Wheel Tractor-Scraper K Series Wheel Tractor-Scraper K Series
Wheel Tractor-Scraper K Series Operator Testimonial Wheel Tractor-Scraper K Series Operator Testimonial
Wheel Tractor Scraper CAT® 631K C202 Wheel Tractor Scraper CAT® 631K C202
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Flywheel Power - Tractor/Scraper570 HP (425 kW)
Scraper Capacity - Heaped34 yd³ (26 m³)
Top Speed - Loaded34.7 mile/h (55.8 km/h)
Front of Tractor to Front Axle142.2 in (3612 mm)
Cat’s 637K Wheel Tractor-Scraper is engineered to conquer challenges operators face worldwide. With its strength and durability, it works in some of the most difficult conditions and materials one can find.


Flywheel Power - Tractor/Scraper570 HP (425 kW)
Scraper Capacity - Heaped34 yd³ (26 m³)
Top Speed - Loaded34.7 mile/h (55.8 km/h)
Front of Tractor to Front Axle142.2 in (3612 mm)
Axle to Vertical Hitch Pin20 in (509 mm)
Wheel Base346.8 in (8808 mm)
Rear Axle - Rear of Machine90.2 in (2292 mm)
Width - Overall Machine155 in (3937 mm)
Exterior Sound LevelThe exterior sound power level for the standard machine (ISO 6393) is 116 dB(A).
BrakesISO 3450:2011
Rollover Protection Structure (ROPS)ISO 3471:2008 for up to 21 282 kg (46,919 lb)
Reverse AlarmISO 9533:2010
Seat BeltSAE J386:FEB2006
Operating Weight - Empty114950 lb (52140 kg)
ROPS/FOPSROPS/FOPS meet “ISO Standards.”
Operating Weight - Empty119060 lb (54005 kg)
Overall Length - With Bail Down54.59 ft (16.64 m)
Width - Tractor137.8 in (3499 mm)
Ground Clearance - Tractor26.1 in (664 mm)
Height - Top of Cab147 in (3733 mm)
Overall Length49.34 ft (15.04 m)
Rated Load37 200 kg (82,200 lb); 37.2 tonnes (41.1 tons)
Extended Push Block (Push-Pull)108 in (2744 mm)
Transmission Gear - Sixth19 mile/h (30.6 km/h)
Bail Raise1.5 s (1.5 s)
Apron Raise4 s (4 s)
Bowl Lower3.5 s (3.5 s)
Bowl Raise3.5 s (3.5 s)
Apron Lower3.8 s (3.8 s)
Ejector Extend8.5 s (8.5 s)
Bail Lower2.1 s (2.1 s)
Transmission Gear - Second6.2 mile/h (10 km/h)
Falling Object Protective Structure (FOPS)ISO 3449:2005 Level II
Transmission Gear - Fourth10.5 mile/h (16.9 km/h)
Transmission Gear - Eighth34.7 mile/h (55.8 km/h)
Transmission Gear - Fifth14.1 mile/h (22.7 km/h)
Transmission Gear - Seventh25.7 mile/h (41.95 km/h)
Transmission Gear - First3.4 mile/h (5.5 km/h)
Transmission Gear - Reverse6.2 mile/h (9.9 km/h)
Transmission Gear - Third7.7 mile/h (12.4 km/h)
Steering SystemISO 5010:2007
Width - Rear Tire Centers96.9 in (2462 mm)
Length - Overall Machine - Standard597 in (15164 mm)
Length - Maximum (Push-Pull)655.1 in (16640 mm)
Tires - Scraper37.25R35**E3
Flywheel Power - Scraper290 HP (216 kW)
Rated Engine RPM - Scraper2150 r/min (2150 r/min)
Rated Engine RPM - Tractor1900 r/min (1900 r/min)
Tires - Tractor37.25R35**E3
Scraper Capacity - Struck24 yd³ (18.3 m³)
Maximum Depth of Spread21.1 in (535 mm)
Maximum Depth of Cut17.7 in (450 mm)
EmissionsCat C9.3 and C18 engines meet U.S. EPA Tier 4 Final/EU Stage IV emission standards.
Width - Cut11.5 ft (3.51 m)
Scraper Capacity - Heaped34 yd³ (26 m³)
Top Speed - Loaded34.7 mile/h (55.8 km/h)
Overall Width12.93 ft (3.94 m)
Overall Shipping Height13.62 ft (4.15 m)
180° Curb-to-Curb Turning Width40.12 ft (12.23 m)
Engine Model - ScraperCat C9.3
Flywheel Power - Tractor570 HP (425 kW)
Width - Outside Rear Tires143.2 in (3636 mm)
Transmission System - Scraper12.9 gal (US) (49 l)
Height - Overall Shipping163.2 in (4145 mm)
Fuel Tank Refill Capacity - Scraper370 gal (US) (1400 l)
Height - Scraper Blade Maximum20 in (510 mm)
Width - Inside of Bowl134 in (3404 mm)
Cooling System - Tractor19.8 gal (US) (75 l)
Cooling System - Scraper16.1 gal (US) (61 l)
Fuel Tank370 gal (US) (1400 l)
Engine Model - TractorCat C18
Diesel Exhaust Fluid - Tractor8 gal (US) (30.5 l)
Diesel Exhaust Fluid - Scraper5.8 gal (US) (22 l)
Hydraulic System37.5 gal (US) (142 l)
Transmission System - Tractor29 gal (US) (110 l)
Crankcase - Scraper6.5 gal (US) (24.5 l)
Crankcase - Tractor13.7 gal (US) (52 l)
Ejector Retract8.5 s (8.5 s)

Benefits and Features

  • 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.
  • 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.
  • Fuel Economy Mode is a two part feature when selected. The first part of the feature lowers the transmission shift points allowing shifting to take place at lower rpms to aid in fuel savings. The second part of the Fuel Economy Mode allows the machine when operated at engine rpms less than full throttle to automatically vary the power distribution between the tractor and the scraper.
  • The Payload Estimator (optional) 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.
  • 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.
  • 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.
  • 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.

  • 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.
  • The K Series cab interior improves operator comfort and visibility. The overall interior is 21% larger than the G Series cab.
  • 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.

  • Tire Spin Reduction feature will allow the machine to control the slip of the tractor tires only.
  • 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 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.

Standard Equipment

  • Cat C18 engine with MEUI™
  • 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
  • Starting aid, ether
  • Braking system:
    • Primary and secondary, wet disc, hydraulic actuated
    • 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
  • Cat C9.3 engine:
    • High pressure common rail fuel
    • Constant lift engine brake
  • Electric start, 24V
  • Air cleaner, dry type with precleaner
  • Fan, mechanical driven
  • Ground level engine shutdown
  • Radiator, aluminum unit core, 9 fins per inch
  • Starting aid, either
  • Braking system:
    • Primary and secondary, dry caliper, hydraulic actuated
  • Transmission:
    • 4-speed (torque converter drive)
    • Planetary power shift
  • 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
  • Batteries (4) 12V, 1,000 CCA, maintenance free, high output
  • Alternator, 65 Amp
  • Electrical system, 24V
  • 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
    • Diesel Particulate Filter (DPF) temperature
    • Fuel level
    • Park brake
    • Implement lockout
    • Brake system
    • Regeneration required
    • 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
    • DEF fill levels
  • 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
  • Scraper fenders
  • Overflow guard
  • Fast oil change
  • Rims (2)
  • Hydraulic position sensing cylinders (bowl lift and apron)

Optional Equipment

  • 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
  • Wiring group
  • Push Pull
  • Film arrangement – U.S. (ANSI)
  • Film arrangement – International (ISO)