4.1. Forward suspension bracket

Possible malfunctions of a forward suspension bracket, their reason and ways of elimination
Features of a design
Forward suspension bracket independent, lever and telescopic like McPherson, with damping racks, twisted cylindrical springs, the lower cross levers and the bearing stabilizer of cross stability.
The forward suspension bracket has a negative shoulder of an obkat at which the point of intersection of an axis of turn of a wheel with the plane of the road is located from outer side concerning the center of a spot of contact of the tire with the road. Such design of a suspension bracket in a complex with the diagonal scheme of a separate hydraulic actuator of brakes gives to the car the increased stability when braking on the slippery road.

Fig. 4.1. Forward suspension bracket: 1 – stabilizer bracket; 2 – hinge of the steering mechanism; 3 – rotary fist; 4 – a bolt of fastening are resistant to a rotary fist; 5 – bolt adjusting disorder corner; 6 – the washer is adjusting; 7 – damping rack; 8 – lower spring ring of a protective cover of a rod; 9 – sealant of the top support; 10 – rack bearing; 11 – rod nut; 12 – nut of fastening of the top support; 13 – support cover; 14 – top support of a rod; 15 – top basic cup of a spring; 16 – top spring ring of a protective cover of a rod; 17 – compression buffer; 18 – rack rod; 19 – protective cover of a rod; 20 – spring; 21 – lower basic cup of a spring; 22 – nave; 23 – brake disk; 24 – brake board; 25 – protective cover of the spherical hinge; 26 – spherical hinge; 27 – bar of the stabilizer of cross stability; 28 – lower lever; 29 – plug rubber stabilizer; 30 – rubber-metal hinge of the lower lever; 31 – frame cross-piece; 32 – steering mechanism; 33 – plastic plug of the stabilizer; 34 – stabilizer pillow; Z5 – a basic washer of the stabilizer; 36 – nuts of fastening of adjusting bolts; 37 – the plug is compensatory; 38 – spring ring of a cover


Basic element of a forward suspension bracket is the damping rack of 7 (fig. 4.1) combining functions of a telescopic element of the directing mechanism and the damping element of vertical fluctuations of a wheel concerning a body. On a damping rack the twisted cylindrical spring 20, the buffer of compression 17 and a protective cover of the 19th rod, fixed on the top basic cup 15 with the persistent bearing 10 and a sealant of the 9th support are collected. On the end of a rod the top support 14 is fixed. Load of a car body is transmitted through the persistent bearing and the top support. In a flute at the top end face of a support the spring ring of the 38th cover of the 13th support limiting movement up of an internal part of a support is established. At change of provision of the top support concerning a body the longitudinal tilt angle of an axis of turn changes.
For reduction of hit of dust under a cover of the 19th rod by means of spring rings 8 and 16 its dense landing on the tank of a damping rack and the top basic cup in which channels for pass of air from under a protective cover in podkapotny space are made is provided. Channels for intake of air are executed also in the top support. The damping rack assembled with a spring, a cover, the compression buffer, the top basic cup and the top support fastens to a rotary fist the 3rd lower arm. The top bolt 5 together with eccentric washers 6 at turn around an axis changes a wheel disorder corner.
To the lower part of a rotary fist 3 two bolts the spherical hinge 26 with a cover 25 fastens. The finger of the spherical hinge fastens to the lower lever 28 of a cross-piece.
The cross-piece with levers presents itself a stretcher of a forward part of the car in the form of a shtamposvarny cross-piece of 31 frames to which fasten a bar of the 27th stabilizer of cross stability by means of brackets of 1 and rubber plugs 29, the lower levers 28 with rubber-metal hinges 30 and the rack steering mechanism 32.
The back ends of a bar of the 27th stabilizer through rubber pillows 34 and plastic plugs 33 connect to the lower levers 28.

Definition of technical condition of a suspension bracket on the car
At each maintenance and repair visually check a condition of protective covers of spherical hinges of a suspension bracket and damping racks, spherical and rubber-metal hinges, rubber plugs and pillows.
The side play of the spherical hinge can be found rocking manually of the lower lever in the vertical plane and the hung-out wheel for top and lower speak rapidly around its longitudinal horizontal axis.
At survey reveal leaks of a damping rack, the tease on a working surface of a rod, deformation and damage of other details and knots of a suspension bracket, zadevaniye traces against road obstacles.
Or deformed replace the lower levers and a bar of the stabilizer with cracks. As a result of deformation of a cross-piece of a frame, levers, bars of the stabilizer and a front of a body change the angles of installation of wheels and there is impossible their adjustment. Check an inhaling of fasteners.
Removal and installation of a forward suspension bracket
1. Slow down the car the parking brake.
2. Raise and establish a forward part of the car on a reliable support. Remove the corresponding wheel.
3. Rasshplintuyte also turn off a nut of a finger of the spherical hinge of steering draft.

