Foton Series Light Bus. Service Manual — part 13
OPERATION AND MAINTENANCE MANUAL FOR FOTON VIEW SERIES LIGHT BUS
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Figure 10-4-1 Rear Axle Assembly (1)
Figure 10-4-2 Rear Axle Assembly (2)
1-Rear axle assembly; 2-Final drive assembly; 3-Nut; 4-Flange of driving gear; 5-Dust boot; 6-Oil seal; 7-Front bearing; 8-1 type
hexagon nut; 9-Spring washer; 10-Stud, axle housing bolt; 11-Final drive housing; 12-Bearing cap; 13-Pack of hexagon bolt and spring
washer; 14-Bolt; 15-Adjusting locking plate of bearing nut; 16-Spacer; 17-Rear bearing; 18-Washer; 19-Driving gear; 20-Differential
bearing; 21-Adjusting nut; 22-Driven gear; 23-Bolt; 24-Differential housing; 25-Thrust washer; 26-Differential drive gear; 27-Planteary
gear shaft; 28-Planteary gear; 29-Thrust washer; 30-Differential pin shaft; 31-Rear axle housing welding assembly; 32-Rear axle housing
oil shield stand; 33-Normally close air plug; 34-Filler plug; 35-Filler plug washer; 36- filler plug sub assembly; 37- snap ring; 38-Fixing
sleeve of bearing; 39-S type oil seal; 40-Annular ball bearing; 41-Bearing carrier; 42-K type oil seal; 43-Oil baffle disk of brake drum;
44-Rear wheel hub bolt; 45-Washer of oil baffle disk of brake drum; 46-hafl shaft; 47-Washer; 48-Brake drum; 49-Left brake assembly;
50-Right brake assembly; 51-Nut; 52-halfshaft bolt.
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Chapter 10 Chassis Structure and Service
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The function of final drive is to decelerate, increase torque and change direction of power transfer, and
finally transfer power to driving wheels to push the vehicle to run. BJ6536 series bus applies single stage hypoid
gear final drive. Its structure is shown in Figure 10-4-1. It consists of a pair of hypoid gears (driving and driven
gears) and supporting device. The driving bevel gear is integrated with its shaft, its front spline connected with
half shaft through the driving gear flange, and it is supported on the bearing carrier through two bevel roller
bearings. Driven bevel gear is connected to differential housing with bolts; and the differential is supported in the
mounting hole of axle housing through two bevel roller bearings. The projection of driving gear bearing can be
adjusted by inserting the adjusting washer between the internal bearing carrier. There are interconnected oil
passage between the bearing and the final drive housing.
Driving and driven bevel gears apply splash lubrication method. Rotation of driven gear makes the gear oil in
the axle housing splashing onto driving and driven bevel gears. Driving gear bearing is lubricated through the oil
passage cast in the axle housing.
2. Differential (see Figure 10-4-2)
Differential is of ordinary plantearyary gear type, composed by two halfshaft gear, four plantearyary gears,
one cross shaft and RH/LH differential housing.
RH and LH differentical cases are combined with bolts. Final drive driven bevel gears are fixed with bolts to
RH differential case flange, cross shaft journals are set onto the groove on RH/LH differential case’s fitting face.
Each journal has a plantearyary gear on it. Two halfshaft journals are mounted into the mounting holes in RH/LH
differential cases. Each plantearyary gear meshes with two halfshaft gears at the same time, and halfshaft gears
connect to halfshaft via spline.
3. Halfshaft
Rear axle halfshaft is a piece of solid shaft with flange. It transfers halfshaft gear output torque to driving
wheels. It spline-meshes with halfshaft via its inner end, and it outer end connects rear wheel hubs. This type of
supporting can only avoid bending torque to internal end of halfshaft, while the external end will bear all bending
torque.Therefore, it is called “semi-suspension” support.
4. Rear Axle Housing
Rear axle housing is made up of gear bracket, oil seal, left and right shaft tube etc., the interior of which is
used to install final drive, differential and propeller. Exterior of rear axle housing is connected with frame through
suspension and brake bottom plates will be installed on both ends of it. The driving axle housing bears various
acting forces and torques transferred from suspension and wheels. Rear axle housing of BJ6536 series bus is of
integral welding type. The collar fixing brake bottom plates is welded on the rear axle shell. There are air bleed
valve and oil drain plug on the rear axle housing, and there are oil filler plug on the bracket cap.
