Machine models

Komatsu GD305A-3 and 11 related models specifications

Entries in this reference
Listing-entry count
12

Short answer

Komatsu GD305A-3 and 11 related models: motor graders.

Selected configuration figures
Configuration	Documented field and quantity
GD305A-3	Max Power 100 hp Std Operation Weight - Total 17,593 lb
GD500R-2	Max Power 130 hp Std Operation Weight - Front Axle 6,471 lb
GD510R-1	Max Power 124.8 hp Std Operation Weight - Total 23,590 lb
GD505A-2	Net Power Gear 5-6 130 hp Std Operation Weight - Front Axle 6,526 lb
GD505R-2	Net Power Gear 5-6 130 hp Std Operation Weight - Front Axle 6,614 lb
GD521A-1	Net Power Gear 5-6 135.5 hp Std Operation Weight - Total 23,810 lb
GD511A-1	Net Power Gear 5-6 135.5 hp Std Operation Weight - Total 23,810 lb
GD611A-1	Net Power Gear 5-6 155.6 hp Std Operation Weight - Total 27,558 lb
GD621R-1	Net Power Gear 5-6 155.6 hp Std Operation Weight - Total 27,999 lb
GD623A-1	Net Power Gear 5-6 155.6 hp Std Operation Weight - Total 27,999 lb
GD625A-1	Net Power Gear 5-6 155.6 hp Std Operation Weight - Total 30,203 lb
GD661A-1	Net Power Gear 5-6 179.7 hp Std Operation Weight - Total 29,322 lb

GD305A-3 and 11 related models specification matrix — Listing labels reported by the source
Publisher name	Source guide	Listing-entry count	Labels named by the source
Komatsu	GD305A-3 and 11 related models	12	GD305A-3, GD500R-2, GD510R-1, GD505A-2, GD505R-2, GD521A-1, and 6 more

Dimensions and weight
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Overall Length	22.76 ft	25.99 ft	25.69 ft	25.99 ft	26.51 ft	26.78 ft	25.91 ft	27.5 ft	27.5 ft	27.89 ft	27.89 ft	27.5 ft
Width Over Tires	6.89 ft	7.67 ft	7.86 ft	7.67 ft	7.67 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft
Wheelbase	16.41 ft	18.97 ft	18.97 ft	18.97 ft	18.97 ft	18.97 ft	18.97 ft	19.69 ft	19.69 ft	19.69 ft	19.69 ft	19.69 ft
Tandem Axle Wheelbase	4.38 ft	4.94 ft	5.04 ft	4.94 ft	4.94 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft
Blade Base	6.94 ft	8.34 ft	8.34 ft	8.34 ft	8.34 ft	8.34 ft	8.34 ft	8.54 ft	8.54 ft	8.54 ft	8.54 ft	8.54 ft
Height To Top Of Isomount Cab	8.01 ft	9.77 ft	11.44 ft	9.11 ft	9.77 ft	11.44 ft	11.44 ft	11.44 ft	11.44 ft	11.44 ft	10.85 ft	11.44 ft

Specification	GD500R-2	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Rear Ground Clearance	1.24 ft	1.15 ft	1.15 ft	1.19 ft	1.2 ft	1.17 ft	1.17 ft	1.17 ft	1.17 ft	1.17 ft

Specification	GD500R-2	GD510R-1	GD505A-2	GD505R-2
Front Ground Clearance	1.81 ft	1.2 ft	1.81 ft	1.81 ft

Engine
Specification	GD305A-3	GD510R-1	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Number Of Cylinders	4	6	6	6	6	6	6	6	6
Power Measured @	2,500 rpm	2,500 rpm	2,500 rpm	2,900 rpm	2,500 rpm	2,500 rpm	2,200 rpm	2,200 rpm	2,500 rpm

Specification	GD305A-3	GD500R-2	GD510R-1
Net Power Gear 4-6	100 hp	130 hp	124.8 hp

Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Engine Model	S4D102E	S6D105-1	S6D95L	S6D105-1	S6D105	S6D105	S6D95L	S6D105	S6D105	6D125	6D125	S6D105
Max Power	100 hp	130 hp	124.8 hp	130 hp	130 hp	135.5 hp	135.5 hp	155.6 hp	155.6 hp	155.6 hp	155.6 hp	179.7 hp
Displacement	239.3 cu in	396 cu in	298.5 cu in	396 cu in	396 cu in	396.1 cu in	298.5 cu in	396.1 cu in	396.1 cu in	674.4 cu in	674.4 cu in	396.1 cu in

