of speeds;
- spontaneous shutdown of speed modes;
- fluid leaks from the side of the crankcase.
For any of these manifestations, it is advisable to independently check the oil level in the box, how firmly all fastening nuts and bolts are tightened. If this is not the problem, the vehicles should be sent for diagnostics to a service center. Here, the craftsmen must, using special equipment, check the integrity of the gearbox components (couplings, bearings, bushings, etc.), assess the operating ability of the oil pump.
