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Pulley assembly.

Depending on the design of the transmission, pulleys can be located anywhere on the shaft or attached to its mounting end. Split pulleys are installed anywhere on the shaft and assembled without any difficulty. When tightening the two halves of the pulley with bolts, you need to ensure that the parting planes of the pulley are aligned without distortions, displacements or gaps. The pre-assembled pulley is pushed with a keyway onto the key placed in the groove of the shaft, then the nuts are tightened first at the hub and then at the rim.

One-piece pulleys They are often located at the end of the shaft protruding from the bearings. This end is made conical (Fig. 109, a) or cylindrical (Fig. 109, b), with a prismatic or wedge key. The cylindrical shaft with a parallel key has a shoulder to fix the position of the pulley. A washer is placed on the free end of the shaft end, which is secured with screws screwed into the shaft end. In precise joints, the pulley groove and key are fitted by scraping. The key should be installed with light blows of a copper hammer or using a clamp.

Rice. 109. Techniques for assembling pulleys and checking the mutual parallelism of shafts:

a - at the conical end of the shaft, b - at the cylindrical end of the shaft with a key:

1 - shaft, 2 - key, 3 - locking screw; c - seating of the pulley on the splined shaft, d - checking the mutual parallelism of the shafts with weights, d - checking with a metal ruler, f - checking with a cord: 1 - arrow, 2 - pulley, 3 - weight

Centering pulleys along a cone(see Fig. 109, a) gives a better fit between the hub hole and the shaft journal.

Fitting pulleys on splined shafts(Fig. 109, c) has a great advantage over the method described above: it results in better alignment, greater strength and less wear of the mating points.

After installing the pulleys on the shaft, check for correct fit, which boils down to checking for runout. Runout is the vibration of the outer surface of a part as it rotates around its axis. The magnitude of the runout of any point on the surface of a part is the largest range of vibration of this point during one revolution of the part.

The runout of the pulleys causes rapid wear of the bearings, and in the gears of precision high-speed metal-cutting machines it increases vibrations, which worsens the surface cleanliness of the processed parts.

For normal operation of the belt drive, it is necessary that the middle planes of both pulleys be aligned, which is only possible if the axes of the drive and driven pulleys are mutually parallel (Fig. 109, d, e, f).

Assembling and checking V-belt pulleys is no different from flat-belt pulleys.

Whatever the car, sooner or later it will have to be repaired. If your car, for example, has a deformed crankshaft pulley and you need to remove it, then to do this you will have to put the “iron horse” on the parking brake, then use a jack to lift the front part of the car and place it on special supports so that it does not fly off from a jack.

Continuing the procedure started, remove the front wheel on the right side and remove the crankcase protection, if any. Then you should remove the drive belt, which is usually intended for auxiliary units. Before dismantling it, be sure to put a small mark on the belt that will indicate the direction of its rotation.

The next step is to loosen the bolt that secures the pulley to completely lock it from turning.

It is best to carry out such work with an assistant, since you cannot cope with this problem yourself. Next, ask your assistant to engage the highest gear and at the same time press the brake pedal all the way. In the case of an AT model, loosen one of the torque converter bolts and try to attach the drive disc to the transmission dome using a regular steel strip and several suitable bolts and washers.

When the engine is removed from the car, you need to block the flywheel and drive disk. After this, unscrew the mounting bolt and remove the crankshaft pulley from the axle. After removing the VAZ crankshaft pulley, you must check the condition of the oil seal itself. If it is not working, be sure to replace it.

So, first you need to very carefully install the crankshaft pulley onto the axle. Be sure to ensure that the keyway is seated correctly on the key. Check that the pulley itself is completely seated without damaging the working edges of the oil seal. Then screw in the new bolt along with the washer installed on it.

Next, you should block it from turning using the same method as when removing it. Then you should tighten the fastening bolt, applying the force of the first stage, and pull it to the corners of stages two and three. You need to use a special angle-measuring attachment. Alternatively, you can apply reference marks with paint or a high-quality marker.

After completing the steps, the crankshaft pulley can be considered installed. All that remains is to tighten the drive belt itself, which is used for auxiliary units, while ensuring that its original direction of rotation is observed. Don't forget to install the crankcase protection, and also screw on the front right wheel, which you removed before starting work. Having lowered the car to the ground, that is, having previously removed it from the jack, do not forget to tighten the wheel fastening, applying the required effort. Good luck to you and have a nice and long drive in your car!

Why are special technological holes made in pulleys? In auto repair shops, there is a special device for fixing the shaft, which must be bolted to the pulley and the shaft locked.

If there is no special device for fixing the shaft, which is screwed to the pulley, then you need to install good anti-roll devices under the wheels of the car and put 4th gear on the gearbox.

Or, the third option is to rest a pry bar against the flywheel teeth and fix the crankshaft from turning while unscrewing the pulley nut.