Specification	GD500R-2
Net Torque Gears 3-4	345 lb-ft

Specification	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Net Power Gear 5-6	130 hp	130 hp	135.5 hp	135.5 hp	155.6 hp	155.6 hp	155.6 hp	155.6 hp	179.7 hp

Specification	GD505A-2
Net Torque Gears 5-6	345 lb-ft
Aspiration	turbocharged

Operational
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Std Operation Weight - Total	17,593 lb	23,149 lb	23,590 lb	23,986 lb	23,656 lb	23,810 lb	23,810 lb	27,558 lb	27,999 lb	27,999 lb	30,203 lb	29,322 lb
Tire Size	front 9.00-20-8PR rear 10.00-20-10PR	13.00-24-8PR (G-2)	13.00-24-8PR	13.00-24-8PR	13.00-24-8 PR	13.00-24-8PR	13.00-24-8PR	13.00-24-10PR	13.00-24-10PR	13.00-24-10PR	13.00-24-10PR	13.00-24-10PR

Specification	GD305A-3	GD510R-1	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Fuel Capacity	34.4 gal	60 gal	60 gal	60 gal	75.3 gal	75.3 gal	75.3 gal	75.3 gal	75.3 gal

Specification	GD500R-2	GD505A-2	GD505R-2
Std Operation Weight - Front Axle	6,471 lb	6,526 lb	6,614 lb
Std Operation Weight - Rear Axle	16,678 lb	17,461 lb	17,042 lb

Steering
Specification	GD305A-3	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD623A-1	GD625A-1	GD661A-1
Articulation Angle	27 degrees	36 degrees	27 degrees	27 degrees	26 degrees	26 degrees	26 degrees	26 degrees

Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Turning Radius	18.7 ft	34.2 ft	34.2 ft	21.7 ft	34.2 ft	21.7 ft	21.7 ft	22.7 ft	34.2 ft	22.7 ft	22 ft	22.7 ft

Transmission and speeds
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Number Of Gears - Forward	4	4	4	6	6	6	6	6	6	6	6	6
Max Speed - Forward	21.5 mph	25.7 mph	26.7 mph	27 mph	27 mph	27.8 mph	27.7 mph	27.8 mph	27.8 mph	28.9 mph	28 mph	27.8 mph
Max Speed - Reverse	15.3 mph	15.9 mph	16.6 mph	28 mph	28 mph	33.9 mph	33.9 mph	33.9 mph	33.9 mph	35.3 mph	34.1 mph	33.9 mph

Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2
Number Of Gears - Reverse	1	4	4	6	6

Specification	GD500R-2	GD505A-2	GD505R-2
Transmission Type	constant mesh	Hydroshift	Hydroshift

Moldboard
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Moldboard Width	10.4 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.1 ft	12.2 ft
Moldboard Height	20.9 in	25.8 in	25.4 in	25.8 in	25.8 in	25.4 in	25.4 in	25.4 in	25.4 in	25.4 in	25.4 in	25.4 in

Specification	GD500R-2	GD505A-2	GD505R-2
Moldboard Thickness	0.8 in	0.8 in	0.8 in
Max Depth Of Cut	19.9 in	19.9 in	19.9 in

Front Axle
Specification	GD500R-2	GD505A-2	GD505R-2
Wheel Lean	20 degrees	20 degrees	20 degrees
Oscillation - Total	30 degrees	30 degrees	30 degrees

Specification	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Ground Clearance	1.9 ft	1.2 ft	1.9 ft	1.9 ft	1.2 ft	1.2 ft	1.2 ft	1.2 ft	1.2 ft	1.2 ft	1.2 ft

Circle
Specification	GD500R-2	GD505A-2	GD505R-2
Max Reach Outside Tires - Left	80.8 in	80.8 in	80.8 in
Max Reach Outside Tires - Right	78.8 in	78.8 in	78.8 in
Max Lift Above Ground	17 in	17 in	17 in

Variants — Source comparison annotation
Source guide	Differing-field count reported
GD305A-3 and 11 related models	40

Ratios
Figure	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Engine horsepower per 1,000 lb of weight	5.7	5.6	5.3	5.4	5.5	5.7	5.7	5.6	5.6	5.6	5.2	6.1

