On MAZ-64227, MAZ-54322 vehicles, an eight-speed dual-range gearbox YaMZ-238A is installed with synchronizers in all gears, except reverse
The gearbox consists of a main two-stage gearbox and a two-stage additional gearbox (downshift).
The gearbox device is shown in fig. 1. Installation of all parts of the gearbox is carried out in the crankcases of the main and additional boxes, which are interconnected, and then assembled to the clutch housing: a single power unit is formed as part of the engine, clutch and gearbox.
The primary shaft 1 of the main box is mounted on two ball bearings; driven clutch discs are installed on the front splined end, and the rear end is made in the form of a ring gear of the constant mesh gear of the main box.
The output shaft 5 of the main box in front rests on a cylindrical roller bearing mounted in the bore of the gear rim of the drive shaft, and at the rear on a ball bearing mounted in the front wall of the crankcase of the additional box.
The rear end of the secondary shaft is made in the form of a ring gear, which is a gear of constant engagement of the additional box.
The gears of the second and fourth gears of the output shaft of the main box are mounted on plain bearings made in the form of steel bushings with a special coating and impregnation, and the gears of the first gear and reverse gear are mounted on roller bearings.
The intermediate shaft 26 of the main box in front rests on a roller bearing mounted in the front wall of the main box crankcase, and at the back - on a double-row spherical bearing placed in a cup installed in the rear wall of the main box crankcase.
In the tides of the crankcase of the main box, an additional axle is installed for the reverse intermediate gear.
The reverse gear is switched on by moving the reverse carriage 24 forward until it is connected to the ring gear of the reverse gear 25, which is in constant engagement with the reverse intermediate gear.
The secondary shaft 15 of the additional box in front rests on a cylindrical roller bearing located in the bore of the gear rim of the secondary shaft of the main box, at the back on two bearings: a cylindrical roller bearing and a ball bearing, installed respectively in the rear wall of the crankcase of the additional box and the output shaft bearing cover.
On the splines of the middle part of the secondary shaft of the additional box, gear shift synchronizers are installed, and on the rear splined end there is a flange for fastening the cardan shaft.
On the middle cylindrical part of the shaft, on roller cylindrical bearings, gear 11 of the additional box is installed.
The intermediate shaft 19 of the additional box rests at the front on a cylindrical roller bearing mounted in the front wall of the additional box crankcase, and at the rear on a double-row spherical bearing placed in a glass mounted in the rear wall of the additional box crankcase. Downshift gear 22 is installed on the front splined end of the intermediate shaft of the additional box.
At the rear of the intermediate shaft, a ring gear is made, coupled with the downshift gear of the secondary shaft of the additional box.
To switch gears in the main box, inertial synchronizers with conical friction rings are used, and in the additional box - with friction discs.
Gear shifting in the main box is performed using a mechanical remote drive, and the additional box is controlled using a pneumatic drive.
The MAZ gearbox is equipped with five ranges, it aggregates with a YaMZ-236 diesel engine. It has an accelerating range and a remote control. There are also several other modifications of this node. To activate the second and third speed, the synchronizer is activated. Consider the device of this car block and its features.
Essential elements
The MAZ gearbox includes a primary shaft with a gear mounted on a crankcase with ball-type bearings. In addition, there is an intermediate shaft. From the front it looks like a device on a cylindrical roller bearing, and from the back it looks like a ball analog. The rear element compartment is protected by a cast iron cover, the first and reverse gears are cut directly on the shaft, and the rest of the ranges and power take-off are carried out through keyed drive gears.
The MAZ gearbox with a demultiplier is equipped with an intermediate shaft drive gear with a damper damper. This allows you to reduce the vibrations transformed from the power unit to the transmission box. In addition, this solution makes it possible to reduce the noise of the gear at idle. The need to install the absorber is due to the insufficient uniformity of the operation of the YaMZ-236 type motor.
The gear tooth is made separately from the hub. It is disconnected using six cylindrical springs. Residual vibrations are damped by deformation of the spring elements and friction in the damper assembly.
Device
An axle with a pair of roller bearings and a reverse gear is installed on the side between the intermediate and secondary shaft. The front gear element aggregates with the analogue of the first speed using an additional shaft, and the rear gear is engaged by activating the reverse gear.
On the MAZ semi-trailer, the front part of the secondary shaft is mounted on a roller bearing, and the rear element is installed in the ball bearing bath. On the protruding part there is a speedometer drive gear, at the back the part is protected by a cover in which the oil seal and the speedometer drive are located. On the splined rear of the shaft, a mechanism for switching first and reverse gears is installed. It should be noted that this gear is equipped with straight teeth.
Peculiarities
On the secondary shaft of the MAZ gearbox, the gear sliding structure is freely installed on steel bearings. This includes adjusting second, third and fifth speeds. The elements are protected from longitudinal displacement by means of oblique teeth and thrust rings. Three gears have constant engagement with the intermediate shaft. The gears are made with a conical base and an internal toothed surface.
