Repair of wheels with use of welding, heating or a rikhtovka is inadmissible. Use of the camera for wheels or tires with leaks does not replace their repair. Porosity in aluminum disks of wheels can be eliminated, see the head "Repair of porous aluminum disks of wheels".

In all models bolts of fastening of wheels with a head on 19 mm with a metric carving of M12x1,5 are used: M – metric, 12 – diameter of a carving in millimeters, 1,5 – a carving step in millimeters.

The recommended pressure in tires for each type of the car is calculated for achievement of optimum parameters of the movement, controllability, life cycle of a protector and the bearing ability of the car.

Pressure is measured in cold tires (tires are considered cold after the car was not in the movement more than three hours, or the distance passed by the car, less than one mile) monthly or before each long trip, and has to be brought into accord with the specifications specified in an instruction for tires on inside of a door of the driver.

The gate should be protected from hit of dust or moisture.

Elevated pressure in tires can lead to the following deviations:

– to the rigid movement of the car;

– the lowered controllability;

– to the accelerated wear in the center of a protector;

– to increase in the effort made for a steering wheel;

– to damages and cracks on a rim;

– to ruptures of a cord of the tire;

– to uneven braking;

– to withdrawal of the car aside;

– to emergence of torque on a steering wheel.

Fig. 14.2. Scheme of shift of wheels

In order that tires of forward and back wheels wore out at the same time, and it was possible to change tires in a set, i.e. 4 wheels, it is necessary to pay constantly attention to uniformity of their wear and in due time to rearrange forward and back wheels. Wheels need to be rearranged not on the car diagonal but only in front back and vice versa as they keep the initial direction of rotation (fig. 14.2).

Because of design features radial tires are inclined to the accelerated wear in "a humeral zone", especially on forward wheels. It does regular shift by especially necessary operation.

After shift surely make sure that nuts of fastening of wheels are tightened by the required inhaling moments, and also adjust pressure in tires.

As the gap between the tire and a body of the car for each type of the car is various, use antisliding chains which act from sides and over a protector of the tire of no more certain size. On the Daewoo cars it is recommended to establish chains of antisliding of a class S of SAE.

Such chains are used for reduction of effect of the slipping arising at rotation of a wheel on the sections of the road covered with snow or ice.

Manufacturers of wheel chains release chains of a certain size for each size of tires. Therefore it is necessary to be convinced that chains, optimum for tires on which they will be used are got.

Use of rubber laying for the selection of sagging or a gap appearing at application of chains not optimum for this type of tires is not allowed.

       PREVENTION

It is sometimes difficult to remove a wheel because of hit of alien material or too dense landing between the central opening of a wheel and a nave. When replacing a wheel never create hindrances to other participants of traffic and ensure own safety. Surely turn on the alarm light system on the car and expose a sign of an emergency stop behind the car.

1. Tighten the lever of the parking brake and include the 1st transfer or transfer of a backing on cars with the mechanical transmission or move the selector lever to a P position on cars with the automatic transmission. Weaken nuts of fastening of a wheel on two turns.

2. Lower the car on the earth.

3. Shaking the car here and there as it is possible stronger, using a body weight and/or switching the transmission, sharply and strongly press a brake pedal to weaken landing of disks of wheels on a nave.

4. Lift the car, turn out nuts of fastening and remove a wheel.

Use of impregnating oil cannot be considered an effective remedy for simplification of removal of densely put disks of wheels. However if nevertheless it is used, it is necessary to try that its small amount got only to a zone of the central opening of a disk of a wheel. Do not allow its hit on vertical surfaces between a wheel and the brake drum or a disk as it can lead to single scrolling of a wheel in attempt to touch the car from the place and control loss.

       PREVENTION

Never use heating to weaken dense landing of a disk of a wheel as it reduces an operational cycle of wheels, bolts and bearings. Excessive efforts, such as blows by the hammer, can also lead to breakage of details and are not recommended for application. Only easy percussions are allowed by a hand or the rubber hammer.

