Machine models

Komatsu D31 variants: engine, blade and control identification

D31P-18 travel faults require the correct control layout

Komatsu's original D31-18 manual separates the dozer power-train circuits from the shovel versions. The illustrated dozer drive passes through a damper and universal joint into the HYDROSHIFT transmission, then through the bevel gear, steering clutches and final drives. A failure to travel is not automatically a failed engine-to-transmission coupling.

The transmission control description connects the gear lever to the speed and direction spools. The inching pedal operates another spool and is linked with the brake. An incompletely returning pedal or incorrect linkage adjustment therefore belongs in a travel complaint's investigation; the parts to inspect differ from a hydrostatic crawler's controls.

The implement chapters distinguish the D31P-18A power-angle-tilt arrangement from the straight-tilt equipment on D31P, PL and PLL versions. Photograph the blade linkage before ordering a valve or cylinder. Matching horsepower does not establish matching implement plumbing.

Source: Komatsu SEBM01141805, reproduced manual extract, control and equipment chapters.

D31-17, D31-18 and D31-20 filter entries depend on the engine

Baldwin's application catalogue splits D31-20 machines into separate engine groups. The group using the S4D102E has different oil, fuel and air-filter references from the group using the six-cylinder 6D95L. A filter kit described only as fitting a D31-20 leaves that distinction unresolved.

The D31-18 group has its own entry, while D31P-18A engine suffixes appear separately. Baldwin also distinguishes D31P-17A from the broader D31-17 group. Check the engine plate, the fitted filter's original-equipment number and the catalogue's application heading together.

One matching hydraulic-filter reference does not prove that the rest of a kit fits. The catalogue itself instructs readers to check the original-equipment numbers shown beside its replacements.

Source: Baldwin Off-Highway Applications, printed pages1055–1056.

Japanese D31A-20E records identify an exact model and engine

Japan's construction-equipment emissions list pairs the D31A-20E with the S4D102E-1-A engine. The adjacent D31AM-20E and wet-ground D31P-20E entries are separate machines, despite sharing that engine designation. Use the complete suffix when comparing an imported tractor with these records.

The environment ministry's small-production approval register also names D31A-20E under a specific approval and vehicle type. That approval date is not the manufacture date of an individual dozer. Nor does an entry in a Japanese register establish U.S. import eligibility.

Keep the machine's identity documents with the engine and chassis photographs.

Sources: MLIT construction-equipment emissions list; Japan environment ministry small-production approval register.

Earlier reference entries and original manufacturer corrections
Model and field	Earlier entry	Manufacturer figure and scope	Source
D31P-18 Transmission Type	DPS	Komatsu HYDROSHIFT;originalSEBM01141805 D31-18 dozer power-train description	Original document

Entries in this reference
Listing-entry count
12

Short answer

Komatsu D31 variants: engine, blade and control identification: crawler dozers.

Selected configuration figures
Configuration	Documented field and quantity
D31A-20E	Gross Power 71 hp Operating Weight 13,801 lb
D31P-17A	Gross Power 68 hp Operating Weight 14,992 lb
D31P-18	Gross Power 71 hp Operating Weight 14,771 lb
D31P-18A	Gross Power 71 hp Operating Weight 14,992 lb
D31P-20AE	Gross Power 71 hp Operating Weight 15,278 lb
D31P-20BE	Gross Power 71 hp Operating Weight 15,278 lb
D31PG-20E	Gross Power 71 hp Operating Weight 15,521 lb
D31PL-17	Gross Power 68 hp Operating Weight 15,543 lb
D31PL-18	Gross Power 71 hp Operating Weight 15,543 lb
D31PL-20E	Gross Power 71 hp Operating Weight 15,851 lb
D31PLL-17	Gross Power 68 hp Operating Weight 16,645 lb
D31PLL-18	Gross Power 71 hp Operating Weight 16,645 lb

D31A-20E to D31PLL-18 specification matrix — Listing labels reported by the source
Publisher name	Source guide	Listing-entry count	Labels named by the source
Komatsu	D31A-20E to D31PLL-18	12	D31A-20E, D31P-17A, D31P-18, D31P-18A, D31P-20AE, D31P-20BE, and 6 more

Dimensions and weight
Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Length W/ Blade	12.6 ft	12.93 ft	12.64 ft	12.93 ft	12.93 ft	12.93 ft	12.9 ft	12.72 ft	12.72 ft	12.72 ft	13.93 ft	14.11 ft
Width Over Tracks	5.88 ft	7.39 ft	6.73 ft	7.39 ft	7.39 ft	7.39 ft	7.39 ft	9.68 ft	9.68 ft	9.68 ft	9.68 ft	9.68 ft
Height To Top Of Cab	8.91 ft	8.88 ft	8.96 ft	8.96 ft	8.98 ft	8.98 ft	8.95 ft	8.88 ft	8.96 ft	8.98 ft	8.88 ft	8.96 ft
Length Of Track On Ground	6.17 ft	7.17 ft	7.19 ft	7.17 ft	7.17 ft	7.17 ft	7.17 ft	7.17 ft	7.17 ft	7.17 ft	8.44 ft	8.44 ft
Ground Clearance	1.04 ft	1.25 ft	1.25 ft	1.25 ft	1.25 ft	1.25 ft	1.22 ft	1.25 ft	1.25 ft	1.25 ft	1.25 ft	1.25 ft

Specification	D31A-20E	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-18
Length W/O Blade	9.55 ft	9.95 ft	9.95 ft	9.95 ft	9.95 ft	9.88 ft	9.95 ft	9.95 ft	9.95 ft	11.19 ft