The synchronizers are located between the gear elements of the second and third speeds. They provide noiseless gear shifting. The synchronizer itself consists of a clutch, which is located on the splines of the rear sleeve, as well as a body with bronze sealing rings. The skeleton aggregates with the coupling by means of ball-type retainers. The clutch is provided with toothed rims. Her fingers pass through special sockets, rings with pins and a switching fork are attached to them from the outside.
Checkpoint MAZ "Zubrenok": work
During operation of this unit, the housing ring of the housing is pressed against the cone by the gear. In this regard, friction between the contacting surfaces causes rotation and installation of the cavity on the slot with the coupling pin, while the element is blocked by the housing.
The body then engages with the gear cone due to the resulting force applied to the shifter. After the effect of friction occurs between the speed cones and the gear with the clutch, the load forces are leveled and the locking device releases the clutch from the base of the synchronizer. Next, the clutch moves by extruding the balls of the locking device, which is shifted to the side. Then the ring gear of the assembly engages with the internal teeth of the mechanism, which entails the inclusion of one or another gear.
Functioning scheme
There are three adjusting rods in the crankcase cover tidal sockets. Their forks are aggregated with the first and reverse gear control carriage, as well as with a pair of clutch synchronizers. Switches are equipped with ball locks and locks.
The diagram of the MAZ gearbox, presented below, confirms that the most loaded bearings receive lubrication under the resulting operating pressure. The oil comes from the bath through a detachable filter element. It is equipped with a magnet that allows liquid to enter by suction of the gear pump. This unit is driven by the front edge of the intermediate shaft. Next, the mixture is pumped through a groove in the crankcase, enters through the channel of the primary and secondary shafts into the gear bearings of the mechanism. The remaining elements are lubricated by spraying the incoming oil.
Oil pump
The MAZ-4370 gearbox is equipped with an oil pump, which has a ball valve that serves to limit the oil pressure in the gearbox system. The assembly crankcase is equipped with an internal baffle, which causes the waste oil to be released through two holes blocked by special plugs.
Gear control is carried out by means of a lever located in the cab. The principle of operation of the circuit is a remote drive located above the power unit. In the bracket of the cover of the crankcase of the transmitting unit, a pair of support rollers is provided, which serve to switch speeds using grooves and necks placed on the adjusting rods.
In the middle position, the lever is located with a pin with a lock and a spring up. At this time, the lower analogue of the fuse is activated along with the spring. The pin is externally mounted in the oscillating compartment of the first and reverse gears. The leash is mounted on a pivot pin mounted in front of the box lid.
Other details
The MAZ semi-trailer in the system is equipped with a front roller that controls the second lever inserted into the head of the movable rod of the bracket. The outer part of the movable rod is connected to the intermediate control mechanism using a cardan elongated rod. The fixing bracket is attached to the vehicle frame.
The lower edge of the shift lever is connected to the same node. Mounting method - similar to the above method. Part of the arm goes through the cabin floor, ensuring the integrity of all other connections. This design makes it possible to tilt the cab without the need for separation and deformation of existing elements and assemblies.
In conclusion
I would like to dwell in more detail on the features of the gearbox of the MA3-2G0 machine. This block is almost identical to the device on the Drive gear does not have a damper, but the second, third and fifth speeds are switched on using the secondary shaft on needle-type bearings. The switching lever is located on a ball bearing, the body of which is fixed on the cover of the switching box. It has a reverse activation fuse, as well as a pin with a spring installed in the steering bracket socket. The node in question proved to be excellent as a direct competitor of domestic and foreign analogues, in accordance with the combination of price and quality parameters.
One of the famous brands of Belarus is MAZ. The produced equipment from the Minsk Automobile Plant (MAZ), which includes tractors, timber trucks, heavy vehicles, is known throughout the world.
Components of the checkpoint MAZ
The vehicle gearbox (MAZ) includes several gears that are connected to the gear lever. Each of the available gears performs its function, rotates at a certain speed, providing efficient control of the machine.
The manufacturer placed the box in the MAZ car between the crankshaft and cardan shaft. The crankshaft is a component part characterized by a complex shape. High demands were placed on the production of this element. The cardan shaft is no less reliable working mechanism, the function of which is to transfer the moment of force between the shafts.
Gearbox drive
In addition to the shafts, the MAZ manual gearbox includes a crankcase, mortar, synchronizers. The speed control on the machine is carried out by changing gears. Interacting with each other, the gears are able to both increase and decrease the speed of the MAZ. The lever with the gear divider works effectively.
MAZ checkpoint scheme
The MAZ gearbox air distributor is designed to switch air flows. The device is located in the top cover of the crankcase.
The MAZ transfer case is a complex mechanism that provides wheel locking and affects gear changes.
Given this, the MAZ transfer case is installed on heavy vehicles that are great for operation on a dirt road, poorly equipped tracks.
The MAZ gearbox with a demultiplier includes an intermediate shaft drive gear, which is equipped with a damper. The damper helps to reduce vibrations. The MAZ pillow helps to suppress noise from the checkpoint while driving.
Scheme of the demultiplier
Gearbox options for heavy vehicles
The 8-speed MAZ gearbox is typical for vehicles that have a high carrying capacity.
9-speed versions are installed not only on powerful trucks, but also on ordinary cars.
