Machine models

Komatsu Hm300-1 to HM400-2 specifications

Entries in this reference
Listing-entry count
4

Short answer

Komatsu Hm300-1 to HM400-2: articulated dump trucks.

Selected configuration figures
Configuration	Documented field and quantity
Hm300-1	Gross Power 335.3 hp Overall Length 33.13 ft
HM350-1	Gross Power 399.7 hp Overall Length 36.18 ft
Hm400-1	Gross Power 443.9 hp Overall Length 36.18 ft
HM400-2	Gross Power 453 hp Overall Length 37.08 ft

Hm300-1 to HM400-2 specification matrix — Listing labels reported by the source
Publisher name	Source guide	Listing-entry count	Labels named by the source
Komatsu	Hm300-1 to HM400-2	4	Hm300-1, HM350-1, Hm400-1, and HM400-2

Dimensions and weight
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Overall Length	33.13 ft	36.18 ft	36.18 ft	37.08 ft
Overall Height	11.49 ft	12.14 ft	12.14 ft	12.17 ft
Wheelbase	16.26 ft	17.51 ft	17.51 ft	17.5 ft
Ground Clearance	1.68 ft	2.04 ft	2.04 ft	2 ft
Dump Height	21.15 ft	23.4 ft	23.4 ft	23.42 ft
Dump Ground Clearance	1.99 ft	2.37 ft	2.37 ft	2.33 ft

Specification	HM350-1	Hm400-1	HM400-2
Overall Width	11.32 ft	11.32 ft	11.33 ft

Dump
Specification	Hm300-1	Hm400-1	HM400-2
Dump Angle	70 degrees	70 degrees	70 degrees

Specification	Hm300-1	HM400-2
Rated Payload	60,186 lb	80,634 lb

Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Capacity - Struck	16.88 yd3	19.1 yd3	21.59 yd3	21.6 yd3
Raise Time	12 sec	12 sec	12 sec	12 sec
Capacity - Heaped	21.72 yd3	25.9 yd3	29.17 yd3	29.2 yd3

Engine
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Number Of Cylinders	6	6	6	6
Engine Model	SAA6D125E-3	SAA6D140E-3	SAA6D140E-3	SAA6D140E-5
Gross Power	335.3 hp	399.7 hp	443.9 hp	453 hp
Net Power	324.6 hp	388.9 hp	430.5 hp	438 hp
Aspiration	Turbocharged	Turbocharged	Turbocharged	Turbocharged
Displacement	673.8 cu in	930.1 cu in	927.6 cu in	928 cu in

Specification	Hm300-1	HM350-1	Hm400-1
Max Torque	1,180 lb-ft	1,438 lb-ft	1,468 lb-ft

Specification	HM350-1	Hm400-1	HM400-2
Power Measured @	2,000 rpm	2,000 rpm	2,100 rpm

Operational
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Fuel Capacity	101 gal	130.8 gal	130.8 gal	130.8 gal
Hydraulic System Fluid Capacity	31.8 gal	47.6 gal	47.6 gal	47.6 gal
Engine Oil Capacity	9.3 gal	13.8 gal	13.8 gal	13.2 gal
Tire Size	23.5R25	26.5 R25	29.5 R25	29.5R25

Specification	Hm300-1	HM350-1	Hm400-1
Transmission Fluid Capacity	20.5 gal	30.4 gal	30.4 gal

Transmission and speeds
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Transmission Type	full-automatic	full-automatic	full-automatic	full automatic, countershaft type
Number Of Forward Gears	6	6	6	6
Number Of Reverse Gears	2	2	2	2
Max Speed	36.7 mph	35.5 mph	36.5 mph	36.4 mph

Weights
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Center Axle - Empty	11012.1 %	13950.7 %	14832.6 %	16316 %
Front Axle - Empty	28,175 lb	34,798 lb	36,849 lb	39,430 lb
Rear Axle - Empty	10,417 lb	13,951 lb	14,833 lb	15,815 lb
Front Axle - Loaded	32766.8 %	40758.6 %	41789.9 %	44138 %
Center Axle - Loaded	39254.2 %	46657.8 %	52678.9 %	54335 %
Rear Axle - Loaded	37,935 lb	46,658 lb	52,679 lb	53,727 lb
Total Empty	49,604 lb	62,700 lb	66,514 lb	71,560 lb
Total Loaded	109,956 lb	134,074 lb	147,148 lb	152,200 lb