Fig. 4.2. A stripper for a vypressovka of a finger of the spherical hinge of steering draft from a rotary fist: 1 – rotary fist; 2 – case; 3 – screw


4. A stripper (fig. 4.2) to a vypressuyta a finger of the spherical hinge of steering draft from the rotary lever.
5. Rasshplintuyte also turn off nuts of fingers of spherical hinges on both sides.

Fig. 4.3. A stripper for a vypressovka of a finger of the spherical hinge of the lower lever of a suspension bracket: 1 – case; 2 – cheek; 3 – bolt; 4 – screw


6. A stripper (fig. 4.3) to a vypressuyta fingers of spherical hinges from the lower levers.
7. Disconnect a bar of the stabilizer and the lower levers from a cross-piece of a frame and remove a stabilizer bar with the lower levers from the car.
8. Remove from a guide of blocks a support with the wheel cylinder. Suspend a support to a body on a wire, watching that the brake hose did not stretch and was not overwound.
9. Turn off nuts of fastening of the top support and remove a suspension bracket rack from the car.
10. You carry out installation of a forward suspension bracket upside-down.

Dismantling and assembly of knots of a suspension bracket
1. Disconnect the lower lever 28 (see fig. 4.1) from a bar of the 27th stabilizer.
2. Check a condition of rubber pillows 34, persistent washers and the plastic plug 33 in an opening for fastening of a bar of the stabilizer. Replace worn-out pillows and plugs.

Fig. 4.4. Device for a press fitting of rubber-metal hinges of a forward suspension bracket: 1 – support; 2 – plug; 3 – pusher


3. Replace the damaged and deformed rubber-metal hinge of the lever. For this purpose to its vypressuyta from the lever also press new by means of adaptation (fig. 4.4), previously having greased the hinge with soap solution.
4. Press plastic plugs 33 (see fig. 4.1) in a lever opening carefully not to damage; previously grease them with soap solution.
5. 35 at assembly of a bar of the stabilizer with the lower levers establish basic washers by otbortovka outside, and rubber pillows 34 – dredging towards basic washers.

Fig. 4.5. Flat-nose pliers for removal of spring rings of a protective cover of a rod


6. Before dismantling of a rack release the lower end face of a protective cover 19, having moved with flat-nose pliers (fig. 4.5) a spring ring 8 (see fig. 4.1) on the tank of a damping rack.

Fig. 4.9. Damping rack: 1 – plate of the inlet valve; 2 – the washer is adjusting; 3 – piston; 4 – piston ring; 5 – plate of the perepuskny valve; 6 – release buffer; 7 – tank; 8 – the cylinder is working; 9 – plug; 10 – rod; 11 – tank nut; 12 – ring rubber; 13 – epiploon; 14 – epiploon spring; 15 – a guide with a pipe; 16 – ring; 17 – limiter; 18 – the ring is spring; 19 – spring of the perepuskny valve; 20 – spring of the inlet valve; 21 – compression valve case; 22 – cup; 23 – compression valve spring; 24 – compression valve; 25 – ring; 26 – valve disk; 27 – the disk is throttle; 28 – valve disk small; 29 – valve nut; 30 – the plate is basic; 31 – valve spring


7. Shift the lower end face of a cover above a basic washer on a nut 11 (see fig. 4.9) the rack tank.

Fig. 4.6. Device for dismantling of a telescopic rack: 1 – screw; 2 – spring


8. Squeeze a suspension bracket spring for extreme working rounds the device (fig. 4.6) for compression of springs.

Fig. 4.7. Flat-nose pliers for removal of a cover of a support


9. Flat-nose pliers (fig. 4.7) uncover a support 13 (see fig. 4.1).
10. Record the top support 14 from a provorachivaniye on a rod of a damping rack and turn off a nut 11 on a rod.
11. Sort a rack.
12. Before assembly clear details of dirt.
13. Grease the bearing 10.
14. Fix a cover 19 on the top basic cup by a spring ring 16.
15. Squeeze a suspension bracket spring adaptation for extreme working rounds if the spring was replaced.