10.4.3 Technical Specifications for Check and Repair
1. Driving gear and driven gear of final drive
(1) Check final drive gears for damage, wear and meshing strength at clockwise and counter-clockwise
rotations. Repair minor injury and replace parts in the events of scratch, peeling, cavity, crack or excessive wear.
Replace drive/driven gear in pair.
(2) Check drive gear shaft journal that supports bearing and small end retraining ring groove for wear.
Repair or replace parts if wear exceeds limit
2. Check differential plantearyary gears, halfshaft gears, cross shaft and differential housing
Check contacting faces among differential plantearyary gears, halfshaft gears and differential case for wear,
and measure fitting clearances.
a)
Check fitting clearance between plantearyary gear inner hole and cross shaft journal. Replace parts if
clearance exceeds limit.
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b) Check fitting clearance between halfshaft gear spline groove and halfshaft spline groove. Replace the
part worn more or replace them both
c)
Check fitting clearance between halfshaft gear shaft journal and mounting hole in differential case.
Replace the part worn more or replace them all.
d) Check plantearyary gear and halfshaft gear thrust washer for thickness and wear. Replace parts if
thickness or wear exceed limit.
Table 10-4-1 Wear Limit of Final drive and Differential and
Meshing patch Standard (mm)
Description
Service limit
Fitting clearance - front bearing of driving bevel gear 35KC802
(JK) and housing
0.02
Fitting clearance - rear bearing of driving bevel gear HR30306C
(JK) and housing
0.02
Fitting clearance - front bearing of driving bevel gear 35KC802
(JK) and journal
0.02
Fitting clearance - rear bearing of driving bevel gear HR30306C
(JK) and journal
0.02
Inside diameter of planteary gear hole and outside diameter of
cross shaft
0.25
Groove width of reference circle of halfshaft spline groove and
tooth thickness of spline reference circle.
0.35
Journal of halfshaft and inner diameter of differential housing
hole
0.25
Fitting clearance - differential bearing (NSK17887/17831) and
housing
0.05
Fitting clearance - differential bearing (NSK17887/17831) and
journal
0.03
Radial clearance of rear propeller bearing (4G-180308)
0.15
End clearance of driving bevel gear shaft
0.05
Lateral clearance between driving bevel gear spline and flange
keyway
0.20
End clearance of planteary gear
0.50
Contact area
During assembly, the contact area should cover 2/3 tooth length and is 2~4mm away from
small end surface. After loading, the contact area should cover whole tooth length and is
generally 0.8~1.6mm away from the tooth top.
3. Adjustment of pretension of driving bevel gear bearing:
During adjustment, lubricate the bearings thoroughly before installation of oil seal. After tightening the
driving gear, rotate the driving gear to make the bearing rollers contact properly with inner and outer rings of
bearing. Before making measurement at flange bolt hole, rotate the driving gear for 5 turns in the same direction.
If the pretension is not in compliance with above requirements, increase or reduce the adjusting washers between
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Chapter 10 Chassis Structure and Service
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the two bearings of driving gear until it is proper. The thicknesses of adjusting washers are 0.05mm, 0.15mm and
0.25mm.
After adjustment of pretension, draw a marked line at end of driving gear and on end surface of tightening
nut, so that the tightening nut still can be tightened along original marked line after bearing cap has disassembled,
or when to install oil seal and reassemble.
4. Assembly of driving and driven bevel gears, measurement of side clearance and adjustment of tooth
face contact area
Inspect and adjust the engagement of driving bevel gear of final drive and driven bevel gear. Check driving
and driven bevel gears for correct engagement tooth face contact area and side clearance. If it is not correct, move
the driven bevel gear left and right and the driving bevel gear back and forth to adjust. The thicknesses of
adjusting washers are 0.25mm and 0.1mm and total thickness is within 1.25~2mm.
See Figure 10-4-3 for check and adjustment methods for tooth face contact area of driving and driven bevel
gears and side clearance.