Another option is to insert a pin into the pulley hole, and install a pry bar around the pin and the second stop, as in this figure.

How to unscrew the crankshaft pulley

Depending on the design of the crankshaft, the pulley is attached to it either with a nut or a bolt. On rear-wheel drive vehicles, the pulley is usually secured with a nut.
The engines of some rear-wheel drive cars can be started with a special crank, for which special protrusions are made for engaging the crank. This handle is also called a “crooked wrench,” and the engagement for this wrench is called a ratchet.

The pulley fastening nut is installed with a size of 36 or 38 mm on a wrench. Use a socket wrench. The key is strengthened by welding a long handle or putting on a tube to increase the “shoulder”.

How to unscrew the pulley nut:

Place the car on a pit or overpass.
Apply the hand parking brake.
Turn on 4th gear at the gearbox, put chocks under the wheels.
Do not tap too hard on the edges of the nut.
Throw on a socket wrench, extend it with a pipe and remove the stuck nut.

If the pulley nut does not come off:

Move the gearbox handle to neutral.
Remove the spark plug wires from the spark plugs to prevent the engine from starting.
Place a socket wrench on the nut and extend it with a pipe. Place the wrench in such a way that the pipe rests against the ground or the machine spar on the right side to prevent the pulley from turning clockwise.
We make a couple of short sharp turns of the ignition key to turn on the starter. The starter will begin to rotate the flywheel, the flywheel will rotate the crankshaft, and the pulley will be secured with a key. In this case, the stuck nut usually “comes off” quickly.

The crankshaft pulley on front-wheel drive vehicles is generally secured with a bolt. To remove the crankshaft pulley of a front-wheel drive car, you must proceed in this order:

Raise the front right side of the car with a jack. Place a trestle, stump or a pair of wheels with rims.
Remove the wheel.
Dismantle and remove the air filter with housing.
Remove the protective cover.
Loosen the belt tensioner and remove the alternator belt.
To fix the crankshaft, you need to remove the plug in the clutch housing, then insert a pry bar into the hole and rest it between the flywheel teeth.
Now you need to put on the socket wrench, extend it with a pipe and sharply try to turn it counterclockwise. The main thing is to remove the stuck pulley bolt.

If it is not possible to remove the bolt from its place, then we use the method of unscrewing it with a starter. This method is shown above.

Helpful advice from locksmiths who have seen a lot: use solvent or WD-40, or a similar rust preventative. After spraying it on the thread (if the pulley is secured with a nut), you need to wait 15 minutes, then try to unscrew it. If it’s a bolt, then it’s not easy to apply this product to the threads, although if you spray it around the bolt, it’s possible that liquid will pass through the micro-cracks and decarbonize the joint.

Pulley removal

Unscrewing a fastening bolt or nut is only half the battle. Next you need to pull the pulley out of the shaft. The pulley cannot be removed easily by hand unless its seat is broken. In addition, if the pulley fits tightly onto the shaft, it is also secured against turning by a key.

There are special pullers for removing the pulley from the shaft. There are mechanical and hydraulic pullers.

The design of a mechanical puller is simple. Usually it has three legs, with which you need to hook the pulley itself, and rest the central rod against the shaft. After which, you need to rotate the rod, the legs will straighten and pull the pulley towards you. There are even simpler pullers that you can make yourself.
If there is no removable device for the pulley, then you can use pry bars. If one person is filming, then take turns, moving it a little on each side so that there is no distortion. If there are two, then at the same time, from different sides, the pulley is pressed out from the crankshaft with a sharp movement.

It also happens that when using a puller, the walls of the pulley grooves cannot withstand and break off. Therefore, when using pry bars, they must be engaged as close to the shaft as possible.

Installing the pulley on the crankshaft

In order to reinstall the pulley on the crankshaft of the internal combustion engine, you need to check the seats. If there are burrs or burrs, remove them with an emery stone. If the old pulley easily fits onto the shaft, then such a pulley is not suitable. It should fit tightly and be pressed in with a certain amount of effort. Before installing the pulley, to reduce friction, it must be lubricated with oil or lithol.

Video

This video contains useful tips on how to unscrew the nut securing the pulley to the crankshaft of a car engine.

An option for unscrewing the crankshaft pulley bolt using a poly V-belt.

How to remove the crankshaft pulley on a VAZ (2108, 2109, 21099, 2110, 2111, 2112, 2113, 2114, 2115).

How to remove the crankshaft pulley bolt. Bolted connection.

How to tighten a crankshaft pulley very quickly.

Removes the crankshaft pulley on a Honda car without a special key.