       PREVENTIONS
From both parties it is necessary to establish springs of one dimensional group.

16. Completely put forward a rod of the shock-absorber and establish details and knots upside-down.
17. Combine an opening of the top support 14 with lyska on a rod and tighten a nut 11.
18. Remove adaptation from a spring and establish a cover of the 13th support.

Possible malfunctions of racks and shock-absorbers, their reasons and ways of elimination

Damping rack of a forward suspension bracket and shock-absorber of a back suspension bracket
Features of a design
The damping rack and shock-absorber representing hydraulic telescopic two-pipe shock-absorbers of bilateral action with a variable stream of working liquid serve for damping of the mutual fluctuations between a body and wheels arising at the movement of the car.
The damping rack, besides, is the basic bearing element of the directing mechanism of a suspension bracket of forward wheels.
Check of technical condition of shock-absorbers on the car
For a rough estimate of a condition of shock-absorbers shake the car hands for a corner (wing) with an amplitude about 30 mm up-down. In the lower point release hands and count number of damped oscillations. If number of fluctuations no more than 2, the shock-absorber is serviceable; if it is more – the shock-absorber needs under repair or replacement. In the same way check other shock-absorbers.
Check of a damping rack and the shock-absorber of a back suspension bracket at the stand
Operability of a damping rack and the shock-absorber can be determined at the dynamometer stand by working charts.
The working chart is defined according to the instruction attached to the stand after performance not less than 5 working courses at a temperature of working liquid (20±5) °C, the frequency of 1,67 Hz and a piston stroke of 100 mm that corresponds to the maximum speed of the piston of 0,52 m/s (in the middle of the specified course).

Fig. 4.8. An approximate form of charts when checking damping racks and shock-absorbers at the stand: and – the chart of a serviceable damping element; – the chart of a faulty damping element; 1 – excess of liquid ("subtime"); 2 – the emulsion (made foam) liquid; 3 – lack of liquid ("failure")


Curves of working charts have to be smooth, without deviations demonstrating insufficient or excess amount of liquid, its poor quality, and also the wrong assembly or existence of defects of details of valvate system. Resistance of the course of compression and a release determine by the largest forces of resistance And yes In (fig. 4.8), received at removal of the chart. The required values of forces of resistance are given in a technical characteristic of a damping rack and the shock-absorber.

The violations in operation of the car connected with malfunction of shock-absorbers
Malfunction sign
Reason
The car is insufficiently steady at movement along the uneven road (has side demolitions), is inclined to longitudinal rocking
Damping racks or shock-absorbers do not develop normal effort of resistance
Frequent breakdowns of suspension brackets of the car
Damping racks and shock-absorbers have the reduced effort of compression

Dismantling of a damping rack
The damping rack and the shock-absorber have a difficult design and consist of a large number of the details collected with a big accuracy. Therefore sort them only in urgent cases, observing special purity and accuracy.

       NOTE
Repair of the shock-absorber of a back suspension bracket see. "A back suspension bracket".

Technical characteristic of a damping rack and shock-absorber
Parameter
The rack is damping
Shock-absorber
Diameter of the piston, mm
35
27
Diameter of a rod, mm
25
12
Outer diameter of the tank, m
53
48
Resistance force on the valvate mode at a piston speed
0,52 m/s, N (kgf):
at a release


at compression



1415±205
(144±21)

512,5±102,5
(52,2±10,4)



1415±205
(144±21)

512,5±102,5
(52,2±10,4)
Course of a rod, mm
190
250

1. Before dismantling carefully clear external surfaces of dirt and wash out, paying special attention to purity of a nut of the tank.
2. Clamp in a vice a rack in vertical position a rod up so that cheeks of its lower arm were perpendicular to sponges of a vice (at such fastening deformation of a rack is excluded).

