Page 1
CRAWLER DOZER
HORSEPOWER
32.4 kW 43.4 HP @ 2450 rpm
OPERATING WEIGHT
D21A-8E0: 3710 kg 8,180 lb
D21P-8E0: 4100 kg 9,040 lb
Photo may include optional equipment.
D21A-8E0
D21P-8E0
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Responsive Operation:
A single joystick on the left controls all speed and directional
changes including:
• 1st to 2nd
• Forward and reverse
• Right and left steering
A single joystick on the right controls all blade functions
including:
• Lifting
• Angling
• Tilting
This left and right joystick system offers unparalleled control
for shorter cycle times.
Easy-to-see Instrument Panel:
Ergonomically arranged meters and lamps make it easier to
check the machine condition. In addition, fuel meter and
dust indicator lamp installed on the panel for easy servicing.
Walk-through Operator's Compartment:
The operator's compartment has a complete walk-through
design, making for easy getting on and off.
C RAWLER D OZER
D21A/P-8E0
WALK-AROUND
Single-lever Steering/Speed/
Directional Change:
All the directional changes are carried out with single lever,
ensuring smooth turn and superior productivity.
12
LH FNRH
12
LH R RH
Float
Down
Angle
N
Tilt Tilt
Up
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Fuel-efficient 4D94LE-2 Engine:
The Komatsu 4D94LE-2 features a
direct-injection fuel system. Intake air
is swirled into the combustion chamber
where it is mixed with injected,
atomized fuel, providing optimum
combustion. This fuel system not only
contributes to greater power and fuel
savings, but also insures reduced
noise and cleaner exhaust. A cushion
mounted engine reduces noise and
vibration.
Efficient HYDROSHIFT
Transmission:
The D21-8E0 is equipped with Komatsu's
unique HYDROSHIFT transmission,
assuring smooth gear shifts, powerful
traction and low fuel consumption.
It consists of a damper and planetary
gear packs. The HYDROSHIFT
transmission makes two previously
incompatible factors compatible: It
efficiently converts engine power to
traction with minimal power loss
through a direct-drive transmission and
it offers smooth, easy shifting through
powershift transmission equipped with
a torque converter.
Unlike ordinary powershift
transmissions with torque converters,
traction does not decrease, even when
the engine is running at partial throttle.
Long Track:
The long track and well-positioned
center of gravity give good machine
balance and make grading operations
and operations on slopes easy. In
addition, the machine can travel over
soft ground easily, and it can escape
from muddy areas without problem.
Simplified Maintenance:
Spin-on type filters are used throughout
the machine, making it easy to replace
filter elements. Air cleaner with
automatic evacuator extends cleaning
interval of the air cleaner.
Automatic De-airation System
with Electric Feed Pump:
Ejects air in the fuel system, simply
turning on the ignition key when
restarting the engine.
Lifetime Lubricated Idlers and
Track Rollers:
The D21-8E0 undercarriage features
longer life and reduced maintenance
costs with sealed track links, and
lifetime lubricated idlers and track
rollers. These eliminate any periodical
greasing for simplified maintenance and
minimize internal pin and bushing wear
for longer service life.
Lubricated Track Links
(optional):
Since the clearance between the link
pin and bushing is lubricated, wear and
pitch elongation are minimized for
extended service life. With lubricated
track, power loss due to pin and
bushing friction are reduced, increasing
operation comfort and performance.
Injection nozzle
Fuel tank
Filter
Injection
pump
Electric
feed
pump
Water separator
HORSEPOWER
32.4 kW
43.4 HP @ 2450 rpm
OPERATING WEIGHT
D21A-8E0: 3710 kg 8,180 lb
D21P-8E0: 4100 kg 9,040 lb
BLADE CAPACITY
D21A-8E0: 0.50 m3 0.75 yd
3
D21P-8E0: 0.68 m3 0.89 yd
3
CRAWLER DOZER
D21A/P-8E0 0
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Optional shoes
Model Type of shoe *Additional weight Ground contact area
*Additional ground
pressure (tractor)
340 mm 13.4" single- +32 kg 11460 cm
2
-0.03 kg/cm
2
grouser shoe +71 lb 1,780 sq.in -0.43 psi -2.9 kPa
300 mm 11.8" single- -30 kg 10110 cm
2
0
D21A-8E0
grouser shoe with hole -66 lb 1,570 sq.in
300 mm 11.8" triple- +81 kg 10110 cm
2
+0.01 kg/cm
2
grouser shoe with hole +179 lb 1,570 sq.in +0.14 psi + 1.0 kPa
300 mm 11.8" flat +8 kg 10110 cm
2
0
shoe with hole +18 lb 1,570 sq.in
510 mm 20.1" single- -73 kg 17190 cm
2
0
D21P-8E0
grouser shoe -161 lb 2,664 sq.in
300 mm 11.8" flat -250 kg 10110 cm
2
+0.12 kg/cm
2
shoe with hole -551 lb 1,570 sq.in +1.7 psi + 1.8 kPa
*Addition to tractor.
