Replacing clutch MAZ 555102

Removing and installing the MAZ clutch

The clutch is removed from the car for repairs or when it is replaced with a new one.

remove the gearbox;
Unscrew the bolts securing the clutch housing to the flywheel and remove the pressure disk 22 with housing 19 assembled (Fig. 33). Unscrew the fastening bolts alternately in 2-3 steps;

unscrew the four automatic adjustment bars of the middle disk withdrawal and remove the four split rings with dampers from rod 2;
remove the driven, middle drive 26 and first driven clutch discs.

To install the clutch you need:

install the first driven disk 25 of the clutch with the elongated end of the hub towards the flywheel 24, the damper springs 30 should be on the opposite side;
install the middle drive disk 26 with rods 2;
install the second driven disk 25 with the elongated end of the hub towards the gearbox, the damper springs should also be located towards the gearbox;
install the pressure plate 22 with the casing 19 assembly using eight short bolts, center both driven clutch discs relative to the axis of the crankshaft with the inserted input shaft of the gearbox and finally tighten the bolts;
put the split rings for adjusting the release of the middle disc onto the rods until they stop at the clutch housing;
install the thrust bars for automatically adjusting the withdrawal of the middle pressure plate and secure them with the casing to the flywheel using eight long bolts;
After installing the clutch on the flywheel, you need to make sure that the rings on the rods rest against the housing, ensuring a gap of (1.2 ± 0.1) mm between the rings and thrust washers when the clutch is engaged.

After performing repair work, it is necessary to adjust the free play of the clutch pedal.

Source

How to adjust the clutch on a MAZ

Clutch is a mechanism designed to transmit torque and change gears in a car, as well as briefly disengage the transmission from the engine flywheel. Its operating principle is based on the influence of sliding friction force.

The term “clutch” can be used in different areas, but most often it is used in the automotive service industry. The clutch connects and disconnects the transmission and engine of the vehicle.

The clutch of trucks deserves special attention; it consists of a double-disc device that is installed in the crankcase of the truck. Its main function is to disconnect and connect the engine crankshaft from the transmission system.

MAZ clutch repair - where to start?

Adjusting the MAZ clutch is much more difficult than repairing the element. We will touch on the nuances of adjustment in the following articles. Now let’s study how to replace the MAZ clutch. Before you start repairing a MAZ spare part, we advise you to think about the causes of the breakdown. The MAZ clutch can fail due to the failure of the driven disk, and due to wear of the bearings, springs and seals. As a result, you may notice that the truck:

Makes sudden jerks during winding.
Makes noise when the pedal is pressed and a burning smell.
Has a discrepancy between acceleration and revolution.

Another reason for MAZ clutch failure is that it is very difficult to change gears.

These wear symptoms can be eliminated by adjusting the clutch.

The very first thing we do is check the CCGT.

Press down on the clutch pedal. Pay attention to the PSU rod. If this element has a stroke, that is, it gradually squeezes out the fork with the release - the spare part is in good condition and does not require replacement. MAZ clutch repair has several stages. After checking the PSU, we look at the clutch casing. Ideally, it should not contain any oil leaks. In some cases, the clutch may “slip” due to excess oil. Let's look and eliminate the reasons. If the car, even after removing the oil and checking the PSU, is not working properly, we will repair the clutch further.

MAZ clutch – what you need to know when buying

The MAZ clutch is the most important transmission mechanism of a Belarusian truck and bus, transmitting torque from the engine to the gearbox.

Having problems with your MAZ clutch? Need a new one for replacement and installation?

Which is better and where is it more profitable to buy a MAZ clutch?

If you are faced with one of these questions, take a few minutes to read the article!

High-quality clutch kits installed on the assembly line in Minsk fully comply with the well-known reliability of equipment from the Minsk Automobile Plant. However, any auto part is subject to wear and tear and has its own resource. In order for your truck tractors and dump trucks to continue to work properly, you need to take the purchase of a MAZ release bearing and clutch disc very seriously.