Before installation of wheels remove all traces of corrosion on a privalochny surface of a wheel and the brake drum or a disk with scraping and cleaning by means of a wire brush. Installation of wheels without good contact of metals in the place of contact of privalochny surfaces can be the cause of an otvorachivaniye of nuts of fastening of wheels owing to what the wheel can be removed from a nave that will lead to driving loss.

Nuts of fastening of wheels need to be tightened cross-wise the moment of 90 N • m to avoid deformation of a disk of a wheel and damage of the brake drum or a disk.

At removal and installation of tires it is necessary to use the special equipment for replacement of tires. Do not use a hand tool or assembly shovels: it can lead to destruction of a board of the tire or damage of a rim of a disk of a wheel.

The rim in the place of landing of the tire should be cleared of the remains of lubricant, old rubber and a raid of a rust. At the same time apply a wire brush or rough steel cotton wool. Before removal and installation of tires the place of landing should be processed carefully recommended lubricant for tires.

1. Install the tire; via the gate give compressed air before landing it on a rim; never exceed pressure of 275 kPa.

       PREVENTION

In order to avoid serious injuries it is impossible to stand near the pumped-up tire. The rim can burst at excess of safe maximum pressure. It is impossible to exceed pressure of 275 kPa if landing of the tire to a rim does not happen. If at achievement of this size of pressure landing does not happen, lower air from the tire, repeatedly process lubricant the place of landing and again pump up the tire.

Fig. 14.3. Arrangement of an adjusting ring of the tire

2. Install the gate and pump up the tire up to the optimum pressure. Check and be convinced that the adjusting ring of the tire is visible on both sides around flanges of a rim (fig. 14.3).

There is a large amount of materials and ways of repair of tires. Restoration of the radial tire with a steel cord represents quite difficult task. If defect is found after a long time, the tire framework at the long movement with low pressure in the tire can have serious internal damages. If moisture got into a puncture of the tire and reached a metal cord, the rust can weaken it considerably.

Internal defects are most dangerous as they cannot be found outside of the tire. If to operate the repaired tire at full load of the car and with the maximum speed, it can suddenly collapse. Installation of a hose in the tire can be used as temporary solution of a problem as speakers in a wire of a cord can damage as well a hose.

The beating of wheels can be measured by means of the exact indicator of hour type. Measurements can be taken as on a wheel without its removal from the car, and with use of exact base for fastening of a wheel, for example, such, as at the device for balancing of wheels.

Fig. 14.4. Points of installation of a measuring tip of the indicator of hour type at measurement of a beating of wheels: and - the tire is installed on a disk rim; b - the tire is removed from a disk rim

The radial and axial beating has to be measured with internal and from the outer side of flanges of a rim (fig. 14.4). Reliably fix the indicator of hour type and, slowly rotating a wheel, turn it on one turn. Write down the maximum value shown by the indicator. If this value exceeds admissible specifications limits and vibration cannot be reduced by balancing, the wheel needs to be replaced. It is not necessary to pay attention to any jumps of the indicator caused by welded seams, paint spots, notches, etc.

Steel wheels: a radial beating – 0,8 mm; an axial beating – 1,0 mm.

Aluminum wheels: a radial beating – 0,8mm; an axial beating – 0,8 mm.

The spare tire is included in the package at sale of the car.

Gather on the car assembly enterprise of the tire and a wheel by an adjustment method. It means that the part of the tire which is most condensed in radial measurement called by "a high spot" is interfaced to a wheel in the place where it has the smallest radius called by "a low spot".

At first "ledge" is marked yellow paint or a sticky tag on lateral face of the tire.

"Hollow" of a wheel has to settle down in the location of the gate.

Fig. 14.5. Combination of the gate with the tag put on the tire at adjustment of tires and wheels

Before removal of the tire from a wheel it is necessary to put the line on the tire in the location of the gate for the subsequent installation of the tire in the same situation. On branded tires and wheels there is already such marking (fig. 14.5).

There are two types of balancing: static and dynamic.

Fig. 14.6. Static balancing of a wheel: and – a spot of the largest weight; b – wheel axis; with – installation sites of balance weights

Static balancing is a uniform distribution of weight on the radius of a wheel (fig. 14.6). The wheels which are not balanced statically cause the jumping of the car called by "trample of a wheel". It as a result results in uneven wear.

