4.4.7. Reducer


Fig. 4-63. Reducer of the back bridge assembled: 1 — the leading gear wheel; 2 — the conducted gear wheel; 3 — the satellite; 4 — a half shaft gear wheel; 5 — an axis of satellites; 6 — a differential box; 7 — bolts of fastening of a cover of the bearing of a box of differential; 8 — a differential box bearing cover; 9 — a plate lock; 10 — an adjusting nut of the bearing; 11 — a reducer case

The reducer of the back bridge is assembled shown in fig. 4-63.

Definition of malfunctions of a reducer on noise
You carry out search of malfunctions in the following sequence:
Test No. 1. Distinctly to define the nature of noise, conduct the car on the highway with a speed about 20 km/h.
Then gradually increase speed to 90 km/h, listening at the same time to different types of noise and noticing the speed at which they appear and disappear.
Release a pedal of management of a butterfly valve and without snubbing reduce speed the engine.
During delay you monitor noise change, and also behind the moment when noise amplifies. Usually noise arises and disappears at the same speeds both at acceleration, and at delay.
Test No. 2. Accelerate the car approximately to 100 km/h, put the gear shifting lever in neutral position, switch off ignition and give to the car the chance to slide freely to a stop; you watch the nature of noise at various speeds of delay.

PREVENTION
At switching off of ignition be attentive and accurate. Do not turn a key more, than it is necessary. It can lead to operation of the anti-theft device.

The noise noticed during test and corresponding noticed at the first test proceeds not from gear wheels of the main transfer as they without loading cannot give noise.
On the contrary, the noise noted at the first test and which is not repeating at the second can proceed from gear wheels of a reducer or bearings of the leading gear wheel or differential.
Test No. 3. At the motionless and slowed-down car turn on the engine and, increasing gradually its turns, compare the arisen noise with noticed in the previous tests. The noise which were similar to noise of test No. 1 will specify that they are not noise of a reducer at test No. 1 and are caused by other knots.
Test No. 4. The noise found at the first test and which did not repeat at the subsequent proceed from a reducer; for confirmation lift back wheels, start the engine and include the fourth transfer. At the same time it is possible to be convinced that noise really proceed from a reducer, but not from other knots, for example, of a suspension bracket or bodies.

Removal of a reducer
If necessary to remove only one reducer:
— merge oil from a bridge beam;
— having raised a back part of the car, establish it on supports and remove wheels;
— turn off nuts of fastening of a board of a brake to a beam and you will put forward half shafts so that they left a differential box;
— disconnect the driveshaft from a reducer, put a support under a reducer case, turn out bolts of its fastening to a beam of the back bridge and take out a reducer from a beam, without damaging laying.

Installation of a reducer
Before installation of a reducer carefully clear a bridge beam of oil.
Put sealing laying on a privalochny surface, insert a reducer into a beam and fix by bolts. Previously grease a carving of bolts with sealant. Before putting sealant carefully degrease bolts and openings in a beam. Attach the driveshaft to a reducer. Establish half shafts and brake drums.
Establish a wheel with the tire and screw bolts of fastening of a wheel without tightening. Having put both wheels, remove supports and lower the car; then tighten bolts of fastening of wheels a dynamometer key.
Through an oil-filling opening fill a bridge beam with oil, previously having cleared and having screwed a drain magnetic stopper in a beam.

Dismantling of a reducer
Fix a reducer at the stand. Remove lock plates 9 (see fig. 4-63), turn out bolts and uncover differential box bearings, adjusting nuts, and external rings of roller bearings. Mark covers before removal that at assembly to establish on former places.
Take out from a reducer case a differential box together with the conducted gear wheel and internal rings of bearings.
To remove the leading gear wheel and its details:

Fig. 4-64. Otvertyvany самоконтрящейся nuts of the leading gear wheel: 1 — a stopper for fixation of a flange of the leading gear wheel; 2 — a face key; 3 — a flange of the leading gear wheel; 4 — an arm for fastening of a reducer at the stand