OPTIONAL EQUIPMENT
*ROPS cab and ROPS canopy meet ISO 3471, SAE J/ISO 3471 ROPS standards.
STANDARD EQUIPMENT
●
300 mm 11.8" single-grouser shoes (D21A-8E0),
510 mm 20.1" circular-arc shoes (D21P-8E0)
● Hydraulic track adjusters
● 12 V, 40 A alternator
● 12 V, 2.3 kW electric starting motor
● End track guiding guards
● Inching pedal
● Dry-type, interconnected steering clutches
and brakes
● In-line radiator cores
● Dry-type air cleaner with automatic dust
evacuator and dust indicator lamp
● 12 V, 64 Ah (5 hrs rate capacity) batteries
● 5-roller track frames
● Lighting system
(including 2 front and 1 rear lights)
● Blower fan
● Muffler
● Adjustable operator's seat
● Crankcase guard
● Single-lever steering
● Single-lever hydraulic control
CEN00305-00 Materials and specifications are subject to change without notice.
is a trademark of Komatsu Ltd. Japan.
www.Komatsu.com
Printed in Japan 200801 IP.As(10)
ROPS cab* (except machines for USA)
● Front pull hook
● Swing drawbar
● Hitch type drawbar
● Pre-cleaner
● Perforated radiator mask
● F3-R3 Transmission
● Oil-suspension seat
● Track-roller guards, full length
● Lubricated track links
● Backup alarm
● Vandalism protection locks
● Tool kit and ordinary spare parts
ROPS canopy*
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UNDERCARRIAGE
Suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rigid type
Track roller frame. . . . . . . . . . . . . Box-section, high-tensile-strength
steel construction.
Rollers and idlers . . . . . . . . . . . . Lubricated idlers, track and carrier
rollers are sealed with floating seals.
Number of track rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 each
Number of carrier rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 each
Track shoes. . . . . . . . . . . . . . . . . Single-grouser shoes (D21A-8E0)
Circular-arc swamp shoes (D21P-8E0)
Unique dust seals prevent entry of dust into pin-to-bushing clearances
for extended service. Track tension is easily adjusted with a grease gun.
D21A-8E0 D21P-8E0
No. of shoes 37 37
Grouser height 39 mm 1.5" Shoe height - 70 mm 2.8"
Shoe width (standard) 300 mm 11.8" 510 mm 20.1"
Ground contact area 10110 cm
2
17190 cm
2
1,570 sq.in 2,664 sq.in
Ground pressure 30.4 kPa 19.6 kPa
(tractor) 0.31 kg/cm
2
0.20 kg/cm
2
4.41 psi 2.84 psi
COOLANT AND LUBRICANT
CAPACITY (REFILLING)
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 ltr. 2.6 U.S. gal
Fuel tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 ltr. 15.9 U.S. gal
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6 ltr. 1.7 U.S. gal
Damper case . . . . . . . . . . . . . . . . . . . . . . . . . 0.7 ltr. 0.2 U.S. gal
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . 11 ltr. 2.9 U.S. gal
Bevel gear case . . . . . . . . . . . . . . . . . . . . . . . 13 ltr. 3.4 U.S. gal
Final drive (each side)(D21A-8E0) . . . . . . . . . . 6 ltr. 1.6 U.S. gal
Final drive (each side)(D21P-8E0) . . . . . . . . . . 8 ltr. 2.1 U.S. gal
Hydraulic tank . . . . . . . . . . . . . . . . . . . . . . . . . 21 ltr. 5.5 U.S. gal
OPERATING WEIGHT (APPROXIMATE)
Tractor weight:
Including rated capacity of lubricant, coolant, full fuel tank, operator
and standard equipment.