Composition of the MAZ single-plate friction clutch kit

The MAZ clutch assembly is an integral automotive component of a commercial vehicle, the structure of which consists of:

Why is a clutch needed in a manual transmission?

The purpose of this unit is similar for all commercial vehicles, be it MAZ, MAN, KAMAZ, URAL, GAZelle or PAZ. To familiarize yourself with the general functions and characteristics of clutches, follow the links:

Dump trucks, truck tractors and MAZ buses (a little history)

The decision to create the Minsk Automobile Plant (at that time a car assembly plant) dates back to 1944, making it one of the oldest in the CIS countries. From the first truck (timber carrier MAZ-501) to the present day, when a wide range of equipment is produced for almost all types of economic activity, the main principle of design and engineering services is to provide the buyer with high-quality and inexpensive cars.

The MAZ model range includes:

Truck tractors;
Flatbed dump trucks;
Municipal vehicles;
Scrap trucks;
Manipulators;
Garbage trucks;
Truck cranes;
Log carriers;
Farmers;
Combined machines;
Other special equipment on MAZ chassis.

The production of passenger vehicles was established in 1992, and during this time MAZ buses became widely known in many countries around the world. This is facilitated by the creation of special versions that take into account regional characteristics and requirements. In particular, a special bus model for Africa is being mass-produced.

The Minsk Automobile Plant does not rest on its laurels, but looks to the future with confidence, as evidenced by a number of facts:

Fruitful work of the Center for Advanced Development;
Attracting foreign partners to supply MAZ Euro double-disc and single-disc friction leaf clutches to the assembly line;
Creation of joint production facilities on the territory of the Republic with leading Asian and European corporations;
Organizing the production of new models, such as light commercial vehicles (LCVs).

The reputation that has been earned by many generations of automakers who produced MAZ trucks continues to be maintained today. MAZ vehicles are capable of operating both in the desert and in the Far North, quickly transporting cargo along highways and feeling confident in the off-road conditions of Siberia. The quality of heavy commercial vehicles depends on many factors, but it seems that the most significant are: production technology (assembly) and components.

Replacing the MAZ clutch - removing the gearbox

Failure of the element in question is possible due to failure of the clutch disc, basket and bearing (release). Sometimes discs are filled with oil. However, you can understand why the clutch slips, why the clutch is tight, only after disassembling the gearbox.

Therefore, we remove the gearbox and continue repairing the MAZ clutch. I recommend replacing several MAZ spare parts along the way, which, in principle, do not affect clutch failure.

The fact is that in most cases the elements have significant signs of wear, which will lead to breakdown over time. Moreover, if you are repairing a MAZ clutch, it means that the box has not been removed for at least a year.

Therefore, some consumables will actually have to be replaced. Replacing a MAZ clutch most often includes purchasing a new one:

Clutch disc.
Release bearing hose.
Release bearing.
Gearbox input shaft oil seal.
Bearing spring.
Gaskets for oil pump and shaft.

Only after purchasing new parts do I recommend repairing the MAZ clutch.

Replacement of dump truck clutch

First, we raise the body. Don't forget to lock it in this position.

So replacing the MAZ clutch will not harm you. In general, follow basic safety precautions. Then gradually drain the oil from the gearbox. We disconnect such elements as the body lift pump, cardan and tubes.

Repairing the MAZ clutch also requires removing the yoke with the rear support pad, the PGU and its bracket.

Let me emphasize - ALWAYS remove the bracket! Adjusting the MAZ clutch, most often, if the bracket is not removed, can lead to breakage of the release bearing fork and its spring.

After this, inspect the condition of the release bearing and gearbox basket. If you do not find any signs of wear on these elements, adjust the clutch further. Therefore, we remove the basket from the car flywheel. This will give us access to the clutch disc. Let's examine the detail. If we find traces of damage, we repair it or replace the part with a new one. If the disc is in good condition, then replacing the clutch continues.