— turn a reducer case a mouth (fig. 4-64) up and, holding with a stopper 1 flange of the 3rd leader of a gear wheel, turn off a key the 2nd nut of fastening of a flange;
— remove a flange and take out the leading gear wheel with an adjusting ring, an internal ring of the back bearing and with the expansion plug;
— from a case of a reducer take out an epiploon, a maslootrazhatel and an internal ring of the forward bearing;
— to a vypressuyta external rings of forward and back bearings mandrel of A.70198;

Fig. 4-65. Removal of an internal ring of the back bearing of the leading gear wheel universal stripper of A.40005/1/7: 1 — a universal stripper of A.40005/1/7; 2 — the leading gear wheel; 3 — an internal ring of the bearing; 4 — A.45008 adaptation

— remove the expansion plug from the leading gear wheel and by means of a universal stripper of A.40005/1/7 and a mandrel of A.45008 (fig. 4-65) remove an internal ring of the back roller bearing;
— remove an adjusting ring of the leading gear wheel.
For dismantling of differential:

Fig. 4-66. Removal of an internal ring of the bearing of a box of differential universal stripper of A.40005/1/6: 1 — a universal stripper of A.40005/1/6; 2 — an internal ring of the bearing; 3 — a differential box; 4 — an emphasis of A.45028

— remove internal rings of 2 (fig. 4-66) of roller bearings of a box 3 differentials, using for this purpose a universal stripper of A.40005/1/6 and an emphasis of A.45028;
— turn off nuts of fastening of the conducted gear wheel and beat out an axis of satellites from a box;
— turn gear wheels of half shafts and satellites so that the last were rolled out in differential windows then they can be taken out;
— remove gear wheels of half shafts with basic washers.

Check of technical condition of details of a reducer
Before survey of a detail of a reducer carefully wash out. It will facilitate detection of wear and damage of details.
Check whether is not present on teeths of gear wheels of the main transfer of damages and whether contact spots on working surfaces of teeths are correctly located. At unacceptable wear of a detail replace new; if gearing wrong, find the reason.

       NOTE
In spare parts the conducting and conducted gear wheels are delivered by the set which is picked up for noise and contact therefore at damage of one gear wheel replace both.

Check a condition of openings of satellites and surfaces of their axis; at insignificant damages of a surface grind a fine-grained skin, and at serious damages of a detail replace new.
Check the surfaces of necks of gear wheels of half shafts and their landing openings in a differential box, eliminate damages as well as to the previous operation.
Check surfaces of basic washers of gear wheels of half shafts, even eliminate insignificant damages. When replacing washers new select for thickness.
Examine roller bearings of the leading gear wheel and a box of differential; they have to be without wear, with smooth working surfaces. Replace bearings at the slightest doubt in their working capacity, bad condition of bearings can be the cause of noise and jamming of teeths.
Check whether is not present on a case and on a box of differential of deformations or cracks, if necessary replace them new.

Assembly of a reducer
Reliable functioning of a reducer is ensured by strict observance of below-mentioned receptions on assembly and its adjustment.

Fig. 4-67. Details of a reducer of the back bridge: 1 — a flange of the leading gear wheel; 2 — an epiploon; 3 — a maslootrazhatel; 4 — the forward bearing; 5 — the back bearing; 6 — an adjusting ring of the leading gear wheel; 7 — a basic washer of a gear wheel of a half shaft; 8 — a half shaft gear wheel; 9 — the satellite; 10 — a satellite axis; 11 — the conducted gear wheel; 12 — a differential box; 13 — the differential box bearing; 14 — an adjusting nut; 15 — a bolt of fastening of a lock plate; 16 — a lock plate; 17 — a lock plate; 18 — a bolt of fastening of the conducted gear wheel to a differential box; 19 — the leading gear wheel; 20 — a bolt of fastening of a cover; 21 — a spring washer; 22 — laying; 23 — a bolt of fastening of a reducer to a beam of the back bridge; 24 — a reducer case; 25 — the expansion plug; 26 — a flat washer; 27 — a nut of fastening of a flange of the leading gear wheel