5-speed gearboxes are present on the MAZ-500 car with the YaMZ-236 diesel engine.
5 speed gearbox
16-speed versions are found on dump trucks, KamAZ vehicles. The mass of the box in this case exceeds 250 kg. The ZF16S gearbox has an adapter plate that communicates with the engine and gearbox.
The listed versions are distinguished by high reliability, long-term working capacity.
A MAZ car with a ZF gearbox is decided to be purchased by those who want to enjoy a full ride both in urban conditions and on rough terrain. Often this type of gearbox is found on snowplows.
The need for checkpoint maintenance
Contributes to the extension of the resource of the speed box - its timely maintenance. In particular, the car owner must monitor the efficiency of the gears, the control lever, and control the level of oil poured into the MAZ automobile system.
If it is necessary to repair the gearbox at MAZ, it is necessary to dismantle the gearbox from its regular place. The device should be visually inspected for external deformations. It is highly likely that this is the reason that the checkpoint "does not obey" the driver's commands. If there are no deformations, you can proceed to the analysis into the components of the gearbox.
If the MAZ checkpoint circuit fails, then the following symptoms will appear:
- some gears do not work, for example, 4 and 5;
- manual switching is difficult.
To flush the gearbox, about 3 liters of special oil are required. Repair of the MAZ gearbox may consist in the restoration of bridges, washing, fault detection of the box. Also, the crankcase and cover are subject to repair.
2381-3902150 IE
Gearboxes
YaMZ-2381
YaMZ-238VM
YaMZ-238VK
YaMZ-238VU
and their modifications
User manual
This manual applies to KP YaMZ-2381; YaMZ-238VM; YaMZ-238VK; YaMZ-238VU; YaMZ-238VL of all modifications and establishes the basic requirements for the operation of gearboxes.
1 Characteristics
The YaMZ-2381 gearbox is eight-speed mechanical, consists of a main four-speed gearbox and a two-range planetary demultiplier.
Gearboxes YaMZ-238VM; YaMZ-238VK; YaMZ-238VU; YaMZ-238VL differ from the above gearbox in the input shaft, input shaft cover and oil pump.
Gearboxes YaMZ-238VM4 (238VK4; 238VU; 238VU2; 238VU4; 238VL) are designed for installation together with a double-plate clutch of the YaMZ-238 type and a cardan shaft with a “smooth” flange.
YaMZ-238VM5 gearboxes (238VK5; 238VU1; 238VU3; 238VU5; 238VL1; 2381; 2381-30) are designed for installation together with a YaMZ-183 type diaphragm clutch and a cardan shaft with a “smooth” flange.
Gearboxes YaMZ-238VM7 (238VM1; 238VK7; 238VU6; 238VU7; 238VU9; 238VL1; 2381-02; 2381-05; 2381-31; 2381-52) are designed to be installed together with a YaMZ-183 type diaphragm clutch and cardan shaft with " euro” flange.
Gearboxes YaMZ-238VM4; YaMZ-238VM5; YaMZ-238VM7 can be installed instead of discontinued YaMZ-238A gearboxes; YaMZ-238A3; YaMZ-238A5 in accordance with the recommendations (see Appendix).
1.1 Gear shifting is carried out in accordance with
with picture 1.
Figure 1-Scheme of the positions of the gear lever.
Attention!
When controlling the gearbox using a mechanical remote drive, the positions of the gear lever handle may differ from those shown in the diagram and are indicated in the vehicle's operating manual.
When moving the shift lever from neutral to reverse, resistance should be felt from the spring mechanism. Engage reverse gear only after the vehicle has come to a complete stop.
1.1.1 Range switch mechanism
equipped with an automatic low range lockout system (ASBP). The ASPB relay is designed in such a way that it allows the inclusion of the lower range at a speed of rotation of the gearbox output shaft of not more than 920 rpm, which corresponds to a vehicle speed of 25-35 km/h.
1.2 Gear ratios of the gearbox are given in table 1
Table 1
Broadcast |
Transfer in the main box |
range in demultiplier |
Gear ratio |
1234 |
1234 |
lower |
7,304,863,502,40 |
5678 |
1234 |
higher |
2,091,391,000,71 |
s.h. |
s.h. |
lowerhigher |
10,462,99 |
2 Operation of gearboxes.
Change gears from first to fourth and from fifth to eighth by moving the shift lever to the appropriate position.
To turn on the fifth gear, leave the fourth gear engaged and move the range switch button to the higher range (the location of the range controls is indicated in the vehicle manual).
Fifth gear is engaged by moving the shift lever of the main box to the first gear position. At the moment of transition through the neutral position, the highest range in the demultiplier is automatically switched on; at the same time, hold the lever in the neutral position until the range switch switching lamp goes out.
To switch from fifth to fourth gear, switch the range switch button to low range when fifth gear is engaged, while the vehicle speed should not exceed 35 km / h. Then shift the gearshift lever to the neutral position, hold until the indicator lamp goes out and turn on the fourth gear in the main box.
Starting off a loaded car from a place to produce in first gear. Starting the car in second gear is allowed only on paved roads with a partial load of the car.