Adjusting the MAZ clutch may seem like a simple task, but... there are a lot of nuances here. For example, the support bearing of the input shaft. Let me remind you that it is located in the flywheel. With long-term operation of a MAZ dump truck, this element wears out very much. It all starts with the oil seal. As soon as you replace it, the spare part may still leak oil. Therefore, if you need to replace the clutch, change the bearing too - issues with the oil seal will disappear for a couple of years, just as long as you replace the element in time.

MAZ petal clutch | SpetsMash news

If you try to ask a similar question to all sorts of “Google” and “Yandex”, most likely, in response you will receive a bunch of information on your monitor about where to buy, sell, find a hydraulic or friction, single- or double-disc clutch MAZ

, KrAZ or KamAZ, and so on, but you won’t get a straight answer.

There is a feeling that it seems to exist, and is even used everywhere, but no one knows exactly how it works, or does not want to talk. A similar situation could happen if we were talking about some super modern, almost secret development.

Clutch replacement tips

We recommend that you do such a process as adjusting the clutch in a certain sequence.

Look at the clutch disc first. If it is faulty, replace it with a new one. In this case, pay attention to the support bearing. If the element does not require replacement, simply lubricate it with oil and install it.

Carefully inspect the clutch basket. Adjusting the MAZ clutch requires careful checking of the integrity of the clutch petals, the presence of signs of overheating and cracks. Inspect the release bearing. It is best to replace this part immediately. Otherwise, the MAZ clutch adjustment will be repeated at least twice.

The MAZ clutch adjustment is complete. After completing the process, we install the clutch and gearbox on the dump truck. Naturally, we do the assembly in reverse order. But we will clarify some nuances in the assembly of this element.

Adjusting the MAZ clutch requires removing the clutch disc. However, installing it can present several difficulties. So it is necessary to use the input shaft for alignment relative to the bearing and disc basket.

Also, replacing the MAZ clutch, or rather installing the element, can also be done using a plastic input shaft. As a rule, it is cheaper and lighter. Otherwise, replacing the MAZ clutch and assembling the element usually does not cause difficulties.

Inspect your truck as often as possible. If you identify the causes of breakdowns, urgently repair the MAZ clutch. So this element will rarely bother you.

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Source

Design and principles of operation

The design of the coupling mechanism includes such elements as:

flywheel;
hydraulic power steering;
overlays;
a spring device that presses the disk against the flywheel housing;
clutch release fork, clutch release drive;
push-type coupling;
coupling pedal shaft;
pressure disk;
double-disc or single-disc petal device;
release bearing;
protective casing;
transmission drive shaft.

When the driver presses the pedal, the shaft begins to rotate.
A gap forms between the fork and the push-type coupling.
The clutch, together with the bearing, begins to move, causing the bearing to exert pressure on the inner ring of the handle.
The handle moves the pressure plate away from the driven disc.
The spring mechanism is compressed, causing the disk to move towards the flywheel of the power unit.
The splines of the driven disk move to the splines of the gearbox input shaft.

How the repair is carried out

Main malfunctions and ways to eliminate them:

The clutch mechanism is slipping. This may be due to the lack of free play of the pedal, jamming of the piston part, wear of the friction linings. In this case, it is recommended to adjust the free play of the pedal, clean all cylindrical elements and valves with kerosene, and replace damaged linings and cylinders.
The clutch moves or does not disengage completely. Such a malfunction can be caused by an incorrectly adjusted length of the cylinder rod, insufficient air pressure in the pneumatic system, a leak in the piston seal, or failure of the pull-out levers. The rod length should be re-adjusted, the pneumatic system should be inspected and, if necessary, leaks should be eliminated, the cylinders should be flushed, and all damaged and worn parts should be replaced.
The pedal does not return to its original position. It is recommended to adjust the gap between the back cover and the lock ring, replace worn valves, move the spring mechanism holder closer to the rod, eliminate defects in the rods, clean and lubricate the cylindrical elements of the system.