Undercarriage
Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Track Gauge	4.76 ft	5.42 ft	4.76 ft	5.42 ft	5.42 ft	5.42 ft	5.42 ft	6.24 ft	6.24 ft	6.24 ft	6.24 ft	6.24 ft
Standard Shoe Size	13 in	23.63 in	23.63 in	23.63 in	23.63 in	23.63 in	23.63 in	41.34 in	41.34 in	41.34 in	41.34 in	41.34 in
Number Of Track Rollers Per Side	5	6	6	6	6	6	6	6	6	6	8	8

Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PLL-17	D31PLL-18
Track Pitch	6.07 in	6.07 in	6.07 in	6.07 in	6.07 in	6.07 in	6.3 in	6.07 in	6.07 in	6.07 in	6.07 in

Specification	D31P-17A	D31P-18	D31P-18A	D31PL-17	D31PL-18	D31PLL-17	D31PLL-18
Number Of Shoes Per Side	41	41	41	41	41	46	46

Specification	D31PLL-17	D31PLL-18
Number Of Carrier Rollers Per Side	2	2

Engine
Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Number Of Cylinders	4	4	6	6	4	4	4	4	6	4	4	6
Engine Model	S4D102E-1-A	4D105-5	6D95L	6D95L	S4D102E-1-A	S4D102E-1-A	S4D102E-1-A	4D105-5	6D95L-1	S4D102E-1-A	4D105-5	6D95L-1
Gross Power	71 hp	68 hp	71 hp	71 hp	71 hp	71 hp	71 hp	68 hp	71 hp	71 hp	68 hp	71 hp
Power Measured @	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm	2,350 rpm
Displacement	239.3 cu in	264.3 cu in	298.5 cu in	298.5 cu in	239.3 cu in	239.3 cu in	239.3 cu in	264.3 cu in	298.5 cu in	239.3 cu in	264.3 cu in	298.5 cu in

Operational
Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Operating Weight	13,801 lb	14,992 lb	14,771 lb	14,992 lb	15,278 lb	15,278 lb	15,521 lb	15,543 lb	15,543 lb	15,851 lb	16,645 lb	16,645 lb

Transmission and speeds
Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Transmission Type	HS	HS	Komatsu HYDROSHIFT;originalSEBM01141805 D31-18 dozer power-train description	HS	HS	HS	HS	HS	HS	HS	HS	HS
Number Of Forward Gears	3	3	3	3	3	3	3	3	3	3	3	3
Number Of Reverse Gears	3	3	3	3	3	3	3	3	3	3	3	3

Standard Blade
Specification	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Blade width	8 ft	9.5 ft	8.1 ft	9.5 ft	9.5 ft	9.5 ft	9.5 ft	11.3 ft	11.3 ft	11.3 ft	11.3 ft	11.3 ft
Blade height	33.1 in	29.4 in	31.2 in	31.2 in	31.2 in	31.2 in	31.2 in	21.5 in	21.5 in	21.5 in	21.5 in	21.5 in

Variants — Source comparison annotation
Source guide	Differing-field count reported
D31A-20E to D31PLL-18	20

Ratios
Figure	D31A-20E	D31P-17A	D31P-18	D31P-18A	D31P-20AE	D31P-20BE	D31PG-20E	D31PL-17	D31PL-18	D31PL-20E	D31PLL-17	D31PLL-18
Engine horsepower per 1,000 lb of weight	5.1	4.5	4.8	4.7	4.6	4.6	4.6	4.4	4.6	4.5	4.1	4.3

D31A-20E to D31PLL-18: owner reports

Related account: “Steering clutches and transmission on project machines”: D31A-17, D31Q-17, and D31S-17.

D31A-20E to D31PLL-18: forum references — Forum-title search
Forum index	Equipment class queried	Names in the search	Matching titles
Heavy Equipment Forums	crawler dozer	Komatsu and the D31A, D31P, D31 line that the D31A-20E, D31P-17A, D31P-18, D31P-18A belongs to (no title names the exact model)	181

Topics named by those titles
Title topic	Titles
transmission and drive	20
brakes and steering	13
starting and cranking	6

Topic in the title	Threads	Share of matching threads
transmission and drive	20	11%
brakes and steering	13	7%
starting and cranking	6	3%
emissions	4	2%
hydraulics	4	2%

Any Information On A Komatsu Winch Coupled To A Komatsu D31 Dozer Any Informationat All (Heavy Equipment Forums, 2026-08-23)
Komatsu D31a 16 (Heavy Equipment Forums, 2026-07-07)
Komatsu D31p 18 (Heavy Equipment Forums, 2026-04-20)
1985 Komatsu D31a 17 (Heavy Equipment Forums, 2025-12-20)

Used market for the D31A-20E to D31PLL-18 — Dated first-page listing snapshot
Observation date	Listing source	Equipment search	Listings
2026-09-24	MachineryTrader	Komatsu crawler dozer	1

Model	Listed	Model years	Lowest asking	Highest asking	Median asking	Median hours
D31P-18	1	1991	None shown	None shown	None shown	None shown

D31A-20E to D31PLL-18: 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 crawler dozer D31A-20E, D31P-17A, D31P-18, D31P-18A	No matching recall in this search

Sources for this page
Evidence class	Document, classification and recorded date
Reference site	Reference site: Komatsu D31A-20E — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31P-17A — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31P-18 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31P-18A — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31P-20AE — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31P-20BE — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31PG-20E — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31PL-17 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31PL-18 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31PL-20E — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31PLL-17 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu D31PLL-18 — RitchieSpecs. Observed 2026-09-24.
Forum threads	Forum threads: Heavy Equipment Forums thread index for Komatsu D31A-20E to D31PLL-18 — Heavy Equipment Forums. Observed 2026-09-24.
Used-market listings	Used-market listings: MachineryTrader listings for Komatsu D31P-18 — 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.