Reverse movement should be carried out only when the lower range is turned on in the demultiplier.
3 Maintenance.
3.1 Gearbox lubrication
The following oils should be used to lubricate the gearbox:
all-weather gear oil TSp-15k GOST 23652-79
(SAE 85W-90);
all-weather gear oil MT-16p GOST 6360-83 (substitute);
all-weather gear oil TAD-17I GOST 23652-79 (SAE 85W-90);
“YAR. Mark T” TU 0253-019-00219158-95 (SAE 80W-90; GL-3);
Angrol TSp-15k TMZ-18 GOST 23652-79 (SAE 85W-90; GL-3);
a mixture of oil TSp-15k GOST 23652-79 (85%) and diesel fuel grade A or Z GOST 305-82 (15%) (for operation at temperatures below minus 30°C);
grease Litol 24 GOST 21150-87 (for lubricating parts of the clutch release mechanism);
grease No. 158 TU 38.101.320-77 (for lubricating parts of the demultiplier switching mechanism).
Filling capacity of the lubrication system from 7.5 to 8 liters. The oil level below the control hole located on the right side of the spacer is not allowed.
3.2 Maintenance after running the car.
After running in the car, change the oil in the gearbox housing, clean the oil intake grid and the drain plug magnet from the run-in products.
3.3 First maintenance (TO-1).
3.3.1 Check the oil level in the crankcase and top up if necessary in accordance with this manual.
3.4 Second maintenance (TO-2).
3.4.1. Perform all first maintenance operations.
3.4.2. Fill the clutch release clutch with grease, making 3-4 strokes with a syringe.
3.4.3 Lubricate the clutch release fork roller through two grease fittings, making 2 strokes with a syringe.
3.4.4 Check and, if necessary, adjust the rear gearbox support in accordance with the vehicle operation manual.
3.5 Additionally, through one TO-2.
3.5.1 Change the oil in the gearbox with flushing the crankcase, mesh and magnet.
3.5.2 In the absence of a regulated vehicle maintenance system, change the oil depending on the operating conditions according to the following scheme:
cars with an annual mileage of 80,000 km. and more after 50,000 km.
vehicles with an annual mileage of less than 80,000 km. and under severe operating conditions (dirt road, mountainous or hot desert terrain, etc.) - after 30,000-40,000 km.
Attention!
When using a substitute oil, the timing of its change should be halved. Drain the gearbox oil immediately after hot work. Crankcase flushing should be carried out with liquid industrial oils (I-12A or I-20A according to GOST 20799-88). It is forbidden to flush the gearbox with diesel fuel or kerosene, in order to avoid failure of the oil pump.
3.5.3 Clean and lubricate the gearbox air distributor parts (using grease No. 158 according to TU 38.101.320-77; Litol-24 grease can be used according to GOST 21150-87).
3.5.4 Clean and lubricate the piston and the working surface of the switch cylinder of the demultiplier with grease Litol-24 GOST 21150-87.
4 Rules for towing a car.
Towing a car with an idle engine can only be done with the cardan shaft disconnected.
Attention!
Towing the car in violation of the above rules leads to the failure of the gearbox.
5. Possible transmission malfunctions.
5.1. Possible malfunctions of the gearbox and methods for their elimination are given in table 2.
table 2
Possible malfunctions |
Elimination Methods |
||
Difficulty shifting gears |
|||
incomplete clutch disengagement (clutch “leads”)wear or damage to the synchronizer, teeth of gear couplings are damaged |
adjust pedal free playif the defect is due to defective clutch parts, replace the damaged partsreplace the faulty synchronizer, replace damaged parts |
||
Increased noise during gearbox operation |
|||
not enough oil in the gearboxgear shaft bearing wearincreased wear or chipped teeth |
fill with oil up to the level of the control holereplace worn gears |
||
Spontaneous disengagement of gears when the car is moving |
|||
uneven wear of gear couplingsmalfunctions of rods and forks of the gear shift mechanismincreased wear of gearbox bearings |
replace defective partsreplace defective partsreplace defective bearings |
||
Spontaneous disengagement of gears in the demultiplier |
|||
the flow of compressed air into the cylinder cavity opposite to the engaged gearrange fork bearing wear |
replace the defective O-rings of the spool and the inlet valve of the air distributorreplace worn parts, adjust the position of the range cylinder rod |
||
Non-engagement or delayed engagement of gears in the demultiplier with the lever in the neutral position in the main box. The alarm lamp does not go out for a long time, air exits through the air distributor breather |
|||
wear of the sealing ring of the inlet valve of the air distributoruneven fit of the intake valve to the bodyintake valve sticking in the depressed positionjamming of the edge of the cuff in the piston groove, wear or loss of elasticity of the cuffs |
replace worn outvalvereplace sealing ringreplace defective partsclean and lubricate intake valve stem, polish if necessaryto replace cuffs of the cylinder of switching of a demultiplier |
||
Non-engagement or slow shifting of gears in the demultiplier with the lever in the neutral position in the main box. The alarm lamp does not go out for a long time, air exits through the breather of the top cover. |
|||
damage to the air diffuser membranewear or loss of elasticity of the O-rings of the range shifting cylinder rod |
replace damaged membranereplace damaged rings |
||
Passing air through the air distributor breather with the gear engaged in the main box |
|||
wear of the rubber of the inlet valve of the air distributorloose fit of the pusher to the inlet valve in the air distributor |
replace valvereplace defective parts |
||
6 Features of the assembly of the gearbox.
6.1 Before installing the demultiplier with a spacer on the crankcase of the main box and the spacer on the crankcase of the demultiplier, apply anaerobic sealant UG-6 TU 6-01-1285-84 on both sides with a continuous strip 2-3 mm wide. along the contour.