D21A-8E0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3160 kg 6,970 lb
D21P-8E0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3520 kg 7,760 lb
Operating weight:
Including power-angle-tiltdozer, operator, standard equipment, rated
capacity of lubricant, coolant and full fuel tank
D21A-8E0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3710 kg 8,180 lb
D21P-8E0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4100 kg 9,040 lb
HYDRAULIC SYSTEM
Hydraulic control unit: Gear-type hydraulic pump mounted on rear of
engine with capacity (discharge flow) of 59 ltr. 15.6 U.S. gal/min. at rated
engine RPM. Relief valve setting 155 kg/cm22,200 psi 15.2 MPa
Control valves:
Three control valves for power-angle-tiltdozer
Positions: Blade lift . . . . . . . . . . . . . . . . Raise, hold, lower and float
Blade angle . . . . . . . . . . . . . . . . . . . . Left, hold and right
Blade tilt . . . . . . . . . . . . . . . . . . . . . . . Left, hold and right
Hydraulic cylinders: Double-acting, piston type
Number of cylinders Bore
Blade lift 2 70 mm 2.76"
Blade tilt 1 80 mm 3.15"
Blade angling 2 70 mm 2.76"
ENGINE
Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Komatsu 4D94LE-2
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water-cooled, diesel
Aspiration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Naturally aspirated
Number of cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 mm 3.70"
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 mm 4.33"
Piston displacement . . . . . . . . . . . . . . . . . . . . . . . . 3.053 ltr 186 in
3
Net flywheel horsepower:
SAE J1349 . . . . . . . . . . . . . . . . . . 32.4 kW 43.4 HP @ 2450 rpm
DIN 6270 . . . . . . . . . . . . . . . . . . . . 32.4 kW 44 PS @ 2450 rpm
Net maximum torque . . . . 174 Nm 17.8 kg/m 128 ft.lb @ 1300 rpm
Governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . All-speed, mechanical
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Full-flow
Direct injection fuel system with mechanical all-speed governor.
Pump driven forced-lubrication. Dry-type air cleaner with automatic
dust evacuator for longer element service and dust indicator lamp
for simplified maintenance. All the filters are spin-on type for easy
element replacement. Electrical 12-volt starting system. Automatic
air bleeding is just by turning the starting motor.
DAMPER
Wet-type damper, with built-in torsion and friction springs, absorbs
engine torque vibrations as well as stress from external impacts.
HYDROSHIFT TRANSMISSION
The unique Komatsu HYDROSHIFT transmission with planetary
gears is hydraulically-controlled and force-lubricated. Efficient power
flow and simplified direction and speed changes (2 forward and 2
reverse).
Travel speed Forward Rated drawbar pull Reverse
1st 2.6 km/h 3410 kg 3.3 km/h
1.6 MPH 7,520 lb/33.4 kN 2.1 MPH
2nd 4.4 km/h 1890 kg 5.6 km/h
2.7 MPH 4,170 lb/18.5 kN 3.5 MPH
Max. drawbar pull . . . . . . . . . 4520 kg 9,970 lb/44.3 kN (D21A-8E0)
4480 kg 9,880 lb/43.9 kN (D21P-8E0)
STEERING
Single steering lever controls all direction movement. Dry, multipledisc steering clutches are PPC controlled and interconnected with
dry, contracting-band, steering brakes to allow easy, light-touch
steering/braking actions. A PPC valve built into the steering circuit
facilitates smooth, shockless steering control. Inching pedal assures
smooth, easy starting and stopping, precise inching approaches to
obstacles and impact digging.
FINAL DRIVE
Spur gear, single-reduction final drives.
C RAWLER D OZER
D21A/P-8E0
SPECIFICATIONS
Page 6
D21A-8E0 (equipped with power-angle-tiltdozer)
Ground clearance . . . . . . . . .295 11.6"
D21P-8E0 (equipped with power-angle-tiltdozer)
Ground clearance . . . . . . . . .355 1'2"
1785
5'10"
39
1.5"
2315
7'7"
790
2'7"
385
1'3"
1685
5'6"
2890
9'6"
GL
3250
10'8"
2170
7'1"
250
9.8"
1310
4'4"
2560
8'5"
1810
5'11"
70
2.8"
2335
7'8"
850
2'9"
325
1'1"
2890
9'6"
GL
3260
10'8"
1490
4'11"
280
11.0"
1685
5'6"
Use of high-tensile-strength steel in moldboard extended service. Hydraulic hoses for blade angling and tilting are covered with
steel plates and protected from damage.
Power-angle-tiltdozer
Overall Blade capacity Blade Max. lift Max. drop Max. tilt Additional weight Additional
Length
SAE *LH
2
length x height above below adjustment
Blade
Hydraulic
ground
With dozer ground ground control unit pressure
3250 mm 0.57 m
3
0.76 m32170 mm x 590 mm 790 mm 385 mm 250 mm 480 kg 70 kg 0.054 kg/cm
2
D21A-8E0 0.77 psi
10'8" 0.75 cu.yd 0.99 cu.yd 7'1" x 1'11" 2'7" 1'3" 9.8" 1,060 lb 150 lb 5.3 kPa
3260 mm 0.68 m
3
0.89 m32560 mm x 590 mm 850 mm 325 mm 280 mm 510 kg 70 kg 0.03 kg/cm
2
D21P-8E0 0.43 psi
10'8" 0.89 cu.yd 1.16 cu.yd 8'5" x 1'11" 2'9" 1'1" 11" 1,120 lb 150 lb 2.94 kPa
*(L: Blade length) x (H: Blade height)
2
DOZER EQUIPMENT
DIMENSIONS
Unit: mm ft.in
CRAWLER DOZER
D21A/P-8E0 0
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