Figure 10-4-3 Adjust meshing area of drive/driven bevel gear
▲ Check and adjustment – gear meshing area
Divide driven gear circumference into 3 sections, coat a thin layer of red lead oil on gear face at each 2-3
teeth on each section. Turn driven gear while excerting some resistance from drive gear. Observe mesh patch
position on driven gear. As driven gear convex face is main working face, it needs higher requirement than
Contact position
Normal contact
Driven gear is too
close to driving
pinion
Driven gear is too
far from driving
pinion
Driving pinion is
too close to driven
gear
Drive pinion is too
far
from
driven
gear
1. select to use thinner pinion shim
2. move driven gear from drive pinion to
adjust gear clearance
Drive/driven gear meshing area adjustment
A
bno
rm
al
con
ta
ct
A
bno
rm
al
con
ta
ct
A
bno
rm
al
con
ta
ct
A
bno
rm
al
con
ta
ct
Cause
Steps of adjustment
1. select to use thicker pinion shim.
2. move driven gear closer to drive
pinion to adjust gear clearance
1. select to use thicker pinion shim.
2. move driven gear closer to drive
pinion to adjust gear clearance
1. select to use thinner pinion shim
2. move driven gear from drive pinion to
adjust gear clearance
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concave face does. Adjustment is made mainly based on convex mesh patch.
Meshing area adjustment is made by means of changing front/rear positions of drive/driven gears. There are
shims of different thickness. Add or reduce shim number to adjust correctly drive/driven gear meshing area.
▲ Check and adjustment – tooth side clearance
In normal meshing condition, correct tooth backlash ange is 0.13-0.18mm (measuring with magnetic seat dial
indicator). Adjustment on it should be made together with the adjustment on meshing area. Above mentioned
adjustment method is also applicable. In the event backlash of drive/driven gears exceed 0.06mm, gears should be
replaced. While meshing condition is ok, it is not allowed to change relating positions among gears to reduce
backlash. Change drive/driven gears in pair.
10.4.4 Road Test and Troubleshooting
In the event that professional test equipment is not available, repaired rear axle can be tested by mounting it
onto vehicle. Using vehicle check/test line can make test and regulation.
Check Description and requirements as follows:
(1) Final drive gear and differential gear should operate well. There should be no gear knock or abnormal
loudness-changing sound at acceleration, deceleration or turning.
(2) Tyres and brake drums should rotate smoothly. There should be no friction with brake pad and any axial
movement or obvious radial play. There should be no noise.
(3) Rear axle noise should not be more than 86dB (A).
(4) After having run for 15-20 minutes, bearing mounting locations and brake drums should not be scalding.
(5) There should be no leaks at oil seal and contacting faces.
After having found and removed faults during test, one should perform running test again.
10.4.5 Typical Faults and Troubleshooting
1. Abnormal sound from rear axle, see table 10-4-4.
While vehicle is driving at normal speed, acceleration, high-speed or turning, one can hear continuous or
intermittent knocking or metal noise from rear axle.
Symptom 1: Noise comes out at acceleration, and reduces or diminishes when gas pedal is released. The
symptom may due to final drive gear convex contacts poorly or is worn seriously.
Symptom 2: Noise comes out when gas pedal is released and diminishes at acceleration. This may due to
final drive gear concave contacts poorly or is worn seriously.
Symptom 3: Noise comes out when vehicle makes turning while diminishes at driving straightforward. This
may due to differential failure.
Table 10-4-4 Abnormal Sound from Rear Axle
Causes
Solutions
1
Incorrect gear contact patch -- higher or
lower
1
Adjust contact patch and tooth side
clearance
2
Insufficient gear fluid
2
Add fluid to standard
3
Excessive play or worn — drive gear bearing,
differential bearing and wheel hub bearing
3
Readjust bearing pre-tension or replace
bearing
4
Excessive play — driven gear bolt
4
Fastening
5
Excessive clearance — halfshaft spline
5
Replace halfshaft or halfshaft gear
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Chapter 10 Chassis Structure and Service
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Causes
Solutions
6
Foreign matter in axle housing
6
Remove foreign matter
7
Foreign matter in brake drum
7
Check and remove foreign matter
8
Worn-out differential gear or gasket
8
Replace worn-out parts
9
Tooth peeled or damaged
9
Replace drive/driven gears
10
Gears mesh too tight or loose
10
Readjust mesh clearance
2. Oil leak, see table 10-4-5.
After vehicle has stopped, fluid trace or fluid weeping from connecting spots is found.