Clutch adjustment

The adjustment should begin by measuring the free play of the clutch pedal. For YaMZ 238 it should be from 34 to 43 mm. The value should be checked using a ruler, after bleeding air from the pneumatic system in advance. So, if something is not right, we proceed to adjustment. However, first make sure that the gap between the end of the rear cover of the valve body and the retaining ring is within the normal range - 3.5+0.2 mm. If necessary, adjust it too.
Next, it is necessary to adjust the gap from the second driven disk to the thrust ring of the retraction arms. (it should be within 64 mm).
Next, we adjust the gap using the thrust ring and the clutch bearing to engage the YaMZ 238 mechanism. Here the values fluctuate within 3.6 mm. Please note that complete absence of this clearance can lead to failure of the thrust bearing and malfunction of the driven disk.

If the measures taken do not help, and the clutch malfunction persists, most likely, adjustment is not a panacea and the mechanism will need to be replaced.

YaMZ 238 clutch diagram

How to replace

Replacing the clutch is carried out in several stages:

How to remove

In order to dismantle the coupling mechanism, you must perform the following steps:

Place the vehicle on a special platform or inspection hole.
Remove the battery.
Remove the air filter element.
Remove the engine splash guards, which are located in the lower and side parts of the power unit compartment.
Remove the front suspension cross member.
Remove the front drive wheels.
Drain the oil fluid.
Disconnect the speed sensor using a screwdriver.
Remove the reverse switch.
Remove the engine harness holder.
Unscrew the mounting bolts and remove the starter housing.
Disconnect the engine mounts from the gearbox bracket.
Move the clutch back.
Remove the input shaft of the mechanism.
Unscrew the mounting bolts from the coupling mechanism housing. The bolts are unscrewed one by one, in 2-3 steps.
Remove the pressure plate along with the casing.

Assembly

Clutch mechanism assembly steps:

Assemble the driven disk. To do this, it is necessary to attach friction linings to a plastic spring device.
Assemble the pressure plate. You need to lubricate the rollers with a special liquid, place them in the hole of the pull handles, insert the lever into the groove that is located on the pressure-type disk, and install the finger. Attach the support forks to the levers and secure them with cotter pins.
Assemble the pressure disk with the casing. This must be done under a press that can compress the springs and screw the bolts into the support forks. A driven type disk is placed under the press, and a pressure disk is placed on top. Heat-insulating washers and the spring mechanisms themselves are installed on special protrusions. Press the casing using a press and tighten the mounting bolts.
Installing discs into the clutch housing.

Procedure for installing the clutch:

Install the driven disc so that the extended end of the hub faces the flywheel.
Install the drive disk element with rods.
Install a second driven disk with the elongated end of the hub pointing towards the gearbox.
Install the pressure plate.
Attach the cut adjusting rings to the structure.
Install the stop bars and secure them with the casing.
Install the clutch mechanism on the flywheel, check the gap between the thrust rings and washers by engaging the clutch mechanism.

How to install disks

Many drivers are interested in how the clutch disc is installed on a MAZ.

In order to install clutch discs, you must:

Disconnect the driveshaft.
Remove the brake drum and pads from the wheels.
Using a wrench, unscrew the fasteners from the axle shafts and pull them out.
Unscrew the screws that adjust the position of the propeller shaft flange and gearbox.
Disconnect the contacts of the sensor wires, which is responsible for turning on the reverse lights.
Using a 12mm wrench, unscrew the mounting screws from the clutch mechanism protective cover.
Remove the casing.
Using a small crowbar, pry the gearbox housing away from the power unit.
Remove the basket from the flywheel.
Secure the flywheel.
Remove damaged disk elements and replace them with new ones. The driven clutch disc should be directed towards the gearbox, and the pressure disc should be placed so that the hub is directed towards the engine.
Reassemble the coupling mechanism by performing all steps in reverse order.