Figure	GD305A-3	GD510R-1	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Fuel tank per engine horsepower	0.34 gal	0.48 gal	0.44 gal	0.44 gal	0.48 gal	0.48 gal	0.48 gal	0.48 gal	0.42 gal

GD305A-3 and 11 related models: forum references

Dated forum-index scope
Forum index	Exact-model query	Exact-model title matches	Broader equipment query	Broader title matches
Heavy Equipment Forums	Komatsu motor grader	0	Komatsu motor graders	3

Komatsu 5 Motor Graders (Heavy Equipment Forums, 2015-07-14)
Komatsu Gd555 3 Graders (Heavy Equipment Forums, 2013-11-18)
New Komatsu Graders (Heavy Equipment Forums, 2009-10-29)

Used market for the GD305A-3 and 11 related models — Dated first-page listing snapshot
Observation date	Listing source	Equipment search	Listings
2026-09-24	MachineryTrader	Komatsu motor grader	2

Model	Listed	Model years	Lowest asking	Highest asking	Median asking	Median hours
GD305A-3	1	Not stated	$48,956	$48,956	$48,956	None shown
GD623A-1	1	2015	$29,792	$29,792	$29,792	None shown

GD305A-3 and 11 related models: 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 motor grader GD305A-3, GD500R-2, GD510R-1, GD505A-2	No matching recall in this search

Sources for this page
Evidence class	Document, classification and recorded date
Reference site	Reference site: Komatsu GD305A-3 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD500R-2 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD510R-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD505A-2 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD505R-2 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD521A-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD511A-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD611A-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD621R-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD623A-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD625A-1 — RitchieSpecs. Observed 2026-09-24.
Reference site	Reference site: Komatsu GD661A-1 — RitchieSpecs. Observed 2026-09-24.
Forum threads	Forum threads: Heavy Equipment Forums thread index for Komatsu GD305A-3 and 11 related models — Heavy Equipment Forums. Observed 2026-09-24.
Used-market listings	Used-market listings: MachineryTrader listings for Komatsu GD305A-3 — 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.

Komatsu GD305A-3 and 11 related models: Configuration records

GD305A-3

Specification	Source figure
Dimensions and weight
Overall Length	22.76 ft
Wheelbase	16.41 ft
Blade Base	6.94 ft
Height To Top Of Isomount Cab	8.01 ft
Width Over Tires	6.89 ft
Tandem Axle Wheelbase	4.38 ft
Engine
Engine Model	S4D102E
Max Power	100 hp
Displacement	239.3 cu in
Number Of Cylinders	4
Net Power Gear 4-6	100 hp
Power Measured @	2,500 rpm
Operational
Std Operation Weight - Total	17,593 lb
Tire Size	front 9.00-20-8PR rear 10.00-20-10PR
Fuel Capacity	34.4 gal
Steering
Articulation Angle	27 degrees
Turning Radius	18.7 ft
Transmission and speeds
Number Of Gears - Forward	4
Number Of Gears - Reverse	1
Max Speed - Forward	21.5 mph
Max Speed - Reverse	15.3 mph
Moldboard
Moldboard Width	10.4 ft
Moldboard Height	20.9 in

Source

GD500R-2

Specification	Source figure
Dimensions and weight
Overall Length	25.99 ft
Wheelbase	18.97 ft
Rear Ground Clearance	1.24 ft
Front Ground Clearance	1.81 ft
Blade Base	8.34 ft
Height To Top Of Isomount Cab	9.77 ft
Width Over Tires	7.67 ft
Tandem Axle Wheelbase	4.94 ft
Engine
Engine Model	S6D105-1
Max Power	130 hp
Displacement	396 cu in
Net Power Gear 4-6	130 hp
Net Torque Gears 3-4	345 lb-ft
Operational
Std Operation Weight - Front Axle	6,471 lb
Std Operation Weight - Rear Axle	16,678 lb
Std Operation Weight - Total	23,149 lb
Tire Size	13.00-24-8PR (G-2)
Steering
Turning Radius	34.2 ft
Transmission and speeds
Number Of Gears - Forward	4
Number Of Gears - Reverse	4
Max Speed - Forward	25.7 mph
Max Speed - Reverse	15.9 mph
Transmission Type	constant mesh
Front Axle
Oscillation - Total	30 degrees
Ground Clearance	1.9 ft
Wheel Lean	20 degrees
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.8 in
Moldboard Thickness	0.8 in
Max Depth Of Cut	19.9 in
Circle
Max Reach Outside Tires - Left	80.8 in
Max Reach Outside Tires - Right	78.8 in
Max Lift Above Ground	17 in

