5.13. The back bridge

Fig. 5.11. The back bridge: 1 – a decorative cap; 2 – a hairpin of fastening of a brake drum and a wheel; 3 – маслоотражатель the semiaxis bearing; 4 – a brake drum; 5 – a pig-iron ring of a drum; 6 – the working cylinder of a back brake; 7 – the union for prorolling of brakes; 8 – the semiaxis bearing; 9 – запорное a bearing ring; 10 – a flange of a beam of the back bridge; 11 – an epiploon; 12 – a cup of a spring of a suspension bracket; 13 – a beam of the back bridge; 14 – an arm of fastening of the top longitudinal bar of a back suspension bracket; 15 – directing to a semiaxis; 16 – an adjusting nut of the bearing of differential; 17 – the bearing of a box of differential; 18 – a bearing cover; 19 – сапун; 20 – the satellite; 21 – a conducted gear wheel of the main transfer; 22 – полуось; 23 – a semiaxis gear wheel; 24 – картер a reducer The back bridge; 25 – an adjusting ring; 26 – распорная the plug of bearings; 27 – bearings of a leading gear wheel; 28 – an epiploon of a leading gear wheel; 29 – грязеотражатель; 30 – a flange; 31 – маслоотражатель; 32 – a leading gear wheel of the main transfer; 33 – an axis of satellites; 34 – a basic washer of a gear wheel of a semiaxis; 35 – a differential box; 36 – an arm of fastening of details of a suspension bracket; 37 – a plate of fastening of the bearing of a semiaxis; 38 – the holder of bolts of fastening of a plate; 39 – a board of the back bridge; 40 – колодка a back brake; 41 – an overlay brake pad

13 (fig. 5.11) the back bridge is attached to a beam картер a reducer 24 in which the main transfer and differential are located. Conducting 32 and conducted 21 gear wheels of the main transfer are picked up in pair for a stain of contact and noise, therefore at damage of one of them both are replaced. Between internal rings of bearings 27 leading gear wheels the plug 26 which, being deformed at a tightening of a nut of a leading gear wheel is located распорная, provides a preliminary tightness in its bearings. Between an end face of a leading gear wheel and the internal bearing the adjusting ring 25 defining correct position of a leading gear wheel concerning the conducted is established.

The conducted gear wheel of the main transfer is attached to a flange of a box of 35 differentials which rotates on two bearings 17. A preliminary tightness in these bearings, and also a backlash between teeths of leading and conducted gear wheels regulate the nuts wrapped in demountable beds of bearings. Semiaxial gear wheels 23 are established in cylindrical nests of a box of differential and lean against a box through basic washers 34. Selection of washers for a thickness establish a lateral backlash of 0-0,1 mm between teeths of satellites and semiaxial gear wheels.

Полуось 22 internal end enters in шлицевое an aperture of a semiaxial gear wheel, and external leans against the ball bearing 8 which is fixed on a semiaxis запорным by a ring 9. The semiaxis bearing is condensed in a beam nest from the inside самоподжимным by an epiploon 11, and outside – the rubber ring clamped between a board of 39 brakes and a flange of a beam of the back bridge. The bearing is fixed in a nest of a beam by a plate 37 which together with маслоотражателем 3 and a board is attached by bolts to a beam flange.

Tightness of consolidations check external examination. To check more conveniently from below the car established on the lift or a viewing ditch. Places in which it is possible подтекание oils are more low listed.

1. Stoppers drain 1 and bulk 2 apertures.

THE NOTE At подтекании oils from under stoppers of apertures tighten them.

2. A socket on a reducer flange.

THE NOTE «Потение» round places possible подтекания it is admissible. Formation of drops is not supposed.

GOOD ADVICE At подтекании oils from under a reducer flange tighten bolts of fastening of a reducer to картеру the back bridge. At подтекании oils from under any bolt of fastening of a reducer which is not eliminated by a bolt tightening, establish a washer from soft metal (aluminium) under a head of a bolt or apply a thin film hermetic on a carving part of a bolt.