Details of a reducer are shown in fig. 4-67.
Assembly of differential. Oil gearbox and establish through windows in a box of differential of a gear wheel of half shafts with basic washers and satellites. Turn satellites and gear wheels of half shafts so that to combine an axis of rotation of satellites with an opening axis in a box, then insert an axis of satellites.
Check an axial gap of each gear wheel of a half shaft: it has to make 0–0,10 mm, and the moment of resistance to rotation of gear wheels of differential should not exceed 14,7 N · m (1,5 kgfs · м).
At the increased gap which is a sign of wear of details of differential replace basic washers of gear wheels of half shafts with others, bigger thickness. If the specified gap does not manage to be received even at installation of washers of the greatest thickness, replace gear wheels new in view of their excessive wear.
Establish the conducted gear wheel on a differential box.
Mandrel of A.70152 to a napressuyta on a differential box internal rings of roller bearings.
Installation and adjustment of the leading gear wheel. The correct provision of the leading gear wheel which is rather conducted is provided with selection of thickness of the adjusting ring established between a persistent end face of the leading gear wheel and an internal ring of the back bearing.
Select an adjusting ring by means of a mandrel of A.70184 and A.95690 adaptation with the indicator. You perform operations in the following order.

Fig. 4-68. Installation by means of a mandrel of an external ring of the back bearing of the leading gear wheel: 1 — a mandrel of A.70171

Having fixed a reducer case at the stand, press external rings of forward and back bearings of the leading gear wheel in case nests, using for this purpose mandrels: for the forward bearing — A.70185, and for back — A.70171 (fig. 4-68).

Fig. 4-69. Determination of thickness of an adjusting ring of the leading gear wheel: 1 — the indicator; 2 — A.95690 adaptation; 3 — the back bearing of the leading gear wheel; 4 — a mandrel of A.70184

On a mandrel of A.70184 imitating the leading gear wheel establish an internal ring of the back bearing by means of a mandrel of A.70152 and insert a mandrel into a mouth of a case of a reducer (fig. 4-69).
Establish an internal ring of the forward bearing, a flange of the leading gear wheel and, turning a mandrel for the correct installation of rollers of bearings, tighten a nut the moment of 7,8-9,8 N · m (0,8–1 kgfs · м).
Fix A.95690 adaptation at an end face of a mandrel 4 and configure the indicator having divisions of 0,01 mm to the zero provision, having established his leg on the same end face of a mandrel of A.70184. Then move the indicator 1 so that his leg rose on the landing surface of the bearing of a box of differential.

Fig. 4-70. The scheme of removal of measurements for determination of thickness of an adjusting ring of the leading gear wheel: 1 — a mandrel of A.70184; 2 — A.95690 adaptation with the indicator; a1 and a2 – distance from a mandrel end face to necks of bearings of differential

Turning a mandrel 4 with the indicator on the left and to the right, establish it in such situation in which the arrow of the indicator notes the minimum a1 value (fig. 4-70) and write down it. Repeat this operation on the landing surface of the second bearing and define a2 value.
Determine thickness of "S" of an adjusting ring of the leading gear wheel which is an algebraic difference of the sizes "an" and "b":
S = a-b,
where and — an arithmetic average distance from end faces of a mandrel of 1 (fig. 4-70) to necks of bearings of differential
and = (a1 + a2) / 2,

Fig. 4-71. Gear wheels of the main transfer: 1 — the conducted gear wheel; 2 — serial number; 3 — the amendment to the 100-th shares of millimeter to nominal situation; 4 — the leading gear wheel

b — a deviation of the leading gear wheel from the nominal situation transferred to mm. The size of a deviation is marked on the leading gear wheel (fig. 4-71) in the 100-th shares of millimeter with a plus or minus.
When determining thickness of an adjusting ring consider a sign of the size "b" and its unit of measure.
Example. Let's say that the size "and" established by means of the indicator is equal to 2,91 mm (the size "and" always positive), and on the leading gear wheel after serial number the deviation "-14" is put. To receive the size "b" in millimeters, it is necessary to increase the specified size by 0,01 mm.
b =-14 · 0,01 mm =-0,14 mm.
Determine thickness of an adjusting ring for the leading gear wheel in millimeters.
S = a - b = 2,91 mm - (-0,14 mm) =2,91 mm + 0,14 mm = 3,05 mm.
In this case put an adjusting ring 3,05 mm thick.