Fig. 4.10. A key for an otvertyvaniye of a nut of the tank of a damping rack


3. Extend a rod of 10 (fig. 4.9) up and, holding it in this situation, turn off a key (fig. 4.10) a nut of the 11th tank (see fig. 4.9).
4. Take out a rod with the piston, a guide 15 and an epiploon of the 13th rod and remove from the piston 3 a piston ring 4.
5. Take out from a vice the tank 7 with the working cylinder 8 and pour out liquid in a pure vessel, holding the cylinder.
6. Take out the cylinder and easy blows of a wooden core beat out from it the case of 21 valves of compression.
7. Remove from a rod the 10th epiploon 13, a guide 15 and the buffer 6 of a release.
8. Holding a key for a lyska a rod from a provorachivaniye, turn off a nut of the 29th valve of a release and remove details from a rod.
9. Install the case of 21 valves of compression by three ledges up and remove a cup 22, then take a spring 23 valves and the valve 24.
10. Install the case of 21 valves on ledges and remove a spring ring 25, a conic spring of the 20th inlet valve and a plate of 1 valve.
11. Carefully take out from a flute of a nut of the 11th tank a rubber ring 12.

       PREVENTION
Pay special attention when dismantling a damping rack to the plug of the 9th guide 15, the internal ftoroplastovy covering of which is easily damaged at mechanical influence. It can be washed out plentiful amount of damping liquid and to blow compressed air.

12. After dismantling wash out details gasoline and attentively examine them.
13. Replace a rod if on its working surface there are scratches, teases, zaboina or traces of corrosion from wear of the chromeplated layer, and also at damage of the top carving end.
14. Replace a rod epiploon at wear or damage of ring combs on its internal working surface.
15. Replace the sealing rubber rings damaged when dismantling or strongly deformed.
16. Replace the shock-absorber cylinder if on its working surface there are scratches, teases or traces of corrosion.
17. When replacing the cylinder it is recommended to replace the piston and rings because of scratches and zadir on their working surfaces.
18. Replace a guide of the 15th rod if on the plug 9 the ftoroplastovy covering is worn-out or damaged.
19. Other details wear out slightly and need replacement at breakages or other damages.
20. Collect a damping rack upside-down, having greased previously working surfaces of an epiploon of a rod with TsIATIM-201 lubricant (State standard specification 6267-74).
21. You carry out filling of a damping rack with working liquid after installation to the tank of the working cylinder. The volume of liquid is specified in marking on the shock-absorber case (the brand and volume of working liquid are also specified in appendices 3 and 6). At the same time fill in liquid in the working cylinder up to the top, and surplus – in a cavity between the cylinder and the tank.
22. You carry out assembly of the top knot of consolidation and an inhaling of a nut of the tank at the rod extended in extreme situation.
23. After assembly pump over a damping rack, moving a rod up and down. At correctly assembled and serviceable shock-absorber after pumping of 4-6 times manually (a piston stroke not less than 100 mm) resistance at the beginning of movement of a rod has to be felt. Efforts when moving a rod have to be less efforts at its movement down up.
24. For check of tightness leave a damping rack in horizontal position on 10–12 h with completely drowned rod.