3. An epiploon of a leading gear wheel.	4. If the semiaxis epiploon flows here has failed.

5. Podtekanie oils from consolidations can cause littered сапун («the Back bridge», «Features of a design» see). If traces подтекания oils are found out, clear сапун of a dirt, check up freedom of moving of a cover сапуна in all directions, carefully wipe places подтекания and after run of 20-30 km again them examine. If traces подтекания are found out again, probably, сапун is littered and in картере the back bridge at its heating in an operating time the pressure which is squeezing out oil from consolidations raises. Turn out сапун and clean. If and after cleaning it is observed подтекание oils from consolidations, replace сапун as, probably, it is faulty (заедает the valve). If and at serviceable сапуне oil all the same leaks from consolidations, replace consolidations.

According to the service book in a reducer of the back bridge it is necessary to replace oil through each 45 000 km of run.

It be required to you: a key «on 17», шестигранник «on 12», a syringe for refuelling of units of transmission, capacity for the fulfilled oil.

GOOD ADVICE This operation is more convenient for carrying out on a viewing ditch or on the lift. It is recommended to merge oil right after trips while the back bridge has not cooled down also oil possesses good fluidity.

1. Turn away a drain stopper and...	2.... Merge oil.

3. Turn and tighten a drain stopper.

4. Turn away a jellied stopper.	5. Fill in fresh oil by means of a syringe to level of the bottom edge of a jellied aperture.

6. Turn and tighten a jellied stopper.

Полуось in gathering with the bearing replace at raised in comparison with usual noise from outside back wheels of the car both at movement on a straight line, and on turns. Are thus observed raised axial and radial люфты semiaxes.

THE NOTE The axial backlash no more than 0,7 mm is supposed.

GOOD ADVICE Editing of a semiaxis and replacement of its bearing are labour-consuming and demand the special equipment. Therefore we recommend at occurrence axial or radial люфтов semiaxes to replace полуось in gathering.

It be required to you: a key «on 17», a key for nuts of wheels, an inertial stripper.

1. Remove a wheel and a brake drum (Removal and installation of a brake drum »see«).

2. Turn away four nuts of bolts of a plate of fastening of the bearing of a semiaxis.	3. Establish a support and raise the back bridge.

4. Remove an arm of the shock-absorber from bolts of a plate of fastening of the bearing of a semiaxis.	5. Remove полуось by means of an inertial stripper.

GOOD ADVICE In the absence of a stripper establish on полуось a wheel and fix its three nuts, without tightening them it is definitive so that between a wheel and a semiaxis there was a backlash. Press a wheel to a semiaxis and then sharply pull a wheel on itself. In most cases after several attempts полуось it is possible to remove.

THE PREVENTION If you are not going to change an epiploon, be careful – do not damage its working edge.

6. Fix the brake mechanism by means of a wire.	7. Examine полуось; if it погнута or has cracks, replace it.

8. Estimate a condition шлицевого connections; if шлицы are crumpled or worn strongly out, replace полуось.	9. Check up the condition of a sealing ring crumpled or the torn ring replace.

10. Establish полуось and the removed details in an order, the return to removal, paying special attention on correctness of an arrangement of a sealing ring.

It be required to you: a key for nuts of wheels, a hammer.

1. Remove a wheel and a brake drum (Removal and installation of a brake drum »see«).

2. Screw a nut on a replaced hairpin заподлицо with its end face.	3. By means of a hammer...

4.... Beat out a hairpin and...	5.... Take it from a semiaxis aperture.

6. Establish a new hairpin in gathering with the prorate of suitable diameter (it is possible to use the big nut) and a nut.

7. Tighten a nut to...	8.... Full прилегания hairpin heads to a flange plane.

9. Turn away a nut and remove the plug.

10. Establish a wheel.

Epiploon replace new at detection of a leak of oil («Check of tightness of consolidations of the back bridge» see).

It be required to you: a key «on 17», a key for nuts of wheels, a screw-driver, an inertial stripper, a hammer.