6.2 When installing the demultiplier with a spacer on the crankcase of the main box (Figure 2) and the cover of the output shaft of the demultiplier (Figure 3), ensure minimum axial play of the shafts using shims selected as follows:
-measure dimension A with an accuracy of 0.1 mm. from the end face of the outer ring of the bearing of the surface of the crankcase of the main box (Figure 2) or the crankcase of the demultiplier (Figure 3) with the bearing pressed to the stop.
-measure dimension B with an accuracy of 0.1 mm. the depth of the groove for the bearing in the gear coupling (Figure 2) or the output shaft bearing cap (Figure 3), taking into account the thickness of the gasket.
- select the total thickness of the shims, which should be less than the difference B-A by 0.15 ... 0.2 mm
6.3. When installing the input shaft bearing cover (Figure 4), ensure the minimum axial play of the shaft using shims selected as follows:
-measure dimension B with an accuracy of 0.1 mm. the depth of the groove for the bearing in the bearing cap, taking into account the thickness of the gasket
-measure dimension A with an accuracy of 0.1 mm. from the end face of the outer ring of the bearing to the surface of the crankcase wall with a pressed bearing
- select the total thickness of the shims, which should be less than the difference B-A by 0.2-0.3 mm.
6.4. Tighten the nuts for fastening the crankcase of the multiplier in two steps (see table 3). Tightening sequence according to figure 5.
6.5 When repairing the demultiplier with the replacement of synchronizer parts, adjust the required rod stroke when the upper range is turned on, ensuring unloading of the fork bearings, for which:
6.5.1 turn on the highest range in the demultiplier with the adjusting bolt turned out, by supplying air under pressure from 784 to 833 kPa (8 ... 8.5 kgf / cm2) into the pneumatic cylinder. Verify that the high range clutch teeth are fully engaged. When fully engaged, the indicator lamp should go out, the driveshaft mounting flange should not turn by hand.
6.5.2 Screw the adjusting bolt into the piston rod until it stops (when turning the bolt, a noticeable increase in resistance to rotation should be felt) Repeat the operation several times, making sure that the stop is felt at the same position of the bolt head.
6.5.3 Turn the adjusting bolt from the position of its stop to the end by 5…7 faces of the bolt head (5/6…7/6 turns) and, holding it in this position, lock it with a lock nut, tightening it with a torque from 137.29 to 156, 9 Nm (from 14 to 16 kgf/m). After adjustment, the driveshaft mounting flange should turn easily, without jamming by hand. Rotate the flange through an angle of at least 360°.
Attention!
Incorrect adjustment causes an unacceptable overload of the range fork bearings, which leads to their rapid destruction.
7 Tightening torques for the main threaded connections.
7.1 The tightening torques of the main threaded connections are given in table 3.
Table 3
Table 3. Name of fasteners |
Tightening torque Nm (kgcm) |
Bolts of fastening of a crankcase of coupling to a crankcase of a box |
137-157 (14-16) |
Bolts for fastening the clutch housing to the flywheel housing |
70-80 (7-8) |
Bolts for fastening the spacer to the crankcase of the main box |
123-157 (12,5-16) |
Bolts of fastening of a crankcase of a demultiplicator to a spacerpreload
|
20-30 (2-3)79-98 (8-10) |
Bolts of fastening of the top cover of a crankcase of the main box |
35-49 (3,6-5) |
Axes of a fork of switching of a range |
118-128 (12-13) |
Bolts of fastening of a cover of a primary shaft |
23,5-35 (2,4-3,6) |
Low range gear coupling to spacer bolts |
23,5-35 (2,4-3,6) |
Bolt of fastening of a flange of an output shaft |
363-422 (37-43) |
8 Preparing the gearbox for operation.
8.1 Before installation, the gearbox must be depreserved in accordance with clause 11.3. this manual.
8.2 The bolts securing the gearbox to the engine and the cardan shaft to the gearbox must be securely tightened.
8.3 The gearbox rear support must be adjusted in accordance with the vehicle's operating instructions.
8.4 After mounting on the vehicle, the gearbox must be connected to the pneumatic and electrical systems of the vehicle (see figures 7 and 8).
9 Completeness.
9.1 A longitudinal section of the gearbox is shown in Figure 6.
9.2 The gearbox is delivered fully assembled on a wooden stand with transport parts that protect the gearbox from mechanical damage, dirt and precipitation.
Attention!