Table 10-4-5 Oil Leak
Causes
Troubleshooting
1
Excessive gear fluid
1
Reduce to standard level
2
Oil seal damaged — drive conical gear shaft
2
Replace
3
Vent hole clogged
3
Clean or replace
4
Bolts loosened or gasket damaged — axle case
to final drive case
4
Fasten bolt or replace parts
5
Crack or sand inclusion — rear axle case/ final
drive case
5
Repair sand inclusion or replace
6
Worn-out rear wheel hub oil seal, grease enters
brake drum
6
Replace oil seal, clean brake drum
3. Rear axle overheating, see table 10-4-6.
After a serviced or new vehicle has driven for a period of time during break-in period, its rear axle case,
differential case, wheel hubs and brake drums become scalding (drums normal operating temperature should not
be 70℃ more than ambient temperature, and operating temperature on rear axle, differential case and wheel hubs
should not exceed 65℃).
Table 10-4-6 Rear Axle Overheating
Causes
Solutions
1
Bearing is adjusted too tight
1
Re-adjust
2
Oil seal is too tight
2
Lubricate lip and let break in at low speed
3
Short gear fluid
3
Add fluid to standard
4
Smaller gear meshing clearance
4
Re-adjust gear meshing clearance
5
Brake shoe contacts drum
5
Adjust pad clearance
6
Rear axle case is bended or distorted
6
Adjust bended/distorted parts or replace
4. Early abnormal wear – Final drive gear
After driving a period of time or several thousand kilometers, new or overhauled vehicle may be subjected to
severe gear teeth wear at final drive’s drive/driven conical gears. Using wrong rear axle fluid may be the most
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possible cause, i.e. not the required hypoid gear fluid. To transmit turning torque, hypoid gear teeth rub to each
other heavily, thus lubricant film on them is prone to be removed. If general gear fluid is used on them, gear face
might be injured or worn quickly, this will greatly shorten their life. Therefore, one must use hypoid gear fluid
with scratchproof additive to reduce friction force and improve operating efficiency.
10.5 Front Axle
10.5.1 Main Technical Parameters of Front Axle
Main Technical Parameters of Front Axle (with BJ491EQ1 engine)
Sn
Item
Data
1
Type
Dual cross arm independent suspension
2
Wheel span (mm)
1450 or 1460
Camber
0º20′±30′
Kingpin inclination
10º50′±30′
Caster
1º15′±30′
3
Front wheel
alignment
Toe-in (mm)
3±1
Left wheel
37º±0.3º
4
Maximum steering
angle of front wheel
Right wheel
34º±0.3º
5
Connecting torque of torsion bar seat and cross
arm (N.m)
142±5
6
Upper cross arm of front suspension assembly
and frame (N.m)
147±5
7
Front suspension assembly brake and upper
cross arm (N.m)
142±5
8
Front suspension assembly brake and lower
cross arm (N.m)
142±5
9
Transverse stabilizer bar assembly
5~7mm thread is exposed on top end of ransverse
stabilizer bar connecting shaft (3~5 threads) and
the tightening toque is 11~13 (N.m)
T
Tightening torque of cam nut (N.m)
200±8
11
Distance between locknut of track bar and fixing
bolt (mm)
445±3
12
Torque of track bar front end locknut (N.m)
120±5
13
The exposed length of track bar screw head
(mm)
50±5
14
Front side height of body (mm)
277
10.5.2 Structure Overview
Vehicle axles includes steering axle, steering transaxle, transaxle and supporting axle. The one on which
steered wheels are mounted is called steering axle. Steering axle can be used with independent or dependent
suspensions. BJ6486, BJ6516 series vehicle steering axle adopts independent suspension.
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Chapter 10 Chassis Structure and Service
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Figure 10-5-1 Decomposing View of Front Wheel Hub Assembly
Disc brake
Drum brake
Outer seat
Bearing
Cotter
pin
Gasket
Grease cap
Lock cap
Washer
Bearing
Wheel hub and disc-type rotor
Brake wheel cylinder
Washer
Front wheel hub
Outer seat
Wheel hub bolt
Front wheel hub
Disc-type rotor
Outer seat
Bearing
Seal ring
Bearing
Washer
Lock cap
Split pin
Grease cap
Brake drum
Outer seat
The parts that can not be reused
Specified torque :
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Figure 10-5-2 Decomposing View of Steering Knuckle Assembly
Disc brake
Drum brake
Steering knuckle
Steering knuckle arm
Lower ball and socket
Dust boot
Washer
Brake wheel cylinder
Wheel hub and
disc-type rotor
Bearing
Lock cap
Washer
Grease cap
The parts that can not be reused
Brake drum
Grease cap
Lock cap
Washer
Bearing
Front wheel hub
Steering
knuckle arm
Steering knuckle
Specified torque:
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Chapter 10 Chassis Structure and Service
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10.5.3 Check and Repair
1. Front wheel alignment
① Check tire for wear and pressure. For 185/195 tire, its front wheel pressure is 325±5kPa, and rear wheel
is 450±5kPa. Air pressure for all 205 tires is 250±5kPa. The air pressure difference between coaxial wheels should
not exceed 5kPa.