Fig. 14.7. Dynamic balancing of wheels: and – a spot of the largest weight; b – wheel axis; with – installation sites of balance weights

Dynamic balancing is a uniform distribution of weight in relation to the axial line so that at the movement the wheel could not move here and there (fig. 14.7). At the movement on dynamically not balanced wheels there can be a vibration.

       PREVENTION

Deposits of alien materials on internal surfaces of a wheel have to be cleaned. The stones which got stuck in a protector have to be removed in order to avoid traumatizing the operator when balancing, and also for balancing improvement. The tire has to be carefully examined for the purpose of identification of any damages, and then is balanced according to recommendations of manufacturers.

When replacing a standard nut with heavier lock nut it should be established closer to the gate, and the 14-gram balance weight needs to be established from the opposite side on an internal part of a rim.

When replacing tires always establish a lock nut near the gate so that it always appeared from the party, opposite to 14-gram freight. Compensating a heavy lock nut, freight improves balancing of a wheel without its removal.

It is desirable to carry out balancing of a wheel on the electronic balancing device. The device is convenient in work and allows to execute both static, and dynamic balancing. Though with its help it is impossible to modify an imbalance of the brake drum or a disk as it becomes when balancing without removal of a wheel, this shortcoming is compensated by balancing accuracy (within 3,5 g). When balancing the wheel has to lean the central conical opening on the balance weight (but not bolted openings).

If necessary balancing without removal of a wheel allows to eliminate the vibrations arising owing to an imbalance of the brake drum, a disk or a decorative wheel cap.

The forward suspension bracket should not sag freely. At rotation of the leading axis on too big corners there can be an excessive vibration which can become the reason of breakages in consolidations and connections. It is necessary to follow recommendations of manufacturers of the equipment always.

When balancing without removal do not remove the freights established earlier at dynamic balancing with removal of a wheel. If more than 28 g of additional weight are required, it should be distributed between an internal and external flange of a rim.

       PREVENTION

The conducted tires and wheels assembled have to be given to rotation by the car engine. It is necessary to follow restrictions of speed.

At rotation of driving wheels do not exceed speed on a speedometer of 55 km/h. This necessary restriction as the speedometer shows only a half of the actual speed when one wheel rotates, and another is stopped. Excess of a safe limit of speed of rotation can lead to injuries and breakages.

At static balancing when the weight of freights exceeds 85 g, freights have to be distributed as much as possible evenly between internal and external boards of a rim of a wheel.

Fig. 14.8. Installation of wheel freights: 1 – axis of symmetry of a wheel; 2 – landing surface of a rim; 3 – the freight with a clip established by means of the plastic hammer; 4 – freight with a glue substrate

When balancing wheels with aluminum disks the special, covered with nylon freights with a tightening bracket are applied. Their landing to reinforced edge of a board is carried out by means of the hammer with a plastic tip (fig. 14.8).

Also freights with a glue substrate are applied. At installation of such freights it is necessary to execute the following operations.

1. Smooth out an emery paper before emergence of pure aluminum that place on a wheel where freight will be established.

2. Wipe the place of fastening of freight of 50% with water solution of isopropyl alcohol. For this purpose use pure fabric or a tissue.

3. Dry up a surface hot air. The surface of a wheel has to be warm at a touch.

4. Heat a glue substrate to room temperature.

5. Remove a protective film from a glue substrate. Do not touch a glue surface.

6. Apply freight to the place of fastening and pressure him a hand.

7. To provide good gluing of freight, it is necessary to make effort of 70-110 N • m, at the same time to use the roller.

There are two ways of adjustment of tires in which vibration is formed in spite of the fact that they are correctly balanced. In one method the automatic car which loads the tire and cuts off small pieces of rubber from speakers of places on two external rows of protectors is used.

Adjustment by this method usually is constant and if it is made correctly, then does not make considerable impact on the term of operation of a protector of the tire. Centering of tires by means of the car like the grader is not recommended as it considerably reduces the term of operation of a protector and often does not solve a problem.