Any modern internal combustion engine has additional equipment: generators, pumps, compressors, cooling system pump. For all these mechanisms to work, it is necessary to transmit torque from the crankshaft to the engine equipment. To achieve this, car manufacturers use belt drives. A pulley or several pulleys are installed on the toe side of the crankshaft (from the front of the engine). The mating pulleys of engine components and assemblies are mounted on the engine block, the rotation of which is ensured by a belt drive. The pulley is attached to the crankshaft using a key connection and secured with a bolt or nut.

Structurally, a pulley is a flat wheel with a special channel on the end surface where the belt is placed. Provided there is sufficient tension, the belt engages the pulley and the belt drive begins to operate. Such pulleys are made of steel, aluminum, cast iron.

Types and features of pulleys

Pulleys differ in the shape of the section and the number of “streams” on it. Let's look at the main pulley models.

Pulley for V-belt. The working surface of such a pulley has the standard shape of a deep groove with flat surfaces, which follows the shape of the belt. Such a pulley can have two or more working streams, that is, several pulleys can be combined into one;
Pulley for poly V-belt. On one flat surface of such a pulley there are several small streams - ribs in a row. This section is repeated on the belt. The efficiency of such gears is higher, since the contact plane of the working surfaces is larger;
Pulley for toothed belt. This pulley has a transverse tooth similar to the teeth of a gear. The belt also has the same cross-section. During operation, the belt teeth engage with the pulley, the transmission operates;
Crankshaft pulley with damper. The torque, say when starting an engine or braking an engine, can increase or decrease sharply. To reduce impulse loads on the crankshaft pulley, pulleys with a damper are used. The operating principle is as follows: a damping insert is provided between the base and the working part of the pulley, the rigidity of which allows the belt drive to operate and compensates for sharp impulses of the crankshaft.

Pulley malfunctions and checking their condition

The pulley and belt drives operate due to the frictional force between the contact surfaces, so a common reason for replacing a pulley is the wear out of the working plane. Due to dynamic loads, the metal of the pulleys cracks and chips.

Another typical problem for such parts is the backlash of the key in the keyway of the crankshaft. The reason for this is wear on the landing planes of the pulley with the shaft. The pulley fastener with such a malfunction gradually unscrews due to vibrations, increasing the play more and more.

Prolonged operation of the crankshaft with a “loose” pulley will lead to wear and tear of the keyway itself and unscrewing of the crankshaft pulley. Next, the entire assembly rotates on the seat, destroying the key joint, the pulley housing and the crankshaft itself. If a crankshaft pulley is torn off on your engine, there is a high probability that the entire crankshaft will need to be replaced.

In order to determine the condition of the crankshaft pulley, you must:

remove the pulley belts, inspect its edges and body for damage, cracks, wear;
shake the pulley; if there is critical play, the assembly must be disassembled and inspected for wear and damage;
Usually, repair instructions contain the dimensions of permissible wear of parts, distances to the nearest engine components. Checking these dimensions will help determine the suitability of the pulleys for further use.

How to remove a crankshaft pulley: replacing the pulley

Replacing the crankshaft pulley is a simple operation. It is enough to study the design features of your engine and prepare everything you need.

Let's look at replacing the crankshaft pulley using the example of a Renault kangoo. To perform such repairs, it is necessary to immobilize the car and place it on jacks.

The car has a transverse engine position; to access the pulley mount, remove the left wheel;
Since the part rotates during operation, it is necessary to fix the pulley. For this we use special clamps. In the case of Renault engines, there is a special hole in the cylinder block (closed with a bolt) into which the BMT Mot retainer is inserted. 1489 in the form of a threaded pin. It secures the crankshaft;
To block engine rotation you must:
1. unscrew the bolt;
2. install the fixing pin.
Then we install the crankshaft in the repair position by turning it clockwise until it stops against the pin;
Loosen and remove the generator belt;
Then we unscrew the pulley fasteners to the shaft toe and remove the pulley itself. Many people have a question: how to unscrew the crankshaft pulley bolt? Due to constant rotation, the bolt thread is greatly tightened, which is why inexperienced car owners believe that the thread direction is left-handed. However, the crankshaft pulley bolt has a regular right-hand thread and unscrews counterclockwise;
We install a new pulley, tightening the pulley bolt must be done while controlling the tightening torque with a torque wrench (0.8 N.m);
Remove the crankshaft clamp, install the plug bolt;
Reassemble dismantled components and parts in the reverse order of disassembly.

Replacing the crankshaft pulley

Someday, every car enthusiast who is accustomed to doing everything with his own hands is faced with the need to dismantle the crankshaft pulley. Most often this is due to the replacement of seals, which over time become old, crack and begin to leak oil. For an experienced motorist, removing the crankshaft pulley is not particularly difficult, however, as online forums show, ordinary motorists who decide to save money often encounter great difficulties here.

This is what the crankshaft pulley looks like

What's stopping you from removing the crankshaft pulley?