Fig. 4-72. Installation of an internal ring of the back bearing on the leading gear wheel: 1 — an internal ring of a back roller bearing; 2 — a mandrel of A.70152; 3 — an adjusting ring; 4 — the leading gear wheel

Put on the leading gear wheel an adjusting ring of the necessary thickness and a napressuyta a mandrel of A.70152 (fig. 4-72) the internal ring of the back bearing removed from a mandrel of A.70184. Put on the expansion plug.

PREVENTION
At repair of a reducer of the back bridge it is necessary to install the new expansion plug if the case of a reducer, a gear wheel of the main transfer or bearings of the leading gear wheel were replaced. If the specified details remained the same, then the expansion plug can be used still.

Insert the leading gear wheel into a case of a reducer and establish on it an internal ring of the forward bearing, a maslootrazhatel, an epiploon, a flange of the leading gear wheel and a washer.

PREVENTION
Not to damage an epiploon at a press fitting, it needs to be pressed not against the stop, and on depth of 2-0,3 mm between an end face of a case of a reducer and an external surface of an epiploon.

Screw a nut on the end of a gear wheel and, having stopped a flange of the leading gear wheel, tighten it (about the tightening moment see further).

Adjustment of bearings of the leading gear wheel

Fig. 4-73. Dynamometer 02.7812.9501: 1 — the mobile index; 2 — the index of restriction of torque; 3 — the case; 4 – handle; 5 — a core with the tip inserted into the transitional plug of a nut of fastening of a flange of the leading gear wheel

For restriction of axial shifts of the leading gear wheel under working loadings it is very important to create in its bearings a preliminary tightness in the set limits. The tightness is controlled the dynamometer of 02.7812.9501 (fig. 4-73) measuring the moment of resistance to a provorachivaniye of the leading gear wheel.
Extent of tightening of bearings is defined by the moment of resistance to a provorachivaniye. He has to be 157–198 N · cm (16–20 kgfs · cm) for new bearings and 39,2–58,8 N · cm (4–6 kgfs · cm) for bearings after the run of 30 km and more.
It is necessary to tighten a flange nut the moment of 117-255 N · m (12–26 kgfs · l), periodically checking a dynamometer the moment of resistance of bearings to a provorachivaniye of the leading gear wheel.

Fig. 4-74. Check of a preliminary tightness of bearings of the leading gear wheel: 1 — a dynamometer 02.7812.9501; 2 — a case; 3 — the transitional plug

For check of the moment of resistance put on a dynamometer the transitional plug 3 (fig. 4-74), establish the index 2 (see fig. 4-73) restrictions of the moment for division of a scale, the corresponding 196 N of cm (20 kgfs · to cm), and the handle 4 make several turns clockwise. During a provorachivaniye of the leading gear wheel the mobile index 1 should not pass for the index 2 and has to show not less than 157 N · to cm (16 kgfs · cm).
If the moment of resistance to a provorachivaniye is less than 157 N · of cm (16 kgfs · cm), and for bearings after the run of 30 km and more — 39,2 N · cm (4 kgfs · cm), tighten a nut of a flange of the leading gear wheel (without exceeding the set tightening moment) and check the moment of resistance to a provorachivaniye of the leading gear wheel again.
If the moment of resistance to a provorachivaniye was more than 198 N of cm (20 kgfs · cm), and for the earned extra bearings of 58,8 N · cm (6 kgfs · cm) that indicates the overestimated preliminary tightness of bearings, replace the expansion plug new as it from excessive loading was deformed to the size which is not allowing to carry out adjustment correctly. After replacement of the expansion plug repeat assembly with the corresponding adjustments and checks.

Installation of a box of differential
Install in a case previously collected differential box together with external rings of bearings.

Fig. 4-75. Check of a preliminary tightness of bearings of a box of differential A.95688/R adaptation: 1 — the fastening screw; 2 — a key of A.55085; 3 — the conducted gear wheel; 4 — an adjusting nut; 5 — the intermediate lever; 6 — the fastening screw; 7 — an indicator arm; 8 — the screw of tightening of an arm; 9 — the indicator for check of a preliminary tightness of bearings of a box of differential

Establish two adjusting nuts of 4 (fig. 4-75) so that they adjoined to rings of bearings.
Establish covers of bearings and tighten fastening bolts a dynamometer key.