② Check for end surface run-out of wheel, the value should be below 1.2mm. (Figure 10-5-3)
Figure 10-5-3 Check for End Surface Run-out of Wheel
① Check front wheel bearing for looseness.
② Check front suspension for looseness.
③ Check steering drive rod for looseness.
④ Check ball and socket joint for excessive looseness.
⑤ Measure heights of front and rear sides of vehicle. The front side height should be 277mm while the rear
side height should be 292mm. Adjust it with torsion bar spring nut.
⑥ Check and adjustment of front wheel alignment
Figure 10-5-4 Measurement of Front Side Height of Vehicle
A. Install wheel aligner according to its manufactuer instruction manual.
B. Check camber, caster and kingpin inclination of wheel as indicated in figure 10-5-5.
Front
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OPERATION AND MAINTENANCE MANUAL FOR FOTON VIEW SERIES LIGHT BUS
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Figure 10-5-5 Front Wheel Alignment
C. Adjust camber. If camber value angle is not within the specified range, turn the adjusting cam to adjust as
shown in Figure 10-5-6. Note: Each scale on the cam corrsponds 18′ camber change. When the cam is turned to a
position 4.5 scale beyond the median line, the adjusting cam can not be turned further.
Figure 10-5-6 Adjustment of Camber
D. Adjustment of caster. If caster value is not within the specified range, turn the nut on support bar to adjust
as shown in Figure 10-5-7. Note: Unscrew one of two nuts on the bearer of support bar, and then tighten the other
nut at the opposite side in the same extent, caster therefore gets adjusted. When to adjust with nut on support bar,
the nut should not be screwed up for more than 3 turns (original position as reference). Each turn of the nut
indicates 30′ caster change.
Kingpin
inclination
Camber
Caster
Front
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Chapter 10 Chassis Structure and Service
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195
·
Figure 10-5-7 Adjustment of Caster
E. Check the toe-in. Measure the toe-in with a toe-in gauge.
1. Disassemble the buckle clamp of protection cover.
2. Unscrew the locknut at end of steering tie-rod.
3. Turn ends of left and right steering tie-rods to adjust the toe-in as shown in Figure 10-5-8. The left and
right turning extent should be equal. Note: Measure lengths of left and right steering tie-rods ends. Make sure they
are equal. The length difference between ends of the two steering tie-rods should be 3.0mm or less.
4. Tighten the locknut of the steering tie-rod with tightening torque of 88N.m.
5. Install the protection cover to its seat and clamp it. Be careful not to make the protection cover distort.
Adjustment of toe-in:
Figure 10-5-8 Check Toe-in (1)
Figure 10-5-9 Check Toe-in (2)
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Figure 10-5-10 Adjustment of Toe-in
D. Check and adjust turning angle of wheel
Figure 10-5-11 Check Turning Angle of Wheel
Figure 10-5-12 Adjustment of Wheel Turning Angle
2. Adjust wheel turning angle:
① Disassemble the cover of steering knuckle limit bolt.
② Unscrew the locknut.
③ Screw up the steering limit bolt.
④ Turn the steerer wheel all the way down, unscrew the steering limit bolt until it contacts with the lower
Front
Inside
Outside
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Chapter 10 Chassis Structure and Service
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197
·
arm.
⑤ Fasten the locknut with the tightening torque as 44N.m.
⑥ Install the cover of steering knuckle limit bolt.
3. Check for side slip:
Check side slip of wheel on a sideslip tester as shown in Figure 10-5-13. The side slip of wheel should be
3.0mm or less.
Figure 10-5-13 Check Side Slip of Wheel
10.5.4 Typical Faults and Troubleshooting
1. Hard steering, see table 10-5-1.
There is large steering resistance during vehicle's driving. This is mainly due to part pairs in steering drive
mechanism are fitted too tightly.