To prevent breakage of the contacts of the switch of the range switching signaling lamp, the switch is turned out and tied to the pneumatic pipelines of the gearbox in the package, and the threaded hole is closed with a plug. Before installation, remove the plug and screw in the switch.
10 Transportation and storage.
10.1 Gearboxes can be transported by any mode of transport. The gearbox mounting must ensure its safety from damage during transportation; a protective cover must be installed on the cardan shaft mounting flange.
10.2 Gearboxes must be stored in closed, dry rooms. Acids, alkalis and other chemicals must not be stored in these rooms (storage conditions “C”
GOST 15150-69).
11 Preservation and re-preservation.
11.1 Gearboxes are shipped to the consumer with short-term conservation, ensuring the safety of gearboxes for three months from the date of shipment from the manufacturer, subject to the requirements of clause 10.2.
11.2 At the request of the consumer, gearboxes can be subjected to long-term conservation according to the manufacturer's technology, which provides storage for 36 months. Information about long-term conservation is entered in the “Conservation Act”.
11.3 When depreserving gearboxes, remove the protective casing, paraffin paper, unscrew the drain plug, drain the remaining preservation grease, screw the plug.
Conservation act
Preservation and packaging done
Date______________200
Preservation period up to _______________
12 Acceptance certificate
Transmission___________________
(model)
Serial number ___________________ is manufactured in accordance with the current technical documentation and recognized as fit for use.
OTK stamp _______________________
_________________ _______________________
(personal signature) (signature transcript)
________________
(year, month, days)
13 Warranty.
13.1 The Tutaev Motor Plant guarantees the correct operation of the gearbox subject to the requirements of the “Instructions for the operation of YaMZ-238B engines; YaMZ-238D; YaMZ-238N; YaMZ-238L; YaMZ-238FM” and this manual
13.2 The gearbox must be installed on the vehicle no later than three months from the date of shipment from the manufacturer's factory. Gearboxes that have undergone conservation must be installed on the vehicle no later than the period specified in the Conservation Act.
13.3 The warranty period is 12 months from the date of installation of the gearbox on the vehicle. The warranty mileage for this period should not exceed the value established by the instructions for a specific modification of the car.
Application
Recommendation for the installation of gearboxes of the YaMZ-238VM type instead of gearboxes of the YaMZ 238A type.
This recommendation applies to YaMZ-238VM4 gearboxes; YaMZ-238VM5; YaMZ-238VM7 of all modifications and establishes the basic requirements for the installation of these gearboxes instead of YaMZ-238A gearboxes; YaMZ-238A3; YaMZ-238A5.
1 General information
The YaMZ-238VM4 gearbox is installed instead of the YaMZ-238A gearbox.
The YaMZ-238VM5 gearbox is installed instead of the YaMZ-238A3 gearbox.
The YaMZ-238VM7 gearbox is installed instead of the YaMZ-238A5 gearbox.
2 Preparing for installation
2.1 Purchase the required gearbox YaMZ-238VM-1700003-40 (50 or 70).
2.2 Purchase relay 6312.3747 (manufacturer, Kaluga).
2.3 Purchase cardan shaft (see table 1).
Table 1
Table 1 Modelcar |
Modelboxesgear |
Designationcardan shaft |
Note |
MAZ-5432 and modifications |
YaMZ-238VM4YaMZ-238VM5 |
5551-2201010-02 |
2 X axletractor 4x2 |
YaMZ-238VM7 |
5551-2201010-10 |
||
MAZ-5516 and modifications |
YaMZ-238VM4YaMZ-238VM5 |
5516-2205010-20 |
3 X axledump truck 4x4 |
YaMZ-238VM7 |
54328-2201010-10 |
||
MAZ-6422 and modifications |
YaMZ-238VM4YaMZ-238VM5 |
64229-2205010-01 |
3 X axletractor 6x4 |
YaMZ-238VM7 |
64229-2205010-10 |
Attention!
For cardan shaft numbers not listed in this table, for other car models, check with the car manufacturer or service centers.
2.4 Release the gearbox from the technological stand by removing the transport plug from the propeller shaft mounting flange, the protective cover of the demultiplier switch indicator switch and the packing paper from the input shaft, remove the plug from the top cover.
2.5 External inspection should make sure the integrity of the speed sensor and air supply pipes.
2.6 Install the demultiplier switching indicator switch (the switch is packed in paper and tied to pipelines), having previously removed the metal transport plug.
2.7 Lubricate the spline part of the input shaft with a thin layer of Litol-24 GOST 21150-87 grease and make sure that the clutch release bearing is filled with the specified grease.