Source

GD510R-1

Specification	Source figure
Dimensions and weight
Overall Length	25.69 ft
Wheelbase	18.97 ft
Front Ground Clearance	1.2 ft
Blade Base	8.34 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	S6D95L
Max Power	124.8 hp
Displacement	298.5 cu in
Number Of Cylinders	6
Net Power Gear 4-6	124.8 hp
Power Measured @	2,500 rpm
Operational
Std Operation Weight - Total	23,590 lb
Tire Size	13.00-24-8PR
Fuel Capacity	60 gal
Steering
Turning Radius	34.2 ft
Transmission and speeds
Number Of Gears - Forward	4
Number Of Gears - Reverse	4
Max Speed - Forward	26.7 mph
Max Speed - Reverse	16.6 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

GD505A-2

Specification	Source figure
Dimensions and weight
Overall Length	25.99 ft
Wheelbase	18.97 ft
Rear Ground Clearance	1.15 ft
Front Ground Clearance	1.81 ft
Blade Base	8.34 ft
Height To Top Of Isomount Cab	9.11 ft
Width Over Tires	7.67 ft
Tandem Axle Wheelbase	4.94 ft
Engine
Engine Model	S6D105-1
Net Power Gear 5-6	130 hp
Max Power	130 hp
Net Torque Gears 5-6	345 lb-ft
Displacement	396 cu in
Aspiration	turbocharged
Operational
Std Operation Weight - Front Axle	6,526 lb
Std Operation Weight - Rear Axle	17,461 lb
Std Operation Weight - Total	23,986 lb
Tire Size	13.00-24-8PR
Steering
Turning Radius	21.7 ft
Transmission and speeds
Number Of Gears - Forward	6
Number Of Gears - Reverse	6
Max Speed - Forward	27 mph
Max Speed - Reverse	28 mph
Transmission Type	Hydroshift
Front Axle
Oscillation - Total	30 degrees
Ground Clearance	1.9 ft
Wheel Lean	20 degrees
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.8 in
Moldboard Thickness	0.8 in
Max Depth Of Cut	19.9 in
Circle
Max Reach Outside Tires - Left	80.8 in
Max Reach Outside Tires - Right	78.8 in
Max Lift Above Ground	17 in

Source

GD505R-2

Specification	Source figure
Dimensions and weight
Overall Length	26.51 ft
Wheelbase	18.97 ft
Rear Ground Clearance	1.15 ft
Front Ground Clearance	1.81 ft
Blade Base	8.34 ft
Height To Top Of Isomount Cab	9.77 ft
Width Over Tires	7.67 ft
Tandem Axle Wheelbase	4.94 ft
Engine
Engine Model	S6D105
Net Power Gear 5-6	130 hp
Max Power	130 hp
Displacement	396 cu in
Operational
Std Operation Weight - Front Axle	6,614 lb
Std Operation Weight - Rear Axle	17,042 lb
Std Operation Weight - Total	23,656 lb
Tire Size	13.00-24-8 PR
Steering
Articulation Angle	36 degrees
Turning Radius	34.2 ft
Transmission and speeds
Number Of Gears - Forward	6
Number Of Gears - Reverse	6
Max Speed - Forward	27 mph
Max Speed - Reverse	28 mph
Transmission Type	Hydroshift
Front Axle
Oscillation - Total	30 degrees
Ground Clearance	1.9 ft
Wheel Lean	20 degrees
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.8 in
Moldboard Thickness	0.8 in
Max Depth Of Cut	19.9 in
Circle
Max Reach Outside Tires - Left	80.8 in
Max Reach Outside Tires - Right	78.8 in
Max Lift Above Ground	17 in

Source

GD521A-1

Specification	Source figure
Dimensions and weight
Overall Length	26.78 ft
Wheelbase	18.97 ft
Rear Ground Clearance	1.19 ft
Blade Base	8.34 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	S6D105
Net Power Gear 5-6	135.5 hp
Max Power	135.5 hp
Displacement	396.1 cu in
Number Of Cylinders	6
Power Measured @	2,500 rpm
Operational
Std Operation Weight - Total	23,810 lb
Tire Size	13.00-24-8PR
Fuel Capacity	60 gal
Steering
Articulation Angle	27 degrees
Turning Radius	21.7 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	27.8 mph
Max Speed - Reverse	33.9 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