1. Remove полуось (Removal and semiaxis installation »see«).

2. Take an epiploon by means of a screw-driver from a nest crankcase the back bridge.	3. Establish a new epiploon and it is accurate запрессуйте with the help send suitable diameter and a hammer.

GOOD ADVICE In quality send it is possible to use an old epiploon.

4. Establish полуось and all removed details in an order, the return to removal.

Epiploon replace new at detection of a leak of oil («Check of tightness of consolidations of the back bridge» see).

It be required to you: keys «on 13», «on 24», a screw-driver, динамометрический a key, a hammer.

THE NOTE Necessity of replacement of an epiploon is defined by volume of leak of oil. Before check of volume of leak check up freedom of moving of a cover сапуна in all directions to be convinced that сапун is not at the bottom of oil leak. Check up oil level in картере the bridge and finish to norm if necessary. Do not forget to wrap a stopper маслоналивного an aperture. If you work on a viewing ditch, will hang out the back bridge and put it on support. Start up the engine, include direct (IV) transfer and at the established indication of a speedometer of 90-100 km/h allow to the bridge to work not less than 15 mines for oil warming up (the oil temperature should be 80–90 °С). By the included direct transfer and the indication of a speedometer of 100 km/h define quantity of following oil. If for 15 mines follows more than 5 drops of oil, the epiploon is subject to replacement. Before epiploon replacement switch off transfer and muffle the engine

.

1. Lower down to an emphasis the lever of a lay brake (if the car has been braked by a lay brake).

2. Merge oil from crankcase the back bridge (oil Replacement in the back bridge »see«). Do not forget to wrap a stopper маслосливного an aperture.

3. Remove both semiaxes (Removal and semiaxis installation »see«).

4. Disconnect back propeller a shaft from a flange of a leading gear wheel of a reducer of the back bridge (Removal and installation карданной transfers »see«).

5. Check up динамометрическим a key the resistance moment проворачиванию a leading gear wheel. Remember its value.	6. Turn away a nut of fastening of a flange of a leading gear wheel.

7. Remove the flat washer established under a nut and...	8.... Remove a flange of a leading gear wheel.

9. Take an epiploon of a leading gear wheel from a mouth crankcase a reducer by means of a screw-driver.	10. Grease working surfaces of a new epiploon with greasing Litol-24, and an external surface – a thin layer of hermetic.

11. Establish an epiploon into place and easy blows of a hammer through the mandrel запрессуйте it in картер a reducer on depth of 1,7-2,0 mm from a mouth end face crankcase a reducer.

12. Establish a flange of a leading gear wheel, then a washer.

13. Establish and tighten a nut of fastening of a flange. The moment of an inhaling of a nut should be 117–254 Н·м (12–26 кгс·м) depending on the resistance moment проворачиванию a leading gear wheel. At a nut tightening begin with the smaller moment and periodically check the resistance moment проворачиванию a leading gear wheel (see operation 5). If the initial moment of resistance was 58,8 Н·см (6 кгс·см) and above the inhaling moment should be on 9,8–19,6 Н·см (1–2 кгс·см) more initial. If the initial moment of resistance was less than 58,8 Н·см (6 кгс·см) a nut of fastening of a flange tighten before reception of the necessary moment of resistance 58,8–88,2 Н·см (6–9 кгс·см).

THE PREVENTION If as a result of a tightening of a nut of fastening of a flange нормированным the moment (12–16 кгс·м) you find out that the resistance moment проворачиванию a leading gear wheel will be exceeded, it testifies to inadmissible deformation распорной the plug established between bearings. It is necessary to replace the plug. Such replacement is connected with dismantling of a reducer and the subsequent adjustment of gearing of gear wheels of the main transfer. This work demands high qualification and application of special adaptations. It is not recommended to spend her independently – address in the specialised workshop having the corresponding equipment.

14. Establish the removed details in an order, the return to removal.

Before reducer replacement be convinced of necessity of its replacement, having executed check in road conditions.