3. Mounting and dismantling.
3.1 To remove the YaMZ-238A gearbox from the car, you should:
- remove the landing gear;
- dismantle the cardan shaft by disconnecting it from the gearbox and drive axle;
- disconnect the air supply pipe from the pressure reducing valve;
- disconnect from the air distributor the air supply pipelines from the pneumatic control valve of the demultiplier;
- disconnect the plug of the clutch release booster valve from the clutch release lever;
- disconnect the air supply pipe from the clutch release cylinder;
- disconnect the electrical wires from the switch of the signal lamp for switching the demultiplier, the switch for the reverse signal lamps and the speedometer drive sensor;
- having unscrewed the four fastening nuts, disconnect the gear shift mechanism together with the control rod or shift lever from the gearbox and take it aside;
- having unscrewed the nuts, remove the rear supporting support of the power unit;
- unscrew the bolts of the bracket with fuel pipes from the gearbox cover;
- unscrew the bolts and remove the brackets of the supporting support of the power unit;
- bring a lifting mechanism under the gearbox;
- unscrew the bolts securing the clutch housing from the flywheel housing, hang out the gearbox and disconnect it from the engine;
- lower the gearbox onto the trolley, raise the rear of the car and roll out the trolley with the gearbox from under the car, then lower the car.
3.2 Before installation, rearrange from the YaMZ-238A gearbox to the YaMZ-238VM gearbox:
-clutch release lever;
- the bracket together with the clutch release cylinder;
- the switch of signal lights of a backing and a ball of Ø14 mm.;
- speedometer drive sensor and replaceable sensor drive gears.
3.3 To install the YaMZ-238VM gearbox on a car, you must:
- raise the rear of the car and roll the trolley with the gearbox under it, then lower the car;
- hang out the gearbox with a lifting mechanism and, avoiding large distortions, attach it to the engine, aligning the splines of the input shaft and the clutch discs;
- tighten the bolts securing the clutch housing to the flywheel housing with a torque of 7 ... 8 kgm, disconnect the lifting mechanism;
- fix the bracket with fuel pipes on the gearbox cover with bolts;
-install the standard rear supporting support on the gearbox bracket;
- place the cross member with the plate downwards over the supporting support on the spars (see Figure 9);
Attention!
The drawings of the cross member were developed in relation to the MAZ-54323 car, before manufacturing the cross member for other car models, it is necessary to measure the distance between the frame side members in the plane of the gearbox support and, if necessary, change the corresponding dimensions of the cross member.
-measure the distance “A” between the cross member and the supporting support (see figure 10);
- select a package of adjusting plates (see Figure 11) of thickness “A”, install it between the cross member and the supporting support and fix the supporting support on the cross member with bolts;
-drill a 13 mm hole in place (coaxially with the holes in the cross member) in the flanges of the side member;
- fix the cross member with bolts;
- fix, by wrapping four nuts, the gear shift mechanism, aligning the shift lever with the groove on the heads of the rods;
- connect the electrical wires to the switch of the signal lamp for switching the demultiplier, the switch of the reverse signal lamps, the speedometer drive sensor;
- connect the air supply pipelines from the demultiplier control valve to the air distributor and the solenoid valve (see Figure 7);
- connect the air supply pipe from the pneumatic system of the car to the air distributor;
- connect the valve plug of the clutch release booster to the clutch release lever;
- connect the air supply pipeline to the clutch release cylinder;
-Install cardan shaft;
- fix the landing gear in place;
- install the relay in the driver's cab in a convenient place;
- connect the relay to the electrical system of the gearbox and the car (see Figure 8);
Attention!
The gearbox is operational in the absence of a relay. However, switching the demultiplier at vehicle speeds above 25 ... 30 km / h will lead to its rapid failure.
The manufacturer's warranty does not apply to a gearbox operated without a relay!
4. Adjustment.
After carrying out the installation work, in accordance with the vehicle operating instructions, adjust:
The ability to drive is not only turning the steering wheel when maneuvering and alternating pressing the accelerator and brake pedals, it is also the right choice of the gear engagement position in the transmission shift box. Of course, CVTs and other types of automatic and semi-automatic gearboxes have been developed a long time ago, where the torque variability is selected by the node “independently, following the preset settings. They just have some limited “choice”, and they are rare on SUVs and trucks. Why, and why are they needed at all? We answer ...
How does the switch work
Different coverage or variations of its absence, changing the relief along the “up-down” vector, moving empty, with an average or full load - each of the proposed cases requires a specific speed of rotation of the propulsion wheels and the effort with which it all happens. The internal combustion engine has certain limits in terms of the numerical expression of frequency and torque, to expand it, and to be able to stably hold it in several positions, the gearbox is designed.
At the same time, automatic transmissions also have clearly defined reactions, and the work of a heavy truck is often associated with the ability to quickly, sometimes even unexpectedly vary the speed-torque of the drive shafts. Especially if you have to go on a road, the condition of which is far from ideal. And since the manual transmission is controlled remotely, by means of a lever-switch, it must also know which of its positions correspond to which moment-speed.
Of course, it would be possible to do something like a linear displacement, but in this case the rocker mechanism would resemble a thick rocker in dimensions, and it is possible that it would become cramped in the cockpit. And this is even with a standard 4-speed, 5-speed, but we won’t talk about 9, 12 and 16-speed transmissions. Therefore, designers have to “cram” all the possibilities into a complex, but compact drawing-diagram. And it is necessary to remember it because the mismatch of the selected transmission-range is not only a problem with overcoming the route, but the risk of increased wear of parts, especially if the “irregularities” are systematic.