Variants — Source comparison annotation
Source guide	Differing-field count reported
Hm300-1 to HM400-2	32

Ratios
Figure	Hm300-1	HM350-1	Hm400-1	HM400-2
Engine horsepower per 1,000 lb of weight	6.5	6.2	6.5	6.1
Fuel tank per engine horsepower	0.31 gal	0.34 gal	0.30 gal	0.30 gal

Figure	Hm300-1	HM400-2
Rated payload per cubic yard of heaped body	2,771 lb	2,761 lb

Hm300-1 to HM400-2: owner reports

Sources: 3 forum discussions about the Komatsu HM400 articulated trucks (HM400-1, HM400-3); heavyequipmentforums.com.

Stuck in low gear, controller errors and transmission rebuild effort. An HM400-1 that would not shift out of low, where a reply named three usual culprits including the dump body not seated and the retarder not fully released, an HM400-3 with hoist retarder controller errors that would not clear after months of sensor and wiring changes, and a question about the labour to rebuild an HM400-1 transmission, described by a reply as a great deal of work to remove. Threads read: 1, 2, 3.

Hm300-1 to HM400-2: forum references — Forum-title search
Forum index	Equipment class queried	Names in the search	Matching titles
Heavy Equipment Forums	articulated dump truck	Komatsu and the HM300, HM350, HM400 line that the Hm300-1, HM350-1, Hm400-1, HM400-2 belongs to (no title names the exact model). That is too few titles to say what owners mostly ask about, so the most recent are listed instead	10

Komatsu Hm 300 2 Articulated Truck With Codes (Heavy Equipment Forums, 2026-07-30)
Komatsu Hm400 (Heavy Equipment Forums, 2025-09-03)
Komatsu Hm350 Cranks But No Start (Heavy Equipment Forums, 2025-01-06)
Komatsu Artic Hm 400 (Heavy Equipment Forums, 2021-02-04)

Used market for the Hm300-1 to HM400-2 — Dated first-page listing snapshot
Observation date	Listing source	Equipment search	Listings
2026-09-24	MachineryTrader	Komatsu articulated dump truck	20

Model	Listed	Model years	Lowest asking	Highest asking	Median asking	Median hours
Hm400-1	5	2005 to 2011	$25,825	$82,522	$43,259	8,157
HM400-2	15	2006 to 2012	$41,561	$137,222	$109,074	None shown

Hm300-1 to HM400-2: recall reference — Dated CPSC search
Search date	Database	Names queried	Search result
2026-09-24	U.S. Consumer Product Safety Commission	Komatsu together with the articulated dump truck Hm300-1, HM350-1, Hm400-1, HM400-2	No matching recall in this search

Sources for this page
Evidence class	Document, classification and recorded date
Reference site	Reference site: Komatsu Hm300-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu HM350-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu Hm400-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu HM400-2 — RitchieSpecs. Observed 2026-09-24.
Forum threads	Forum threads: Heavy Equipment Forums thread index for Komatsu Hm300-1 to HM400-2 — Heavy Equipment Forums. Observed 2026-09-24.
Forum threads	Forum threads: Forum threads read for the Komatsu HM400 articulated trucks (HM400-1, HM400-3) — Heavyequipmentforums. Observed 2026-09-24.
Used-market listings	Used-market listings: MachineryTrader listings for Komatsu Hm400-1 — MachineryTrader. Observed 2026-09-24.
Federal agency data	Federal agency data: Recall database search for Komatsu — U.S. Consumer Product Safety Commission. Observed 2026-09-24.

Recorded observations — Forum-title snapshot
Observation field	Recorded value
Title count	10
Forum indexes	Heavy Equipment Forums
Search wording	the Hm300-1 to HM400-2 articulated dump truck
Latest title quoted by the reference	Komatsu Hm 300 2 Articulated Truck With Codes