Check spend on country highway in the absence of heavy traffic of transport with observance of necessary safety measures.

1. Move with a speed about 20 km/h. Define and remember characteristic noise at movement. Then gradually increase speed to 90 km/h in a mode of acceleration habitual for you. Simultaneously listen to various noise and notice speed at which they appear and disappear.

2. Release a management pedal throttle заслонками and, without using brakes, will reduce speed braking by the engine. During delay watch noise change, and also behind intervals at which noise is shown more. Usually noise arises and disappears at the same speeds both at acceleration, and at delay.

3. Disperse the car approximately to 100 km/h, put the gear change lever in neutral position, switch off ignition and allow to the car to slide freely to a stop.

THE PREVENTION At ignition deenergizing be cautious. Turn a key only before position "is switched off". Otherwise can work the antijoy ride device, the steering mechanism will appear locked and the car becomes uncontrollable. Also consider that at the idle engine efficiency of brake system (owing to switching-off of the vacuum amplifier) and a steering (if by the car the hydraulic amplifier is established) decreases.

4. The noise noticed during this test and corresponding noticed at test 1 (operations 1 and 2), does not proceed from a reducer. The reducer without loading cannot be a noise source, except for the noise caused by bearings.

5. The noise noted at test 1 (operations 1 and 2) and not repeating at test 2 (operation 3), can proceed from a reducer, semiaxes or bearings. Continue check.

6. At the motionless and braked car start up the engine and, gradually increasing frequency of rotation of a cranked shaft, compare the noticed noise to noise of two previous tests. The noise noticed at this test which correspond to noise of the first (operation 1 and 2) tests, do not concern a reducer. They can be caused in other knots and car units.

7. Will hang out back wheels, establish the car on support. Start up the engine and include IV transfer. Note noise at engine work on various frequency of rotation of a cranked shaft.

8. The noise which have been found out at the first test (operation 1 and 2) and not repeated at the subsequent, proceed from a reducer.

Reducer of the back bridge remove for replacement or repair. However dismantling, adjustment and assemblage of a reducer demand use of the special equipment and assume presence of skills at the executor. Reducer repair in garage conditions practically never leads to desirable result. Therefore in case of need reducer repair take advantage of services of a specialised workshop.

It be required to you: keys «on 12», «on 13», a screw-driver, an assembly shovel, динамометрический a key.

GOOD ADVICE Replace a reducer on the lift or a viewing ditch.

1. Merge oil from crankcase the back bridge.

2. Remove both semiaxes (Removal and semiaxis installation »see«).

3. Disconnect back propeller a shaft from a reducer of the back bridge (Removal and installation карданной transfers »see«).

4. Turn away eight bolts of fastening of a reducer to a beam of the back bridge and...	5.... Remove a reducer.

6. Examine interfaced surfaces crankcase the back bridge and a reducer.

THE NOTE On a part of cars картер it is condensed by a lining. At removal or replacement of a reducer it is subject to replacement. If the reducer is established without a lining (by means of hermetic) it is necessary to give particular attention at a hermetic choice. He should answer severe conditions of work of the given knot of the car.

7. Establish a new reducer in an order, the return to removal.

GOOD ADVICE If you establish a reducer after repair or adjustment, remove a small emery paper the rests of an old lining and the hardened hermetic from a flange. Put hermetic on bolts of fastening of a reducer

.

THE NOTE Bolts of fastening of a reducer tighten in regular intervals and gradually cross-wise the moment 35–43,5 Н·м (3,6–4,4 кгс·м).

THE PREVENTION Do not forget to fill in oil in картер the back bridge.

The back bridge remove for its replacement at a wear-out of all details when partial repair becomes inexpedient, or for beam replacement at its damage.

It be required to you: a key for nuts of wheels, keys «on 10», «on 12», «on 13», «on 14», «on 15», «on 17», «on 19», шестигранный a key «on 12», the big screw-driver or an assembly shovel, пассатижи, a jack.

