3. Major Performance Parameters of HW19710T
New Type of Transmission
Transmission Series
Rated Input Power
（KW/Ps）
Rated Input Torque
（N·m)
Max. Input Speed
(rpm)
HW19710T 340/ 420 1900 2200
HW19710TC 340 / 420 1900 2200
Low Gears High Gears
Reverse 1 2 3 4 5 6 7 8 9 10
14.01
3.2
14.36 10.66 7.88 5.82 4.38 3.28 2.44 1.8 1.33 1.00
4. Numbering Rule for HW19710T New Type of
Transmission
HW 19 7 10 T C
CNHTC
HOWO
Nominal Input Torque
Number of forward gears
1. HW Ten-speed Transmission Series
Seven series
All synchromesh
Overdrive gear
10. The structure and work principle of shift air assisted
shift operation adopts air-assisted mechanism which make the shift labor-saving and easily.
when you pull the rocker left, the push lever c will drive the shaft i left at the same time, which makes the right mandril (顶
杆） h open the valve g. the compressed air will enter the chamber A from the port 1 through the air passage of the shaft i,
and then ,the air enters into the C chamber through the air hole which is at the right side of the piston rod d, the air in
chamber B will exhaust through the air hole at the left side of the piston and the core hole of the push rod C assembly. the
piston will be driven left by the compressed air , the piston rod will move to left, it drives the pin roll B and rocker head left.
when you pull the rocker right, the push lever c will drive the shaft i left at the same time, which makes the left mandril e
open the valve f. the compressed air will enter the chamber A from the port 1 through the air passage of the shaft i, and
then ,the air enters into the B chamber through the air hole which is at the right side of the piston rod d,
the air in chamber C exhaust to the atmosphere through the yellow passage in the picture . the piston is pushed right by
the compressed air, the piston will drive the piston rod right , the piston will push the pin roll B and rocker right.
16. 1. The main gear box adopts all synchromesh, all bevel gear and
single intermediate shaft; the rear auxiliary gear box uses planetary
mechanism, and this is the optimized structure of the transmission
installed in the highway-used heavy load truck in today’s world. The
reliability, economy and carrying capacity of the transmission will
be enhanced obviously.
2. The main auxiliary gear box increases mechanical interlock
mechanism, and this efficiently prevents the misoperations which
will cause early failure of the synchronizer of the rear auxiliary gear
box.
3. The lubrication system adopts coexisting of splashing, enforcement
and spraying. The synchronizer and bearing in the transmission
adopt compulsory lubrication, and the others adopt splashing and
spraying lubrication. This remarkably enhances the service life of
the transmission, at the same time, it can adapt to the working
conditions with up and down ramps for a long time.
4. The housing of the transmission adopts cylindrical structure. At the
time increasing the strength of the housing, this reduces the
assembling difficulties.
17. Cooler
Spray pipe
Inner bore pipe of output shaft
Oil pump
Oil suction pipe and
filter screen
Filter
Oil distributing
ring
18. 5. The newly designed top cover, integrating self-lock and interlock of
the gears, has dramatically enhanced the reliability and repair
simplicity of the transmission.
1-Self-locking block with the shape of sector 2-Gear shifting shaft 3-Gear-shift inghead
4-Interlocking fork 5-Self-locking pin shaft
Shift a gear
Gear selection
Spring compression
19. Self-locking pin shaft
Self-locking spring
End cover of the
small cover
Right end cover of the
small cover
Dustproof cover
Gear-shifting head
Interlocking fork
20. Operating Principle of Double-cone Synchronizer
When shifting a gear, move the gear
sleeve to the right, driving the steel
ball and block to move rightward, the
block pushes the locking ring to the
right, and the locking ring pushes the
double-cone ring to the right, by now
the two cones are producing friction,
making the locking ring turn half a
tooth angle, and preventing the gear-
shifting sleeve from continuing to
move rightward. Along with the
increase of gear-shifting force, the
thrust of the gear sleeve to the
locking ring is increasing, and the
friction between the double cones is
increasing. Make the speed of
double-cone ring, locking ring and
single cone ring the same by means
of friction, i.e. the speeds of gear-
shifting sleeve and the combination
gear plate are synchronized. At this
time, the resistance of friction and
locking ring to the gear-shifting
sleeve fades away simultaneously,
and the gear-shifting sleeve and the
soldered tooth of the bond plate
could be engaged successfully and
without impact.