Adjusting single-plate clutch MAZ 5440

The Minsk Automobile Plant produces reliable trucks, among which the Zubrenok is especially popular. It is mobile and has a stable wheelbase, making it easy to work in city conditions. For correct gear shifting and engine operation, a reliable MAZ 4370 clutch is required, which goes through adjustment after replacement or repair.

Varieties and features

There are two types of MAZ car clutch:

petal Sachs with 360 mm discs;
disk with a spring device.

Most often, on modern models, a petal clutch with two discs is installed, consisting of many elements with a base in the form of a flywheel with crankcase equipment and a spring that works on the principle of pressing.

This clutch on the MAZ “Zubrenok” works using a spring, which is pushed away from the body and disk using thermal insulation washers. The pressure element exerts a directed effect on the driven and driving type washers, moving them towards the flywheel. When turned on, the springs fill the gaps formed between the components of the unit.

Due to constant friction, the clutch disc on a MAZ wears out and requires replacement of the unit, followed by adjustment.

Adjustment process

For correct adjustment, you will need special spanner and open-end wrenches, as well as a caliper and a regular ruler. As a result of the work, the clutch disc on the MAZ 4370 should be in the correct position, ensuring correct functioning. The alignment process takes place in several stages:

Setting the correct distance between the elements of the unit. To do this, you need to equalize the main disk withdrawal gap. At the same time, adjust the housing cover and the corresponding nuts.
Setting up the clutch. After removing the crankcase and the hatch cover, changes are made to the main disk waste indicators. Setting the correct parameters of the clutch itself: a) turning off the unit; b) setting the gearbox lever to the neutral position; c) turning the flywheel and unscrewing the lock nut of the screws; d) unscrew all 4 screws until they stop; e) fixing the unscrewed screws with lock nuts; f) measuring the distance between the nut and the end, which should not be higher than 3.3 mm; g) after fixing the value, the fasteners are tightened and the box is assembled to its original position
Checking operation for smoothness and correctness of gear shifting.

Tip: during adjustment, do not forget to lubricate the MAZ clutch release bearing with machine oil. So, you will increase the service life of the unit by reducing the friction of the elements.

A new clutch should be purchased in advance from a reliable supplier to speed up the repair process. Moreover, if you do not know how to carry out the adjustment correctly or there are no instructions for the purchased spare parts, contact a professional car service. The cost of this type of service is low and takes little time.

Service

Maintenance of this mechanism is carried out as follows:

Carry out an external inspection of the pedal and, if necessary, adjust its free play.
Bleed the hydraulic drive.
Carry out diagnostics of the crankcase fastening elements and, if necessary, tighten the nuts.
Carry out an external inspection of the tension spring device, lubricate the bearings and hydraulic coupling.
Check the functionality of the clutch switch and the shaft sleeve.
Inspect the fork and clutch pedal for wear and damage.
Check the operation of the mechanism by changing the gears of the vehicle on the spot and during acceleration.
Eliminate incorrectly set gaps between support rings and washers.
Eliminate leaks in the system and lubricate all cylindrical elements with a special liquid.
Check the gap between the rods and the piston part of the main cylindrical device.

How to make adjustments

Actions when adjusting the MAZ clutch:

Adjust pedal free play. To do this, you need to put your foot on the pedal and squeeze the gas all the way. If necessary, reduce or increase the stroke of this device.
Release the pedal and measure the distance to the lower mark of the coupling mechanism.
The maximum stroke amplitude should not exceed 16 cm.
Tighten all fasteners.
Measure the pedal free play.

After the driver has adjusted the clutch mechanism, it is necessary to adjust the MAZ clutch basket:

Place the transport on a special platform.
Unscrew the mounting bolts that connect the gearbox and the car body.
Remove the gearbox.
Unscrew the screws of the push-type disk and remove it.
Inspect the basket and replace damaged or worn parts.
Adjust the position of the paws.
Using the adjustment handle, set the paws to the positions shown in the MAZ repair manual.
Tighten all mounting screws until they are secure.
Reassemble the mechanism by repeating all steps in reverse order.