Table 10-5-1 Hard steering
Causes
Solutions
1
Steering knuckle is fitted too tight
1
Readjust steering knuckle washer
2
Tie rod ball joint is adjust too tight
2
Readjust
3
Incorrect toe-in
3
Correct
4
Front wheel misalignment
4
Readjust
5
Low front wheel pressure
5
Inflate tire to specification
6
Poor lubrication on parts
6
Add lubricant
2. Front wheel swing or oscillating, see table 10-5-2.
Front wheels swing or oscillate when they are rolling over bumps, driving on rugged road, or vehicle is
driving at 25km/h and changing speed. This is mainly due to excessive clearance among moving parts of steering
mechanism. Excessive tyre unbalance may also create the symptom.
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Table 10-5-2 Front wheel swing or oscillating
Causes
Solutions
1
Ball joint excessive play — front axle upper/lower
transverse arms
1
Adjust or replace
2
Ball pin excessive play - tie rod
2
Re-adjust or replace
4
Loose front wheel bolts
4
Re-tighten
5
Loose front wheel hub bearing
5
Adjust or replace
7
Elasticness varies - LH/RH torsion bars spring
7
Replace
8
Inaccurate front wheel alignment
8
Re-adjust
9
Tyre pressure difference - RH/LH tyres
9
Adjust to specified air pressure
10
Excessive dynamic unbalance - wheel or brake drum
10
Perform dynamic balance test
3. Driving to one side, see table 10-5-3.
Vehicle cannot drive in straight line or cannot return to straight properly. These are mainly due to vehicle
skewed frame or incorrect front wheel alignment.
Table 10-5-3 Driving to one side
Causes
Solutions
1
Tyre pressure difference — RH/LH tyres
1
Adjust to standard pressure
2
LH or RH brake drum rubbing
2
Adjust brake
3
Different spring elastic ness—RH/ LH torsion bars
3
Repair or replace
4
Uneven wheel base
4
Adjust wheel base
5
Distort front shaft parts, or skewed or distort
vehicle frame
5
Check distort parts, repair or replace
6
Front wheel misalignment
6
Check concerning distort parts that affect
alignment, repair or replace
7
Moving parts are poorly lubricated
7
Add lubricant
4. Excessive or uneven tire wear, see table 10-5-4.
Tire wears excessively after certain mileage. This happens together with other symptoms such as heavy
steering, front wheel swing and drive to one side.
Table 10-5-4 Excessive or uneven tire wear
Causes
Solutions
1
Incorrect tyre pressure
Tyre center face wear — pressure too high
Tyre edge wear – pressure too low
1
Adjust to standard pressure
2
Incorrect front wheel alignment
A. Uneven face wear — tyre inner/outer edge
B. Even circular wear — tyre inner or outer edges
2
Re-adjust and replace parts if necessary
3
Bend or distort steering knuckle
3
Replace
4
Excessive steering knuckle bearing clearance
4
Re-adjust
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199
·
Figure 10-5-14 Abnormal Tires Wears and Correction
10.6 Steering Mechanism
10.6.1 Main Technical Parameters of Steering Mechanism
Main Technical Parameters of Steering Mechanism
Sn
Description
Data
Type
Rack pinion
Transmission ratio
46.67
Total number of turns of the pinion of steering gear (turn)
3.39
1
Steering
gear
Position of steering wheel
LH
Modulus
1.85
Number of rack tooth
30
Number of pinion tooth
8
Pinion arm shaft turning angle(or steering gear arm
swinging angle)
1220º
Reference diameter of the pinion (mm)
φ16.33
3
Rack pinion
sets
Radial circle run-out of rack shaft
0.15
Diameter (mm)
φ390
4
Steering
wheel
Free travel (mm)
25
5
Gross weight of steering gear (kg)
9.5
6
Lubricant
QL-5 rate 80/W90
State
Quick wear on
two shoulders
Causes
Correction
Excessive
camber
Deficient air
pressure or
over speed
Excessive air
pressure or
inadequate
rotation
Deficient air
pressure or
inadequate
rotation
Under cold state, adjust to
specified pressure, perform tire
rotation.
Adjust the
camber
Adjust the
toe-in
Perform static
and dynamic
balance tests
Check
suspension
and tire
rotation
Improper
toe-in
Unbalanced or
skew wheels
Inadequate tire
rotation,
improper
suspension
calibration or
wear
Quick wear on
middle
Feather edge
shape wear
Bald spot
Fan shape
wear
Crack on tread
Single edge
wear
Result
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