Other method consists in removal of the tire and its turn on 180 ° on a rim. It is important that it was made on the tire with a wheel assembled which as it is revealed, cause vibration as there is a high probability of vibration in well mounted knots.

1. Remove the tire and a wheel assembled.

2. Define the locations of areas of leaks, having created pressure in the tire about 345 kPa and having shipped the tire and a wheel assembled in a bathtub with water.

3. Note areas of leaks and remove the tire from a wheel.

4. Rub an internal surface in the field of leak by an emery paper with grain of 80 microns and clear it by means of detergent of general purpose.

1. Put a layer of a special sealant 3 mm thick in the field of leak and let's it dry during 12 h.

2. Install the tire on a wheel, pump up it up to the pressure of 345 kPa and check for lack of leaks.

       PREVENTION

In order to avoid serious injuries it is impossible to stand near the pumped-up tire. The rim can burst at excess of safe maximum pressure. It is impossible to exceed pressure of 275 kPa if landing of the tire to a rim does not happen. If at achievement of this size of pressure landing does not happen, lower air from the tire, repeatedly process lubricant the place of landing and again pump up the tire.

3. Adjust pressure in the tire according to technical requirements.

4. Balance the tire and a wheel assembled.

5. Install the tire and a wheel on the car.

6. Tighten nuts of fastening of a wheel the moment of 90 N • m.

The protective transparent or color covering is applied on a surface of cast aluminum wheels. During its removal or violation there are conditions for destruction. Destruction of a covering can result from use of silikonokarbidny fibers on the brushes applied in some automatic washing devices to cleaning of a body and tires. As soon as the covering collapses, destructive influence of the caustic cleaning substances or the salt applied to topping of roads begins. Further the sequence of operations on cleaning of an old covering and drawing a wheel, new on a disk, is given.

1. Note an arrangement of bolted openings on a wheel and the car.

2. Remove the tire and a wheel from the car.

3. Note a location of freights on an external flange of a rim and remove them.

4. Wash up a wheel water solution of any washing substance from within and outside. Remove lubricant and oil with any liquid cleaner.

5. Remove earlier put covering.

6. Follow one of instructions: "Destruction of a covering of a surface of an aluminum disk of a wheel" or "Destruction of a transparent covering on unpainted disks of wheels".

7. Put instead of former freights freights with a nylon covering.

8. Install the tire and a wheel assembled on the car and fix by nuts, having tightened their moment 90 N • m.

Smooth out the places which are subject to coloring, an emery paper (damp or dry) with grain of 400 microns for the best coupling of a transparent covering with a surface.

1. Install a wheel on the machine for boring of brake drums.

2. Process a wheel a persistent block or a brake slip, pressing an abrasive to a surface of a wheel and, slowly moving it from the center to an outer edge and back, also eliminate damages of a surface. Apply an emery paper with grain sizes in the following sequence.

A. To process paper with grain 80 microns.

B. To process paper with grain 150 microns.

C. To process paper with grain 240 microns.

3. Follow the instruction in the head "Drawing a covering".

1. Remove with chemical solution an old covering. Use a small brush of 6,3 mm in size, dipping it into solvent and applying it on perimeter and spokes of a disk of a wheel.

2. Remove a cleaner, following recommendations of the manufacturer.

3. Process a wheel an emery paper with grain of 240 microns, slowly rotating it on the machine for boring of brake drums or having installed on the car and rotating a hand. It will restore a former type of a wheel and will improve sticking of a protective layer.

4. Follow the instruction in the head "Drawing a covering".

       PREVENTION

In order to avoid serious injuries it is impossible to use the engine for rotation of a wheel when cleaning by its emery paper.

1. Clear a surface of pollution.

2. Moisten a wheel in substance of a covering from 1 to 3 min., then wash out in water and dry up compressed air.

3. Dry up a disk during 24 h (or compulsory drying within 30 min. at 140 °C, then cooling within 30 min.).

       PREVENTION

It is necessary to observe the precautionary measures specified in instructions of manufacturers of two-component systems of a covering. The neglect precautions can lead to emergence of inflammatory process in lungs and allergic respiratory reaction.