The vehicle's owner's manual and repair manual describe the procedure for removing the crankshaft, including removing the pulley, in a nice, concise manner that makes it seem easy to do. But in reality, everything turns out to be not so simple. There are several reasons for this:

The location of the pulley in the engine compartment is inconvenient for work. It is hidden behind the generator and access to it is limited by elements of the body structure. Pulleys come in regular and damper types, which have an additional outer ring with a rubber seal to absorb vibration. To get to the pulley fastening elements, you need to loosen the tension bolts and remove the generator and power steering belts. And even after this, when performing dismantling work, special care should be taken in applying forces so as not to accidentally damage surrounding nearby parts and the paintwork of the body.
When installed at the factory, the crankshaft pulley is clamped with a high-tension bolt or nut to ensure a secure fit. During engine operation, the right-hand mounting thread further strengthens the clamping force. High temperatures and environmental influences aggravate this process over time through oil coking and metal corrosion. As a result, the fastening nut or bolt firmly adheres to the pulley body, and it is not easy to break this bond of metals without knowledge of special methods.
When the crankshaft rotates freely with any wrench. Therefore, before unscrewing the crankshaft pulley, you should resolve the issue of securely fixing its position in order to prevent rotation when unscrewing the nut. In workshops, special devices are used for this, which are bolted to the pulley into the technological holes and create a reliable stop against rotation. In the absence of such devices, this problem can be solved by installing reliable stops under the wheels and setting the 4th speed of the manual transmission. You can also fix the crankshaft flywheel by resting a pry bar against its teeth or holes.

How to unscrew the crankshaft pulley?

Removing the pulley. Unscrew the nut

The pulley can be secured to the end of the crankshaft using a power bolt or nut. The nut is found on most rear-wheel drive cars. It may have special protrusions for engagement with the “crooked starter” handle, the so-called “ratchet”. To remove the nut, workshop technicians use a 36 or 38 socket wrench with a welded long handle and a locking device placed on the pulley. How to unscrew the crankshaft pulley , secured with a nut, at home? To do this you can do the following:

put the car on a “pit” or overpass;
engage 4th gear to prevent the crankshaft from turning when unscrewing the nut;
raise the parking brake handle all the way up to prevent the wheels from turning and the vehicle from moving forward;
tap the edges of the fastening nut with a wooden hammer;
Using a socket wrench that matches the size of the nut and a handle extension in the form of a metal pipe, try to move the nut with a sharp counterclockwise movement from its stuck position.

Video: How to unscrew the nut on the yoke pulley and replace the oil seal

If successful, you can, by changing the position of the key head, gradually unscrew the nut to the end. If this attempt is unsuccessful, then the following method can be used:

put the gear knob in neutral position;
remove the caps from the spark plugs to prevent sparking and engine starting;
place the head of the wrench on the nut and rest the end of the lever against the ground or spar so that the pulley cannot turn to the right;
briefly turn on the ignition to give the crankshaft a rotation impulse. Usually one or two attempts at starting will help the nut come out of place, and then it can be easily unscrewed with a wrench.

On most front-wheel drive cars, the pulley is secured with a bolt. Before removing the crankshaft pulley , tightened with a bolt, the following operations should be performed:

lift the right side of the car from the front and install it on a trestle or stump, remove the wheel;
remove the air filter unit, protective casing, loosen and remove the drive belt of the electric generator, remove all parts that prevent free access to the pulley;
to lock the crankshaft, you need to remove the plug in the clutch housing and insert a pry bar into the hole, resting it against the flywheel teeth;
Having placed the head of the wrench over the bolt, using the lever extension, apply several sharp forces in the direction of left rotation to tear the bolt from its initial position. Most attempts are successful. If that fails, you can try the method given above for unscrewing the nut, briefly running the starter.

You should also keep in mind the experience of the common people, which allows you to reduce the adhesion of the nut and bolt to the pulley. If you lubricate a bolt or nut with vinegar essence, brake fluid or WD type grease in advance, they will unscrew more easily. There is information about where the crankshaft sensor is located and how to check it.

How to remove the crankshaft pulley

After unscrewing the fastening, you need to remove the pulley. It sits tightly on the hub and is secured with a key, so you won’t be able to simply pull it off the shaft by hand. It is best to use a special puller for this, which has two legs that grip the edges of the pulley and a central twisting screw stop that rests against the shaft axis. If you don’t have a puller, you can use pry bars for this, which you need to evenly pry the pulley from opposite sides, applying force in the direction from the shaft.

You should try to choose the point of application of force as close as possible to the shaft. Before removing the crankshaft pulley, you can gently tap it with a wooden hammer to eliminate any possible distortion. Particular care must be taken not to deform the locking key and groove. Reinstallation of the pulley on the shaft should be done after treating the mounting points with grease, so as not to apply great forces leading to misalignment.