Non-demountable damping rack

Fig. 4.11. Non-demountable damping rack of a forward suspension bracket


The Izh-21261 cars along with folding damping racks of a forward suspension bracket are completed with damping racks of a non-demountable design of 2126-2905010-70 (fig. 4.11) of production of LLC Lada komplekt. The dimensional and adjusting sizes of new non-demountable racks (further called "racks") same, as at folding.
Repair of non-demountable racks comes down to their replacement. The racks installed on the Izh-21261 car have to meet the following requirements. Racks have to be covered Eska-0239 soil-enamel of gray color or TsINEP soil of also gray color. The site of a rod 1–1 has to be covered with state standard specification 10877-76 K-17 lubricant.
On sites of surfaces, And, designated by dash-dotted lines, ledges, violations of density are not allowed. On edges of openings of L and M agnails are not allowed.
Openings of L and M have to include freely calibers with two parallel cores with a diameter of 12 and 14 mm located at distance of 69,9-70,1 mm.
The rack has to be tight. Check is made by pumping not less than 30 with with a frequency of 60 cycles a minute and the course of 100 mm at the stand for pumping or for removal of working charts. At the same time temperature of a rack should not exceed 100 °C. After pumping of a leak should not be. The subsequent check consists in endurance during 12 h in horizontal position at a temperature of +20 °C, at the same time the rod has to be put forward to the full. Emergence of traces of liquid on an external surface of a rack after tests is not allowed.
The effort of shift of a rod should not exceed 50 N (5 kgfs). Check of effort of shift is made at a temperature of 20 °C, the rack fastens horizontally and is pumped over by five full cycles "stretchings compression". By the end of a rod the dynamometer fastens, the stretching effort on a rod until a rod start of motion smoothly increases. The effort of the beginning of shift of a rod is determined by the indication of a dynamometer. It is allowed to make check of effort of shift of a rod by the annex to the case of a rack of the control freight suspended for a rod. Control freight has to be put without breakthroughs, smoothly. The movement of the case of a rack concerning a rod at any their situation after the appendix of control freight demonstrates that the effort of shift of a rod does not exceed the total weight of control freight and parts of the racks moving together with freight. The weight of moving parts has to be accepted by 40,88 N (4,088 kgfs).
Work of racks has to be silent, the scratch, knock are not allowed. Noise level should not exceed 75 dB.
Efforts of resistance are resistant at a piston stroke of 100 mm, temperature of 20 °C and with a frequency of fluctuations of 20 min.-1 there have to be equal (720±100) N, with a frequency of fluctuation of 60 min.-1 – (960±120) N at a release and (250±50) N at compression. Removal of working charts and determination of the maximum efforts of resistance of racks at the course of a release and compression are made at special SI-95, SIA-01 stands or others, providing back and forth motion of the piston or working cylinder under the law of fluctuations close to sinusoidal.
Racks have to pass bench tests for durability in number of not less than 2 million cycles of single-frequency fluctuations at the course of a rod of 100 mm, frequency of fluctuations of 3,1 Hz, the side load of 1 kN enclosed in a zone P and temperature of the case (70±10) °C taken in a zone P. Change of efforts of resistance should not exceed 25% of initial. Liquid loss no more than 10% of the initial volume equal (390±5) cm3 is allowed. Tests are carried out at N-8531 stands. The rack is established at the stand vertically by a rod up or at an angle no more than 30 ° from a vertical by means of the special fasteners imitating fastening on the car. Constant side loading is put to the rack tank in a zone of the directing plug (zone P). In order to avoid an overheat, water cooling is brought to a rack. Temperature is measured in a zone of knot of consolidation of a rack – (70±10) °C.

Replacement of the hug bearing of a forward wheel

Fig. 4.12. A nave with a brake disk and a rotary fist of a forward wheel: 1 – nave; 2 – hug bearing; 3 – lock ring; 4 – screw; 5 – washer; 6 – rotary fist; 7 – bolt of fastening of the hinge; 8 – hinge spherical; 9 – brake board; 10 – disk brake; 11 – hairpin; 12 – nave nut; 13 – washer


In a nave of 1 (fig. 4.12) of a forward wheel the two-row radial-stop ball bearing 2 of the closed type which in use does not demand adjustment and lubricant is installed.

       PREVENTIONS
Needlessly do not press off the bearing from a nave as it at the same time collapses. In use you watch an inhaling of a nut of fastening of a nave.

If at the movement there was a noise, and when rocking of the hung-out wheel – a side play, there is a probability that the bearing failed. The defective bearing needs to be replaced.
1. Raskontrite also weaken an inhaling of a nut of the 12th nave on the car standing on the earth.
2. Remove a wheel.
3. Having turned off two bolts of fastening of a guide of blocks to a rotary fist, remove the brake mechanism and suspend it to a suspension bracket spring on a wire, watching that the brake hose did not stretch and was not overwound.
4. Finally turn off a nut of the 12th nave and remove a persistent washer 13.
5. Press a nave with a brake disk 10 from a rotary fist 6. If a half of an internal ring remained on a pin of a rotary fist, press it.
6. Remove a lock ring 3.
7. Carefully clear a nave surface at the bearing exit not to allow a nave edge vykrashivaniye at a bearing vypressovka.
8. Vypressuyte the bearing from a nave, putting effort to an internal ring of the bearing.
9. Carefully clear a pin of a rotary fist and a nave of dirt.
10. The nave with the damaged carving of openings under bolts of fastening of disks of wheels needs to be replaced.
11. Press the new bearing in a nave, putting effort only to an external ring of the bearing.
12. Establish a lock ring 3 and a napressuyta a nave on a pin of a rotary fist.
13. Establish a persistent washer 13 and screw a nut of the 12th nave.
14. Finally tighten a nave nut the moment of 180-220 N · m (18–22 kgfs · l) on the car standing on the earth, and its zakontrita.