HOW TO SWITCH
The standard version - control scheme for example, is present on the 500th MAZs. For those who are able to forget in what order everything happens, a pattern is applied on the handles of the main working tool for changing the speed-transmission. It looks like this:
- - freely walking on the horizontal average vector handle - "neutral";
- - left-up - first, -down - reverse;
- - center-down - the second, -up - the third;
- - to the right-up - the fourth, -down - the fifth.
In a checkpoint with demultiplier dividers, the pattern either remains and the upper and lower ranges overlap when the additional box is previously initiated, or the pattern itself becomes more complicated, receiving a couple of additional “branches”.
The transfer of "commands" from the handle-lever through the transverse roller is transmitted to the industrial mechanism, from there through the main thrust to the industrial lever. Then a special axial roller “turns on” and sets the gearbox shift lever itself in motion.
For such a "workhorse" as the MAZ-500 and its modifications, due to the loads experienced, problems with even the correct change in transmission speed are not uncommon. There are plenty of possible malfunctions due to which the MAZ gearbox circuit does not work as provided, but the most common are three options.
1. Do not "catch" the first and rear during the normal functioning of the rest.
To eliminate such a nuisance, you need to mark the position of the rod to its tip, loosen the coupling bolts and turn the tip clockwise by about 4-5 degrees (about 1 mm between the marks). Then the bolts are tightened and the functionality is checked. If the problem persists further, then repeat the operation, that is, move the tip a little more.
2. When the rest are working, the 4th and 5th do not work.
We do everything the same as in the previous case, but this time the tip must be turned counterclockwise.
3. The system itself works normally, but switching is hampered by the wrong position of the lever (for example, the lever rests against the panel).
We expose the neutral and disconnect the tip of the thrust from the earring of the switching mechanism. We make sure that the lever of the mechanism is also in the neutral position - the fork is located vertically, and with angular swaying, resistance to rotation is felt. If everything is so, then we wrap the locking screw on the intermediate mechanism until it stops, thereby fixing the intermediate roller "tightly". We loosen the coupling bolts and set the rod along the length so that the stopper finger easily passes through the holes of the earring and tip. We connect them and tighten the coupling bolts. After that, we unscrew the locking screw of the industrial mechanism by five turns, and lock it with a nut.
By the way, after partial disassembly of the drive, its adjustment is carried out according to the same principle.
Finally, we remind you that you can find and buy most of the components for drives, mechanisms and boxes (also transfer cases and all kinds of additional gearboxes) in the online store of our SpetsMash trading house. We work wholesale and retail, opal - cash and bank transfer, delays are expected. We organize delivery in Russia (to many cities for free), communication by phone, E-mail and through the company's website.
Switching scheme
1 236-1702060-А2 1st gear and reverse shift fork rod
2 236-1702014 Cover gasket
3 236-1702015-B2 Upper cover
4 236-1702129 1st gear and reverse fuse
5 236-1702127-A Fuse spring
6 236-1702132 Spring cup
7 236-1702087 Fork rod lock pin
8 316172-P29 Stopper
9 200-1702083 ball
10 236-1702122 Lever support gasket
11 216258-P29 Stud
12 252136-P2 Spring washer 10
12 252136-P2 Spring washer 10
13 250513-P29 Nut
14 236-1702126 Driver axle
15 236-1702125 Leash for shifting 1st gear and reverse
16 252137-P2 Spring washer
17 250615-P29 Nut
18 236-1702170-A Breather
19 262522-P2 Stopper
20 236-1702025 Set screw
20 236-1702025 Set screw
21 236-1702225-B Gear lever
22 260311-P15 Plug
23 260310-P15 Plug
23 260310-P15 Plug
23 260310-P15 Plug
24 236-1702213 Bushing
25 236-1702129 1st gear and reverse fuse
26 236-1702106 Spring
26 236-1702106 Spring
26 236-1702106 Spring
27 236-1702215 Bolt
28 236-1702209-B3 Carter
29 236-1702206-B3 Carter for remote gear change mechanism, assy
30 236-1702235 Retainer spring cup
31 252161-P2 Washer
32 236-1702100 Locking ball
33 236-1702229-A Fork rod head
34 312534-P2 Lock washer
35 310213-P29 Bolt
36 201499-P29 Bolt 10-6gx30
37 316121-P29 Plug K 1/4"
38 236-1702216 Sealing ring
39 236-1702227 Rod fork longitudinal thrust gear shift
40 236-1702024 Fork shift 1st gear and reverse
41 236-1702221 Roller
42 314040-P2 Key
43 236-1702222 Gear lever
44 236-1702241 Gasket
45 236-1702240 Crankcase cover for remote gear change mechanism
46 252135-P2 Spring washer
47 201454-P29 Bolt M8x16
48 236-1702027 Shift fork 2nd and 3rd gear
49 236-1702053 1st gear and reverse shift fork rod head
50 236-1702028 2nd and 3rd shift fork rod head
51 236-1702033 Switch fork 4th and 5th gear
52 236-1702064 2nd and 3rd shift fork rod
53 236-1702074 4th and 5th shift fork rod
Link to this page: http://www..php?typeauto=6&mark=14&model=46&group=82