Preliminary tightness of bearings of a box of differential and adjustment of a side gap in gearing of gear wheels of the main transfer
These operations carry out at the same time by means of A.95688/R adaptation and a key of A.55085.
Fix on a reducer case adaptation (fig. 4-75) by screws 1 and 6, having screwed them in openings under bolts of fastening of lock plates of adjusting nuts.

Fig. 4-76. Check of a side gap in gearing of gear wheels of the main transfer by A.95688/R adaptation: 1 — the screw of tightening of an arm; 2 — the indicator for check of a side gap in gearing of the leader and conducted gear wheels; 3 — the screw of fastening of a core of the indicator; 4 — an indicator arm; 5 — the fastening screw; 6 — the conducted gear wheel

On a guide of adaptation displace an arm 7 before contact of the lever 5 with an external side surface of a cover and tighten the screw 8. Weaken screws 1 and 3 (fig. 4-76), and establish an arm 4 so that the leg of the indicator 2 leaned on the side surface of tooth of the conducted gear wheel at edge of tooth, then tighten screws 1 and 3.
Turning adjusting nuts, previously adjust a side gap between teeths of the leader and conducted gear wheels within 0,08 - 0,13 mm. The gap is checked on the indicator 2 when rocking a gear wheel 6. At the same time bearings should not have a preliminary tightness. Adjusting nuts have to be only in contact with bearings, otherwise correctness of measurement of a preliminary tightness is broken.

Fig. 4-77. The scheme for check of a preliminary tightness of bearings of a box of differential: D — distance between two covers of bearings of differential; 1, 2 — adjusting nuts

Consistently and evenly tighten two adjusting nuts of bearings, at the same time covers of bearings of differential disperse and, therefore, the distance of "D" (fig. 4-77) increases. This divergence notes the indicator 9 (fig. 4-75) which leg is affected by the lever 5. Nuts for adjustment of bearings of a box of differential tighten before increase in distance of "D" (fig. 4-77) by 0,14–0,18 mm.
Having established an exact preliminary tightness of bearings of a box of differential, finally check a side gap in gearing of gear wheels of the main transfer which should not change.
If the gap in gearing of gear wheels is more than 0,08-0,13 mm, then bring closer the conducted gear wheel to the leader or remove if the gap is less. To keep the established preliminary tightness of bearings, move the conducted gear wheel, tightening one of adjusting nuts of bearings and weakening another on the same corner.
For exact performance of this operation you watch the indicator 9 (fig. 4-75) which shows the size of earlier established preliminary tightness of bearings. After tightening of one of nuts the indication of the indicator will change as the divergence of the "D" (fig. 4-77) covers and a preliminary tightness of bearings will increase. Therefore weaken other nut until the arrow of the indicator does not return to initial situation.
After movement of the conducted gear wheel, on the indicator 2 (fig. 4-76) check the size of a side gap. If the gap does not meet standard, repeat adjustment.
Remove A.95688/R adaptation, establish lock plates of adjusting nuts and fix them by bolts with spring washers. In spare parts deliver lock plates of two types: with one or two pads, establish plates depending on the provision of a cut of a nut.
Adjustment and repair of knots of a reducer are carried out at the stand at which it is also possible to test a reducer for noise and to check an arrangement and a form of a spot of contact on working surfaces of teeths, as shown below.

Check of contact of a working surface of teeths of gear wheels of the main transfer
For final check at the stand of quality of gearing of gear wheels of the main transfer:
— install the adjusted reducer on the stand and grease working surfaces of teeths of the conducted gear wheel with a thin layer of a lead oxide;
— start the stand; levers of the stand brake rotation of the established half shafts that under loading on surfaces of teeths of the conducted gear wheel there were traces of contact with teeths of the leading gear wheel;
— change the direction of rotation of the stand and, braking, receive contact traces on other party of teeths of the conducted gear wheel that corresponds to the movement of the car back.