GD511A-1

Specification	Source figure
Dimensions and weight
Overall Length	25.91 ft
Wheelbase	18.97 ft
Rear Ground Clearance	1.2 ft
Blade Base	8.34 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	S6D95L
Net Power Gear 5-6	135.5 hp
Max Power	135.5 hp
Displacement	298.5 cu in
Number Of Cylinders	6
Power Measured @	2,900 rpm
Operational
Std Operation Weight - Total	23,810 lb
Tire Size	13.00-24-8PR
Fuel Capacity	60 gal
Steering
Articulation Angle	27 degrees
Turning Radius	21.7 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	27.7 mph
Max Speed - Reverse	33.9 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

GD611A-1

Specification	Source figure
Dimensions and weight
Overall Length	27.5 ft
Wheelbase	19.69 ft
Rear Ground Clearance	1.17 ft
Blade Base	8.54 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	S6D105
Net Power Gear 5-6	155.6 hp
Max Power	155.6 hp
Displacement	396.1 cu in
Number Of Cylinders	6
Power Measured @	2,500 rpm
Operational
Std Operation Weight - Total	27,558 lb
Tire Size	13.00-24-10PR
Fuel Capacity	75.3 gal
Steering
Articulation Angle	26 degrees
Turning Radius	22.7 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	27.8 mph
Max Speed - Reverse	33.9 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

GD621R-1

Specification	Source figure
Dimensions and weight
Overall Length	27.5 ft
Wheelbase	19.69 ft
Rear Ground Clearance	1.17 ft
Blade Base	8.54 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	S6D105
Net Power Gear 5-6	155.6 hp
Max Power	155.6 hp
Displacement	396.1 cu in
Number Of Cylinders	6
Power Measured @	2,500 rpm
Operational
Std Operation Weight - Total	27,999 lb
Tire Size	13.00-24-10PR
Fuel Capacity	75.3 gal
Steering
Turning Radius	34.2 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	27.8 mph
Max Speed - Reverse	33.9 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

GD623A-1

Specification	Source figure
Dimensions and weight
Overall Length	27.89 ft
Wheelbase	19.69 ft
Rear Ground Clearance	1.17 ft
Blade Base	8.54 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	6D125
Net Power Gear 5-6	155.6 hp
Max Power	155.6 hp
Displacement	674.4 cu in
Number Of Cylinders	6
Power Measured @	2,200 rpm
Operational
Std Operation Weight - Total	27,999 lb
Tire Size	13.00-24-10PR
Fuel Capacity	75.3 gal
Steering
Articulation Angle	26 degrees
Turning Radius	22.7 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	28.9 mph
Max Speed - Reverse	35.3 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

GD625A-1

Specification	Source figure
Dimensions and weight
Overall Length	27.89 ft
Wheelbase	19.69 ft
Rear Ground Clearance	1.17 ft
Blade Base	8.54 ft
Height To Top Of Isomount Cab	10.85 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	6D125
Net Power Gear 5-6	155.6 hp
Max Power	155.6 hp
Displacement	674.4 cu in
Number Of Cylinders	6
Power Measured @	2,200 rpm
Operational
Std Operation Weight - Total	30,203 lb
Tire Size	13.00-24-10PR
Fuel Capacity	75.3 gal
Steering
Articulation Angle	26 degrees
Turning Radius	22 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	28 mph
Max Speed - Reverse	34.1 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.1 ft
Moldboard Height	25.4 in

Source

GD661A-1

Specification	Source figure
Dimensions and weight
Overall Length	27.5 ft
Wheelbase	19.69 ft
Rear Ground Clearance	1.17 ft
Blade Base	8.54 ft
Height To Top Of Isomount Cab	11.44 ft
Width Over Tires	7.86 ft
Tandem Axle Wheelbase	5.04 ft
Engine
Engine Model	S6D105
Net Power Gear 5-6	179.7 hp
Max Power	179.7 hp
Displacement	396.1 cu in
Number Of Cylinders	6
Power Measured @	2,500 rpm
Operational
Std Operation Weight - Total	29,322 lb
Tire Size	13.00-24-10PR
Fuel Capacity	75.3 gal
Steering
Articulation Angle	26 degrees
Turning Radius	22.7 ft
Transmission and speeds
Number Of Gears - Forward	6
Max Speed - Forward	27.8 mph
Max Speed - Reverse	33.9 mph
Front Axle
Ground Clearance	1.2 ft
Moldboard
Moldboard Width	12.2 ft
Moldboard Height	25.4 in