Synchronizer flash
Synchronizer video
Steel ball Pushing block
Gear-shifting ring
Spring
Shift a gear Locking ring
Double-cone ring
Toothholder
Main shaft
Gear
Engaged
gear plate
Single cone
ring
Bushing
22. 1. Assembling of Output Shaft Assembly
Gear ring of fourth speed /fifth speed gear
Gear ring of second
speed /third speed gear
First speed gear
synchronizer
Second speed gear synchronizer
Gear ring of first speed
/reverse gear
Third speed gear synchronizer
Fourth speed gear
synchronizer
Rear bearing of output shaft
Oil distributing pan
Sun gear
Reverse gear
First speed gear
Second speed gear
Third speed gear
Fourth speed
gear
Front bearing of
output shaft
23. (1) Output shaft (2)Install the needle bearing of the second speed gear
26. Install the
needle bearing
Tightening torque of
locking nut: 420-
470Nm, and tighten
the locking port
Install the third speed
/fourth speed gear, etc.
in a similar way
27. Thermal insert the
front bearing of the
output shaft
Turn the output shaft assembly
into the upright shape
29. Thermal insert rear bearing
of the output shaft
Move the oil sump
downward and install
the thrust pad
30. Install the clamp spring
Install the oil
distributing pan
Adjustable pad
Note: The thickness of the
adjustable pad shall be subject to
not loose in the axial direction
and installing of the clamp spring.
32. 2. Assembling of Rear Auxiliary Gear Box Assembly
Output shaft
Planetary gear
Planet carrier
Planetary gear shaft
Rear auxiliary gear box body
Bolt for tightening the planet carrier and
output shaft
Bolt for tightening the fixed plate of
the gear ring
Large gear ring
Fixed plate of the gear ring
Fork shaft assembly
33. Oil hole points to the
center of the circle
Planetary gear
Locating sleeve
Spring pin
Planet carrier
Install planetary gear
Oil hole points
away form the
center of the
circle
34. Load it into
the thrust
bearing
Press mounting of the
output shaft
Assemble the planet carrier
and output shaft as a set
Install the gear ring
and gear ring bracket
Install the fixed plate
35. Install the low gear
synchronizer
Alignment
Press in the
toothholder
Install the bushing
38. Install the odometer at
the alignment position
Press in the rear housing
Install the keep plate at the
alignment position
Press in flange
39. Tightening force of
the nut 200-240 Nm
Tightening force of large
bolt 1000-1300 Nm
Install the
piston
Install the
cylinder
Tightening force of
the bolt 41-51 Nm
40. Press in locating sleeve
Tightening force of the bolt with
fastening glue 70-80 Nm
41. 3. Assembling
note：——Cover board 21-25Nm.
——Oil filling/drain bolt 120-140Nm.
——End cover of input shaft, etc. 41-51Nm.
Switch 45-55 Nm
Large nut 1000-1300Nm
35-55Nm
44. Clearance Adjustment Between the Output Shaft and
Intermediate Shaft
• The axial clearance
between the output
shaft and
intermediate shaft
shall be adjusted by
the adjustable pad
(shown as in figure).
• Use the depth
indicator to measure
the distance from
cover base A to end
face of bearing B1
and B2, shown as h1
and h2 respectively.
Depth indicator：
Depth indicator
45. • Use the depth
indicator to measure
the distance from oil
pump base A to end
face of step B1 and B2,
shown as h1 and h2
respectively.
Calculate the thickness of the adjustable pad.
1. Thickness of axial adjustable pad of the output shaft σ=H1-h1-(0-0.06)。
2. Thickness of axial adjustable pad of the intermediate shaft σ=H2-h2-(0-0.06)。
3. Difference in every 0.06 of the thickness of the adjustable pad shall be a specification, and supplied as
a set.
Depth indicator
47. Note: There are adjustable pads of the output shaft and intermediate shaft under the oil pump, adjust them
precisely as required.
Spray pipe
Tightening force of the bolt
Filter screen of the oil pump
Oil pump
Sun gear
49. Operation Requirements
1. Lubricant Brand and Type. The transmission shall be filled with gear
lubricant with excellent quality, whose performance shall not lower than
Grade 85W/90GL-4 or 85W/90GL-5 vehicle gear oil.
2. Oil Level. Check the oil level through the inspection port at the side o the
transmission housing. The oil level shall reach the lower edge of the
inspection port, and the lowest level shall not be less than 5mm to the
lower edge of the inspection port. Too much oil charge will cause the
increasing temperature of the transmission and oil leakage. Too little oil
charge will cause poor lubrication of the parts, severe cases can result in
accident of burned-out transmission.
It is very important to operate the transmission correctly and reasonably, and
maintain it regularly, which will guarantee the vehicle running reliably and
extend its service life. Please follow the requirements;
50. 3. Inspection of Oil Level
Check the oil level regularly. The vehicle shall be stoped on the level road
when checking the oil level. Due to volume expansion of the hot oil, you
cannot immediately check the oil level just after the running of the vehicle in
order to measure it correctly. You can check it when the oil level is steady
and the oil is a little cool.