Komatsu Hm300-1 to HM400-2: Configuration records

Hm300-1

Specification	Source figure
Dimensions and weight
Overall Length	33.13 ft
Overall Height	11.49 ft
Wheelbase	16.26 ft
Ground Clearance	1.68 ft
Dump Height	21.15 ft
Dump Ground Clearance	1.99 ft
Dump
Capacity - Heaped	21.72 yd3
Rated Payload	60,186 lb
Dump Angle	70 degrees
Capacity - Struck	16.88 yd3
Raise Time	12 sec
Engine
Number Of Cylinders	6
Engine Model	SAA6D125E-3
Gross Power	335.3 hp
Net Power	324.6 hp
Displacement	673.8 cu in
Max Torque	1,180 lb-ft
Aspiration	Turbocharged
Operational
Fuel Capacity	101 gal
Tire Size	23.5R25
Hydraulic System Fluid Capacity	31.8 gal
Engine Oil Capacity	9.3 gal
Transmission Fluid Capacity	20.5 gal
Transmission and speeds
Number Of Forward Gears	6
Max Speed	36.7 mph
Transmission Type	full-automatic
Number Of Reverse Gears	2
Weights
Front Axle - Empty	28,175 lb
Rear Axle - Empty	10,417 lb
Front Axle - Loaded	32766.8 %
Rear Axle - Loaded	37,935 lb
Total Empty	49,604 lb
Total Loaded	109,956 lb
Center Axle - Empty	11012.1 %
Center Axle - Loaded	39254.2 %

Source

HM350-1

Specification	Source figure
Dimensions and weight
Overall Length	36.18 ft
Overall Width	11.32 ft
Overall Height	12.14 ft
Wheelbase	17.51 ft
Ground Clearance	2.04 ft
Dump Height	23.4 ft
Dump Ground Clearance	2.37 ft
Dump
Capacity - Heaped	25.9 yd3
Capacity - Struck	19.1 yd3
Raise Time	12 sec
Engine
Number Of Cylinders	6
Engine Model	SAA6D140E-3
Gross Power	399.7 hp
Net Power	388.9 hp
Power Measured @	2,000 rpm
Displacement	930.1 cu in
Max Torque	1,438 lb-ft
Aspiration	Turbocharged
Operational
Fuel Capacity	130.8 gal
Tire Size	26.5 R25
Hydraulic System Fluid Capacity	47.6 gal
Engine Oil Capacity	13.8 gal
Transmission Fluid Capacity	30.4 gal
Transmission and speeds
Number Of Forward Gears	6
Max Speed	35.5 mph
Transmission Type	full-automatic
Number Of Reverse Gears	2
Weights
Front Axle - Empty	34,798 lb
Rear Axle - Empty	13,951 lb
Front Axle - Loaded	40758.6 %
Rear Axle - Loaded	46,658 lb
Total Empty	62,700 lb
Total Loaded	134,074 lb
Center Axle - Empty	13950.7 %
Center Axle - Loaded	46657.8 %

Source

Hm400-1

Specification	Source figure
Dimensions and weight
Overall Length	36.18 ft
Overall Width	11.32 ft
Overall Height	12.14 ft
Wheelbase	17.51 ft
Ground Clearance	2.04 ft
Dump Height	23.4 ft
Dump Ground Clearance	2.37 ft
Dump
Capacity - Heaped	29.17 yd3
Dump Angle	70 degrees
Capacity - Struck	21.59 yd3
Raise Time	12 sec
Engine
Number Of Cylinders	6
Engine Model	SAA6D140E-3
Gross Power	443.9 hp
Net Power	430.5 hp
Power Measured @	2,000 rpm
Displacement	927.6 cu in
Max Torque	1,468 lb-ft
Aspiration	Turbocharged
Operational
Fuel Capacity	130.8 gal
Tire Size	29.5 R25
Hydraulic System Fluid Capacity	47.6 gal
Engine Oil Capacity	13.8 gal
Transmission Fluid Capacity	30.4 gal
Transmission and speeds
Number Of Forward Gears	6
Max Speed	36.5 mph
Transmission Type	full-automatic
Number Of Reverse Gears	2
Weights
Front Axle - Empty	36,849 lb
Rear Axle - Empty	14,833 lb
Front Axle - Loaded	41789.9 %
Rear Axle - Loaded	52,679 lb
Total Empty	66,514 lb
Total Loaded	147,148 lb
Center Axle - Empty	14832.6 %
Center Axle - Loaded	52678.9 %