Source

Compare Komatsu GD305A-3, GD500R-2, GD510R-1, GD505A-2, GD505R-2, GD521A-1, GD511A-1, GD611A-1, GD621R-1, GD623A-1, GD625A-1, GD661A-1

Dimensions and weight
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Overall Length	22.76 ft	25.99 ft	25.69 ft	25.99 ft	26.51 ft	26.78 ft	25.91 ft	27.5 ft	27.5 ft	27.89 ft	27.89 ft	27.5 ft
Width Over Tires	6.89 ft	7.67 ft	7.86 ft	7.67 ft	7.67 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft	7.86 ft
Wheelbase	16.41 ft	18.97 ft	18.97 ft	18.97 ft	18.97 ft	18.97 ft	18.97 ft	19.69 ft	19.69 ft	19.69 ft	19.69 ft	19.69 ft
Tandem Axle Wheelbase	4.38 ft	4.94 ft	5.04 ft	4.94 ft	4.94 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft	5.04 ft
Blade Base	6.94 ft	8.34 ft	8.34 ft	8.34 ft	8.34 ft	8.34 ft	8.34 ft	8.54 ft	8.54 ft	8.54 ft	8.54 ft	8.54 ft
Height To Top Of Isomount Cab	8.01 ft	9.77 ft	11.44 ft	9.11 ft	9.77 ft	11.44 ft	11.44 ft	11.44 ft	11.44 ft	11.44 ft	10.85 ft	11.44 ft

Engine
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Engine Model	S4D102E	S6D105-1	S6D95L	S6D105-1	S6D105	S6D105	S6D95L	S6D105	S6D105	6D125	6D125	S6D105
Max Power	100 hp	130 hp	124.8 hp	130 hp	130 hp	135.5 hp	135.5 hp	155.6 hp	155.6 hp	155.6 hp	155.6 hp	179.7 hp
Displacement	239.3 cu in	396 cu in	298.5 cu in	396 cu in	396 cu in	396.1 cu in	298.5 cu in	396.1 cu in	396.1 cu in	674.4 cu in	674.4 cu in	396.1 cu in

Operational
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Std Operation Weight - Total	17,593 lb	23,149 lb	23,590 lb	23,986 lb	23,656 lb	23,810 lb	23,810 lb	27,558 lb	27,999 lb	27,999 lb	30,203 lb	29,322 lb
Tire Size	front 9.00-20-8PR rear 10.00-20-10PR	13.00-24-8PR (G-2)	13.00-24-8PR	13.00-24-8PR	13.00-24-8 PR	13.00-24-8PR	13.00-24-8PR	13.00-24-10PR	13.00-24-10PR	13.00-24-10PR	13.00-24-10PR	13.00-24-10PR

Steering
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Turning Radius	18.7 ft	34.2 ft	34.2 ft	21.7 ft	34.2 ft	21.7 ft	21.7 ft	22.7 ft	34.2 ft	22.7 ft	22 ft	22.7 ft

Transmission and speeds
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Number Of Gears - Forward	4	4	4	6	6	6	6	6	6	6	6	6
Max Speed - Forward	21.5 mph	25.7 mph	26.7 mph	27 mph	27 mph	27.8 mph	27.7 mph	27.8 mph	27.8 mph	28.9 mph	28 mph	27.8 mph
Max Speed - Reverse	15.3 mph	15.9 mph	16.6 mph	28 mph	28 mph	33.9 mph	33.9 mph	33.9 mph	33.9 mph	35.3 mph	34.1 mph	33.9 mph

Moldboard
Specification	GD305A-3	GD500R-2	GD510R-1	GD505A-2	GD505R-2	GD521A-1	GD511A-1	GD611A-1	GD621R-1	GD623A-1	GD625A-1	GD661A-1
Moldboard Width	10.4 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.2 ft	12.1 ft	12.2 ft
Moldboard Height	20.9 in	25.8 in	25.4 in	25.8 in	25.8 in	25.4 in	25.4 in	25.4 in	25.4 in	25.4 in	25.4 in	25.4 in

More in Komatsu: GD31RC-3A/GD405A-1, GD200A-1/GD300A-1, GD530A-2C–GD670AW-2C.

Komatsu GD305A-3 and 11 related models specifications

GD305A-3 and 11 related models: forum references

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Komatsu GD305A-3 and 11 related models: Configuration records