360°Exterior View
360°Interior View

631K Wheel Tractor-Scraper

  • Overview
  • Finance With CavPower
  • Optional Services
  • View product Download


  • The Payload Estimator will calculate the payload of the machine in tonnes or tons by measuring the bowl lift cylinder pressures at the beginning of the loaded haul segment. This feature works best when using Sequence Assist. Using Payload Estimator during testing has achieved better than 95% accuracy when compared to actual scale weights. The Payload Estimator feature comes automatically when a machine is ordered with Sequence Assist.
  • Load Assist (Optional) is designed to help shorten the learning curve of inexperienced operators to ensure consistency and faster loading of material while reducing effort of the operator. Based on the speed of the machine, Load Assist automatically adjusts the cutting edge height to manage wheel slip and to ensure consistent and efficient loading in bulk earthmoving applications.
  • Machine Speed Limit is designed to take the place of top gear selection. If the machine top speed needs to be limited the operator can select the top speed through the display or the top speed can be set in ET. This will allow the machine to find the correct gear that works best for the engine and transmission. Allowing the engine and transmission to select the correct gear to pull the load in most cases resulting in a lower engine load factor and lower fuel burn verses using top gear selection that required the machine to run at engine speeds at or close to high idle.
  • Sequence Assist (Optional) uses cylinder position sensors to automate bowl, apron and further implement controls throughout the four core work cycles: Dig, Haul, Unload and Return. When utilized this can reduce up to 14 individual operator commands per cycle. Sequence Assist simplifies control over the implements, reduces joystick usage, automatically controls cushion hitch, transmission hold and ejector.
  • Ground Speed Control sets the desired top speed by the operator if job site conditions or segment speed limits require a speed less than full run out. Machine Speed Limit is intended for use when top speed needs to be limited for longer durations and Ground Speed Control is intended for use when the top speed needs to be reduced for shorter segments or intermediate periods of time. The operator can set the desired top speed and the machine will find the correct gear that works best for the engine and transmission.
  • Cat Grade Control (Optional) intelligently ensures the machine does not cut below grade in the cut area or over fill in the fill area – avoiding rework and moving unnecessary material.


  • K Series steering system design requires significantly less steering effort. The reduced steering effort will allow for decreased operator fatigue and a more efficient operator resulting in possible higher rates of production late in the work cycle.
  • Advanced Cushion Hitch allows the cushion hitch to prevent end stroke by having the ability to predict end stroke events and manage the rate of dampening. Resulting in reduced hitch maintenance and improved operator ride in rough conditions.
  • The K Series cab interior improves operator comfort and visibility. The overall interior is 21% larger than the G Series cab.


  • In the event of an engine over speed situation, the compression brake or brakes will automatically engage with no operator input. The machine determines the over speed condition based on rate of acceleration and applies compression brakes automatically.
  • Differential Lock Engagement Protection
     - This standard feature allows the machine to prevent the operator from engaging the differential lock when damage could occur.


  • The fuel, water and engine oil are relocated at ground level on the right hand side of the machine for easy access.

