621 Partial Scraper

621 Partial Scraper

Caterpillar offers partial wheel tractor-scraper power units designed for specialty machines that complement the traditional Cat® product line. These tractor-only configurations are available for purchase directly from Caterpillar OEM Solutions. They can be leveraged for a variety of final machines, including water pulls, elevating scrapers, lowboy trailer power units, and more. With improvements in productivity combined with enhancements in operator comfort and new safety features – Powered Access System and effective wet disc brakes – this machine offers high returns on time and investment.

Tractor Engine Cat® C13 Cat® C13
Flywheel Power - Tractor 407 HP 304 kW
Top Speed - Loaded 33.5 mile/h 53.9 km/h

Technicial Specifications

Tractor Engine Cat® C13 Cat® C13
Flywheel Power - Tractor 407 HP 304 kW
Note Meets U.S. EPA Tier 4 Final or EU Stage V emission standards, or equivalent to U.S. EPA Tier 2, or equivalent to U.S. EPA Tier 3 and EU Stage IIIA. Meets U.S. EPA Tier 4 Final or EU Stage V emission standards, or equivalent to U.S. EPA Tier 2, or equivalent to U.S. EPA Tier 3 and EU Stage IIIA.
Top Speed - Loaded 33.5 mile/h 53.9 km/h
1 Forward 3.1 mile/h 5 km/h
2 Forward 5.5 mile/h 8.9 km/h
3 Forward 7.5 mile/h 12.1 km/h
4 Forward 10.1 mile/h 16.3 km/h
5 Forward 13.6 mile/h 21.9 km/h
6 Forward 18.4 mile/h 29.6 km/h
7 Forward 24.8 mile/h 39.9 km/h
8 Forward 33.5 mile/h 53.9 km/h
Reverse 5.7 mile/h 9.2 km/h
Brakes ISO 3450:2011 ISO 3450:2011
ROPS/FOPS ROPS: ISO 3471:2008 for up to 17 084 kg (37,664 lb). FOPS: ISO 3449:2005 Level II. ROPS: ISO 3471:2008 for up to 17 084 kg (37,664 lb). FOPS: ISO 3449:2005 Level II.
Cab Seat Belt: SAE J386:JUN1985 Seat Belt: SAE J386:JUN1985
Width - 180° Turn 38.6 ft 11.8 m
Service Refill Capacities - Tractor
Fuel Tank 216.1 gal (US) 818 l
Crankcase 9.7 gal (US) 37 l
Transmission 25.5 gal (US) 97 l
Differential 41.7 gal (US) 158 l
Final Drive - Each 5 gal (US) 19 l
Cooling System 11 gal (US) 42 l
Hydraulic Reservoir 21.9 gal (US) 83 l
Windshield Washer 1.3 gal (US) 5 l

Advantages and Features


  • Steer with less effort with the newly designed high-pressure steering system.
  • Enjoy interior improvements and a more ergonomic work environment.
  • Intuitive, ergonomic controls with multifunction display keep operators focused on their work.
  • Maintain desired cab temperature with automatic temperature control.


  • Cat Advanced Ride Management (ARM) seat suspension reduces end stroke movement of the load cylinder for a smoother ride.
  • Engine overspeed protection will automatically engage with no operator input when the machine is in eighth gear. The machine will assist in slowing the machine speed by canceling the throttle command and engaging the engine compression brake.


  • The Advanced Productivity Electronic Control System (APECS) allows the machine to better utilize engine power and torque.
  • Set the desired top speed with Ground Speed Control, and the machine will find the gear that works best for the engine and the transmission, providing a lower fuel burn in speed reduced areas.
  • The Machine Speed Limit feature replaces Top Gear Selection.
  • Auto-Stall assists in quickly bringing the transmission to an operating temperature at start-up when working in colder climates.


  • Get in and out of the cab easier with the new powered access ladder system.
  • Enhance the operator’s awareness of site surroundings with the optional Work Area Vision System (WAVS).
  • Ground-level access to fuel fill and several maintenance points for easier and safer service.
  • Seat belt indicator provides visual and audible alerts when the seat belt is not in use.
  • Wide brake shoes and brake drums improve brake performance and reduce brake and drum wear.
  • Secondary brakes engage automatically if service pressure drops
  • Parking Brake features a spring-applied, hydraulic pressure released mechanism that operates the service brakes.



  • Full support of Cat dealer and parts network.
  • Eligible for Equipment Protection Plans (EPP) & Customer Value Agreements (CVAs).

Standard Equipment

  • NOTE
    • Standard and optional equipment may vary. Consult your Cat dealer for details.
    • Cat® C13 engine with Mechanically Actuated Electronic Unit Injection (MEUI™)
    • Transmission: 8-speed planetary powershift, ECPC control, APECS software, programmable top gear selection, transmission hold, differential lock, guard - power train, ground speed control, machine speed limit
    • Cat engine brake
    • Electric start, 24V
    • Fan, hydraulic
    • Ground level engine shutdown
    • Guard, crankcase
    • Starting aid, ether
    • Braking system: primary and secondary, wet disc, hydraulic; parking, hydraulic-released, spring-applied
    • Alternator, 115 ampere
    • Batteries (4), 12V, 1,000 CCA, maintenance free, high output
    • Electrical system, 24V
    • Lighting system: LED
    • Starting/charging receptacle
    • HVAC system, heat, AC, defrost
    • Thermostat control of HVAC system
    • Coat hook
    • Lunchbox platform with holding strap
    • Diagnostic connection (2)
    • 12V power ports (2)
    • Differential lock
    • Dome courtesy light
    • Horn, electric
    • T-handle implement control
    • Radio ready
    • ROPS/FOPS cab, pressurized
    • Keypad switches: rear engine start; throttle lock; wipers/washers; hazard lights; worklights on, off; information mode; messenger display; safety tab rocker switches, parking brake
    • Seat belt, static two-piece
    • Windows, sliding
    • Windshield wipers, front and rear windows, includes washers
    • Windows, laminated, zipped in
    • Mirror, rearview
    • Door lock
    • Messenger display gauges, warnings include: coolant temp; engine oil temp; hydraulic oil temp; DPF temp; fuel level; park brake; implement lockout; brake system, regeneration required; throttle lock; system voltage; secondary steering; bail down; differential lock; apron float; transmission hold; high beam lights; action lamp; engine speed, rpm; gear selection; DPF fill levels
    • Safety tab rocker switches
    • Seat: Cat Advanced Ride Management (ARM), Cat Comfort Series III, rotates 30 degrees
    • Steering wheel, tilt, telescoping, padded
    • Windows, right side emergency egress
    • Messenger display
    • Extended life coolant to -37° C (-34° F)
    • Advanced cushion hitch
    • Accumulators (cushion hitch and brake) with Canadian registration number (CRN)
    • Tow pin, front
    • Fenders, non-metallic
    • Heater, engine coolant 120V
    • Fast-fill fuel tank

Optional Equipment

    • Camera arrangement: Work Area Vision System (WAVS)
    • Cab beacon
    • Air horn
    • Air horn and beacon
    • Kingbolt housing
    • Rear wheel arrangement (set of 2)
    • Scraper draft arm package
    • Steering cylinder group (set of 2)