1. Establish the car on a viewing ditch or the lift.

2. Establish the lever of a lay brake in the bottom position.

3. Ослабьте wheel nuts of back wheels, raise a back part of the car, turn away wheel nuts and remove back wheels.

4 Merge oil from crankcase the back bridge (oil Replacement in the back bridge »see«).

5. Disconnect a back cable of a lay brake from directing and...	6.... Take out a cover of a cable from two arms on the body bottom («Replacement of a back cable of a lay brake» see).

7. Disconnect a flange back карданного a shaft from a flange of a leading gear wheel of a reducer of the back bridge (Removal and installation карданной transfers »see«).

8. Turn away a nut of a bolt of fastening of a rack of the lever of a drive of a regulator of pressure and disconnect a rack from an arm of the back bridge.	9. Disconnect hoses of brake system from pipelines of the back bridge («Replacement of hoses» see).

THE PREVENTION Take measures for prevention of leak of a brake liquid, having muffled an aperture of a hose make-shifts (for example, a wooden stopper).

10. Substitute under a beam of the bridge of a support and lower on them the car, slightly having loaded a suspension bracket.	11. Disconnect the bottom ends of shock-absorbers («Replacement of the shock-absorber of a back suspension bracket» see).

12. Remove springs of a back suspension bracket («Replacement of a spring of a back suspension bracket» see).	13. Turn away a nut of a bolt of fastening of the left top longitudinal bar to a bridge beam, take out a bolt and disconnect a bar from a bridge beam (Removal and installation of longitudinal bars of a back suspension bracket »see«).

14. Similarly disconnect the bottom longitudinal bar and the right longitudinal bars from a bridge beam (Removal and installation of longitudinal bars of a back suspension bracket »see«).

15. Turn away a nut of a bolt of fastening of a cross-section bar to a bridge beam, remove a bolt and disconnect a bar from a bridge beam (Removal and installation of a cross-section bar »see«).

16. Fix a bar, having fixed it, for example a wire, to the lever of a drive of a regulator of pressure.

17. Lift the car. The back bridge remains on support.

18. Establish the new back bridge in an order, the return to removal. Do not forget to pump over a hydrodrive of brakes and to fill in oil in картер the back bridge.

The back bridge can be disassembled completely directly on the car. However, if replacement crankcase the bridge is required, work is more convenient for carrying out on the removed bridge (Removal and installation of the back bridge »see«).

It be required to you: keys «on 8», «on 10», «on 12», «on 13», «on 17», heads face «on 12», «on 17», the extension piece, вороток, a screw-driver, a key for nuts of brake tubes, a key for stoppers of drain apertures, capacity for oil plum.

1. Establish the car on a viewing ditch or the lift.

2. Establish the lever of a lay brake in the bottom position.

3. Ослабьте wheel nuts of back wheels, raise a back part of the car, turn away wheel nuts and remove back wheels.

4. Merge oil from crankcase the back bridge (oil Replacement in the back bridge »see«).

5. Remove brake drums (Removal and installation of a brake drum »see«).

6. Remove semiaxes (Removal and semiaxis installation »see«).

7. Turn away bolts of fastening of a tip of a cover to a brake board.	8. By means of a screw-driver disconnect a tip of a cable of a lay brake from разжимного the lever.

9. Turn away a nut and disconnect from working cylinders brake pipelines.	10. Muffle apertures of pipelines to exclude вытекание a brake liquid from a hydrodrive of brakes.

11. Remove the brake mechanism in gathering.

12. Disconnect back propeller a shaft from a flange of a leading gear wheel of a reducer of the back bridge (Removal and installation карданной transfers »see«).

13. Remove a reducer of the back bridge (Removal and installation of a reducer of the back bridge »see«).

14. Clear привалочные surfaces of flanges crankcase the back bridge and a reducer of the lining rests.

15. Clear internal surfaces of a beam and crankcase a reducer, and also other knots and details of the back bridge of a dust, a dirt and oils.

16. Collect the back bridge in sequence, return dismantling. Working surfaces of epiploons before installation of semiaxes grease трансмиссионным with oil.