Overall Shipping Height 3.89 m (12.75 ft)
Maximum Depth of Spread 535 mm (21.1 in)
Tires - Tractor 37.25R35**E3
Fuel Tank Refill Capacity - Scraper 874 l (231 gal (US))
Scraper Capacity - Struck 18.3 mu00b3 (24 ydu00b3)
Scraper Capacity - Heaped 26 mu00b3 (34 ydu00b3)
Top Speed - Loaded 55.8 km/h (34.7 mile/h)
Overall Width 3.94 m (12.93 ft)
Maximum Depth of Cut 450 mm (17.7 in)
Width - Cut 3.51 m (11.5 ft)
180u00b0 Curb-to-Curb Turning Width 12.23 m (40.12 ft)
Rated Load 37 200 kg (82,200 lb); 37.2 tonnes (41.1 tons)
Tires - Scraper 37.25R35**E3
Rated Engine RPM - Tractor 1900 r/min (1900 r/min)
Engine Model - Tractor Cat C18
Emissions Cat C18 engine meets U.S. EPA Tier 2/EU Stage II Equivalent emission standards.
Flywheel Power - Tractor 425 kW (570 HP)
Tractor Engine
Flywheel Power - Tractor/Scraper 425 kW (570 HP)
Scraper Bowl
Scraper Capacity - Heaped 26 mu00b3 (34 ydu00b3)
Top Speed - Loaded 55.8 km/h (34.7 mile/h)
Service Refill Capacities
Crankcase - Tractor 52 l (13.7 gal (US))
Transmission System 110 l (29 gal (US))
Fuel Tank 874 l (231 gal (US))
Hydraulic System 142 l (37.5 gal (US))
Cooling System 75 l (19.8 gal (US))
Front of Tractor to Front Axle 3612 mm (142.2 in)
Axle to Vertical Hitch Pin 509 mm (20 in)
Wheel Base 8808 mm (346.8 in)
Rear Axle - Rear of Machine 2744 mm (108 in)
Ground Clearance - Tractor 664 mm (26.1 in)
Width - Outside Rear Tires 3636 mm (143.2 in)
Width - Inside of Bowl 3404 mm (134 in)
Width - Rear Tire Centers 2462 mm (96.9 in)
Height - Scraper Blade Maximum 510 mm (20 in)
Height - Top of Cab 3733 mm (147 in)
Length - Maximum (Push-Pull) 16640 mm (655.1 in)
Height - Overall Shipping 3892 mm (153.2 in)
Width - Overall Machine 3937 mm (155 in)
Length - Overall Machine - Standard 15164 mm (597 in)
Width - Tractor 3499 mm (137.8 in)
Non Push-Pull
Operating Weight - Empty 46600 kg (102750 lb)
Overall Length 15.04 m (49.34 ft)
Overall Length - With Bail Down 16.64 m (54.59 ft)
Operating Weight - Empty 48275 kg (106430 lb)
Exterior Sound Level The exterior sound power level for the standard machine (ISO 6393) is 111.5 dB(A).
ROPS/FOPS ROPS/FOPS meet u201cISO Standards.u201d
Safety Criteria Compliance Standards
Reverse Alarm ISO 9533:2010
Falling Object Protective Structure (FOPS) ISO 3449:2005 Level II
Seat Belt SAE J386:FEB2006
Rollover Protection Structure (ROPS) ISO 3471:2008 for up to 21 282 kg (46,919 lb)
Brakes Brakes ISO 3450:2011
Steering System ISO 5010:2007
Travel Speeds - Runout
Transmission Gear - First 5.5 km/h (3.4 mile/h)
Transmission Gear - Fourth 16.9 km/h (10.5 mile/h)
Transmission Gear - Sixth 30.6 km/h (19 mile/h)
Transmission Gear - Third 12.4 km/h (7.7 mile/h)
Transmission Gear - Fifth 22.7 km/h (14.1 mile/h)
Transmission Gear - Seventh 41.4 km/h (25.7 mile/h)
Transmission Gear - Reverse 9.9 km/h (6.2 mile/h)
Transmission Gear - Eighth 55.8 km/h (34.7 mile/h)
Transmission Gear - Second 10 km/h (6.2 mile/h)
Implement Cycle Times
Bowl Raise 3.5 s (3.5 s)
Bail Lower 2.1 s (2.1 s)
Apron Raise 4 s (4 s)
Ejector Extend 8.5 s (8.5 s)
Bowl Lower 3.5 s (3.5 s)
Bail Raise 1.5 s (1.5 s)
Ejector Retract 8.5 s (8.5 s)
Apron Lower 3.8 s (3.8 s)