Fig. 3-78. Removal of the air filter. Shooters specified nuts of fastening of the case of the filter to the carburetor

Gearing is considered normal if on both parties of teeths of the conducted gear wheel the spot of contact is evenly located closer to a narrow end face of tooth, occupying two thirds of its length and not coming to top and the basis of tooth, as shown in fig. 3-78 "e".

Fig. 4-78. A contact spot arrangement in gearing of gear wheels of the main transfer: I \party of the forward course; II \party of a backing; and and in — the wrong contact in gearing of gear wheels: remove the leading gear wheel from conducted, having reduced thickness of an adjusting ring; c and d — the wrong contact: move the leading gear wheel by conducted, having increased thickness of an adjusting ring; е – the correct contact in gearing of gear wheels

Cases of the wrong divergence of a spot of contact on the working surface of tooth are specified fig. 4-78 (and, in, with, d).
Dismantling of knot is necessary for adjustment of the correct provision of the leading gear wheel with replacement of a ring.
At assembly repeat all operations on a preliminary tightness of roller bearings of the leading gear wheel, on check of the moment of resistance to a provorachivaniye, on a preliminary tightness of roller bearings of a box of differential and on adjustment of a side gap of gearing
gear wheels of the main transfer.

Replacement of an epiploon of the leading gear wheel
Need of replacement of an epiploon is determined by decrease in level of oil in a case of the back bridge (owing to leak of oil through an epiploon) to the level breaking normal work of a reducer.
Fogging of a mouth of a case and even formation of separate drops in the quantity which is not exceeding the below-specified norm is not a dribble sign.
At a plentiful kaplevydeleniye define a condition of an epiploon for what:
— put the car on the elevator or a viewing ditch;
— clear of dirt сапун, check its state;
— having turned off a control stopper, check oil level in a bridge case; if necessary bring oil level to norm;
— clear a reducer case mouth of traces of oil and wipe dry;
— you will hang out the back bridge and put it on supports;
— start the engine, include direct transfer and at a speed of 90-100 km/h warm up oil up to the temperature of 80-90 °C (approximately within 15 min.);
— by the included direct transfer, at a speed of 100 km/h, define amount of the oil following in 15 min.
The oil leak exceeding 5 drops in 15 min. is a sign of malfunction of an epiploon.
The damaged epiploon can be replaced, without removing a reducer from the car if replacement of other details of a reducer is not required.
Epiploon replacement procedure following:
— merge oil from a case of the back bridge;
— weaken bolts of fastening of back wheels; put an emphasis under forward wheels and you will hang out the back bridge; release the parking brake and install the gear shifting lever in neutral situation;
— remove wheels and brake drums;
— turn off nuts of fastening of a board of a brake to a beam of the bridge and a pusher bring half shafts out of a differential box;
— disconnect the driveshaft from a flange of the leading gear wheel and take a shaft aside;
— check a dynamometer the moment of resistance to a provorachivaniye of the leading gear wheel and remember its size;
— holding a flange with a special key, turn off a nut of fastening of a flange of the leading gear wheel and remove a flange with a washer;
— remove an epiploon of the leading gear wheel;
— grease a working surface of a new epiploon with LITOL-24 lubricant and press it a mandrel in a reducer case on depth of 2-0,3 mm between an end face of a case of a reducer and an external surface of an epiploon.
— establish a flange with a washer on the leading gear wheel and, holding it with a special key, tighten a nut of fastening of a flange, periodically checking a dynamometer the moment of resistance to a provorachivaniye of the leading gear wheel.
If the initial moment of resistance to a provorachivaniye was 58,8 N · cm (6 kgfs · cm) and above, the new moment of resistance to a provorachivaniye has to be on 9,8–19,6 N · cm (1–2 kgfs · cm) more initial. If the initial moment of resistance to a provorachivaniye was less than 58,8 N · cm (6 kgfs · cm), a nut of fastening of a flange tighten before receiving the moment of resistance of 58,8-88,2 N · cm (6–9 kgfs · cm).
If when tightening a nut the moment of resistance to a provorachivaniye is exceeded, then sort a reducer, replace the expansion plug new then collect a reducer and adjust as it is specified in the head "Assembly and adjustment".
You carry out assembly of the back bridge to the sequences, the return dismantling.