Source

HM400-2

Specification	Source figure
Dimensions and weight
Overall Length	37.08 ft
Overall Width	11.33 ft
Overall Height	12.17 ft
Wheelbase	17.5 ft
Ground Clearance	2 ft
Dump Height	23.42 ft
Dump Ground Clearance	2.33 ft
Dump
Capacity - Heaped	29.2 yd3
Rated Payload	80,634 lb
Dump Angle	70 degrees
Capacity - Struck	21.6 yd3
Raise Time	12 sec
Engine
Number Of Cylinders	6
Engine Model	SAA6D140E-5
Gross Power	453 hp
Net Power	438 hp
Power Measured @	2,100 rpm
Displacement	928 cu in
Aspiration	Turbocharged
Operational
Fuel Capacity	130.8 gal
Tire Size	29.5R25
Hydraulic System Fluid Capacity	47.6 gal
Engine Oil Capacity	13.2 gal
Transmission and speeds
Number Of Forward Gears	6
Max Speed	36.4 mph
Transmission Type	full automatic, countershaft type
Number Of Reverse Gears	2
Weights
Front Axle - Empty	39,430 lb
Rear Axle - Empty	15,815 lb
Front Axle - Loaded	44138 %
Rear Axle - Loaded	53,727 lb
Total Empty	71,560 lb
Total Loaded	152,200 lb
Center Axle - Empty	16316 %
Center Axle - Loaded	54335 %

Source

Compare Komatsu Hm300-1, HM350-1, Hm400-1, HM400-2

Dimensions and weight
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Overall Length	33.13 ft	36.18 ft	36.18 ft	37.08 ft
Overall Height	11.49 ft	12.14 ft	12.14 ft	12.17 ft
Wheelbase	16.26 ft	17.51 ft	17.51 ft	17.5 ft
Ground Clearance	1.68 ft	2.04 ft	2.04 ft	2 ft
Dump Height	21.15 ft	23.4 ft	23.4 ft	23.42 ft
Dump Ground Clearance	1.99 ft	2.37 ft	2.37 ft	2.33 ft

Dump
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Capacity - Struck	16.88 yd3	19.1 yd3	21.59 yd3	21.6 yd3
Raise Time	12 sec	12 sec	12 sec	12 sec
Capacity - Heaped	21.72 yd3	25.9 yd3	29.17 yd3	29.2 yd3

Engine
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Number Of Cylinders	6	6	6	6
Engine Model	SAA6D125E-3	SAA6D140E-3	SAA6D140E-3	SAA6D140E-5
Gross Power	335.3 hp	399.7 hp	443.9 hp	453 hp
Net Power	324.6 hp	388.9 hp	430.5 hp	438 hp
Aspiration	Turbocharged	Turbocharged	Turbocharged	Turbocharged
Displacement	673.8 cu in	930.1 cu in	927.6 cu in	928 cu in

Operational
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Fuel Capacity	101 gal	130.8 gal	130.8 gal	130.8 gal
Hydraulic System Fluid Capacity	31.8 gal	47.6 gal	47.6 gal	47.6 gal
Engine Oil Capacity	9.3 gal	13.8 gal	13.8 gal	13.2 gal
Tire Size	23.5R25	26.5 R25	29.5 R25	29.5R25

Transmission and speeds
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Transmission Type	full-automatic	full-automatic	full-automatic	full automatic, countershaft type
Number Of Forward Gears	6	6	6	6
Number Of Reverse Gears	2	2	2	2
Max Speed	36.7 mph	35.5 mph	36.5 mph	36.4 mph

Weights
Specification	Hm300-1	HM350-1	Hm400-1	HM400-2
Center Axle - Empty	11012.1 %	13950.7 %	14832.6 %	16316 %
Front Axle - Empty	28,175 lb	34,798 lb	36,849 lb	39,430 lb
Rear Axle - Empty	10,417 lb	13,951 lb	14,833 lb	15,815 lb
Front Axle - Loaded	32766.8 %	40758.6 %	41789.9 %	44138 %
Center Axle - Loaded	39254.2 %	46657.8 %	52678.9 %	54335 %
Rear Axle - Loaded	37,935 lb	46,658 lb	52,679 lb	53,727 lb
Total Empty	49,604 lb	62,700 lb	66,514 lb	71,560 lb
Total Loaded	109,956 lb	134,074 lb	147,148 lb	152,200 lb

More in Komatsu: HM300-5, HA250-3/HA270-3, HM300-2/HM400-3M0.

Komatsu Hm300-1 to HM400-2 specifications

Hm300-1 to HM400-2: owner reports

Sources for this page

Komatsu Hm300-1 to HM400-2: Configuration records