Standard Equipment

  • NOTE
    • Standard and optional equipment may vary. Consult your Cat dealer for details.
    • Cat C18
    • Compression engine brake
    • Electric start, 24V
    • Air cleaner, dry type with precleaner
    • Fan, hydraulic
    • Ground level engine shutdown
    • Radiator, aluminum unit core, 9 fins per inch
    • Guard, crankcase
    • Muffler
    • Starting aid, ether
    • Braking system:
      • Primary and secondary, wet disc, hydraulic
      • Parking, hydraulic-released, spring-applied
      • Throttle lock
    • Transmission:
      • 8-speed planetary power shift
      • ECPC control
      • APECS software
      • Programmable top gear selection
      • Transmission hold
      • Differential lock
      • Guard, power train
      • Standard tire spin reduction
      • Ground speed control
      • Machine speed limit
      • Differential lock protection
    • Braking system:
      • Primary and secondary, wet disc, hydraulic
    • Alternator, 150 Amp
    • Batteries (4), 12V, 1,000 CCA, maintenance free, high output
    • Electrical system, 24V
    • Lighting system:
      • Headlights, LED
      • Turn signals with hazard function, LED floodlights, (2) cutting edge (1) bowl, halogen side vision (2)
    • Starting/charging receptacle
    • Alarm, backup
    • Lighting system:
      • Brake lights, LED
      • Turn signals with hazard function, LED
    • 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 (1)
    • Dome courtesy light
    • Horn, electric
    • T-Handle implement control
    • Mirror, rearview
    • Radio ready
    • ROPS/FOPS cab, pressurized
    • Keypad switches:
      • Throttle lock
      • Wipers/washers
      • Hazard lights
      • Retarding level select
      • Work lights on, off
      • Information mode on Messenger Display
    • Safety tab rocker switches
    • Seat belt, static two-piece
    • Seat, Cat Advanced Ride Management (ARM), Cat Comfort Series 3, rotates 30 degrees
    • Steering wheel, tilt, telescoping, padded
    • Windows, right side emergency egress
    • Windows, sliding
    • Windows, laminated, zipped in
    • Windshield wipers, front and rear windows, includes washers
    • Door lock
    • Messenger Display
    • Gauges, warnings include:
      • Coolant temperature
      • Engine oil temperature
      • Hydraulic oil temperature
      • Fuel level
      • Park brake
      • Implement lockout
      • Brake system
      • Throttle lock
      • System voltage
      • Secondary steering
      • Bail down
      • Ejector auto
      • Differential lock
      • Apron float
      • Transmission hold
      • Cushion hitch
      • High beam lights
      • Action lamp
      • Engine speed, rpm
      • Gear selection
    • Extended Life Coolant to –37° C (–34° F)
    • Advanced cushion hitch
    • Accumulators (cushion hitch) with Canadian Registration Number (CRN)
    • Fast oil change
    • Fenders, non-metallic
    • Heater, engine coolant 120V
    • Rims (2)
    • Tow hooks, front
    • Vandalism locks
    • Heater, engine coolant 120V
    • Steering locks
    • Bowl:
      • 18.3 m3 (24 yd3), struck
      • 26 m3 (34 yd3), heaped
    • Vandalism locks
    • Rims (2)
    • Hydraulic position sensing cylinders (bowl lift and apron)

Optional Equipment

  • NOTE
    • Standard and optional equipment may vary. Consult your Cat dealer for details.
    • Secondary Steering Arrangement
    • Sequence Assist Arrangement with Payload Estimator
    • Load Assist
    • Cat Grade Control with Load Assist
    • Advanced Tire Spin Reduction
    • Camera arrangement – Work Area Vision System (WAVS)
    • Cab beacon
    • Air horn
    • Air horn and beacon
    • Fender, scraper
    • Guard, overflow
    • Wiring group
    • Push Pull
    • Year of manufacture plate
    • Film arrangement – International (ISO)

Enquiry Form

    This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.