4．Replace the Lubricant
In order to prevent chemical reaction between different types of lubricant,
when replace the lubricant, make sure that what filled shall be of the same as
the original.
5．Oil Changing Period
When changing the lubricant, drain out the original lubricant.
It is necessary to change the lubricant after the new transmission has run
2000~5000Km.
Check oil level and leakage for service every 5000Km, replenish(补充） it if
necessary, and clean the filter screen assembly.
Change the lubricant for service every 50000 to 80000Km.
Operating Requirements
51. 6． Working Temperature
During continuous working of the transmission, the max. temperature shall
not be more than120℃, and the min. shall not be lower than -40℃.
When the working temperature exceeds120℃, the lubricant will go bad, and
that will shorten the service life of the transmission.
Any one of the following conditions will cause the working temperature of the
transmission over 120℃：
a) Operate continuously at the running speed of less than 32km/h.
b) High engine speed.
c) High ambient temperature.
d) airflow surrounds the transmission.
e) Exhaust system is too close to the transmission.
f) Overspeed running with high power.
Operating Requirements
52. 7．Towing or sliding
When the transmission is operating, the shaft and gears of the transmission
rotates constantly, forming splash and compulsory lubrication which could
operate normally and supply sufficient lubrication to the transmission. But
with the connection of the drive train and rear wheels landing, when the
vehicle is towed, the gear of the intermediate shaft and the gear of the main
shaft of the main gear box will not rotate. By now, the splash and compulsory
lubrication will not be operating, while the main shaft is towed by the rear
wheels, rotating with high speed; thus, this will seriously damage the
transmission due to lack of lubrication.
Operating Requirements
In order to prevent this from happening,
please pay attention to the following
points:
Do not glide with the transmission in neutral when the engine is off;
Do not coast with the transmission in neutral when the clutch pedal is
depressed;
If it is necessary to tow the vehicle, you can pull out half a shaft or uncouple
drive shaft, and also you can make the driving gear towed away the ground.
53. VII. HW19710T New Type of Transmission
Precautions
▲ HW19710T transmission is with low
gears range and high gears.
Switching from one range to the
other relies on the high/low switch on
the handle ball. It is not allowed to
stop the vehicle at high gears.
▲ The transmission is with low gears
and high gears. When switching from
one range to another, it must be
done in neutral.
▲ It is not allowed to coast(滑行） in
neutral at a high speed for a long
time or tow without any measures.
▲ The gear could be shifted only when
the clutch is depressed, for it is
controlled by all synchromesh
transmission.
▲ It is strictly prohibited that shift a gear
for the main gear box at the time
when switching from one range to
the other.
Instrument
panel
54. VIII. Troubleshooting
first, know about the operating principle of the transmission in detail.
1. Gear stuck（齿轮卡住）
It is caused by the driver who switches the high/low gear at the time when
shift a gear in the main gear box. The method of troubleshooting is to try
to ventilate（通气） the cylinder, make it reset or remove the cylinder cap
to push the piston into the front end. The trouble could be cleared.
2. Difficult to shift a gear
Difficult to shift a gear divides into difficult to shift all gears and difficult to
shift individual gears. Difficult to shift all gears is mainly caused by the
clutch drag, and improperly adjusted and worn shift lever. Difficult to shift
individual gears is mainly caused by failure of synchronizer at the
corresponding gears and defective manufacture.
3. Gear-stripping
It is divide into gear-stripping of the main gear box and the auxiliary gear
box. Gear-stripping of the main gear box shows that the shift lever
rebounds（弹回） to the neutral position. The gear-stripping of the
auxiliary gear box shows that the shift lever cannot be moved, and the
vehicle is in the status of neutral position. The main reason is caused by
the broken support bearing at the corresponding gear position.
55. Preliminarily, know about the operating principle of the transmission in detail.
4.Synchronizer burnt
synchronizer burnt is one of the most common problems about this
transmission. It caused by many reasons, which are the lubrication oil is
very dirty or very short, some drivers don’t do the service as requirement
until the gear box has malfunction. And some mechanic don’t clean the
parts, even install the parts with sand directly which will short the service life
of the gear box. The driver’s bad habit is other factor causing damage the
synchronizer.
56. • 5. second gear and third gear plate damage
it is caused by driver’s bad habit, some drivers have little knowledge about
how to use gear box. They like driving at high speed and jumping the gears
when shifting the gears which cause the gears of the gear plate wearing
quickly and even cracked it. And bad quality of the lubrication oil also make
the gear plate damage easily.
