CT681

Overview
Engine Model
Cat® CT13 Engine
Bore
5 in
Configuration
Inline 6-Cylinder

A natural extension of the Cat® product line, the Cat CT681 Vocational Truck delivers all the power, performance and productivity you expect from Caterpillar. This Class 8 set-forward axle model—ideal for hauling heavy loads—features a spacious and ergonomic cab, industrial styling, vocational-specific engine and transmission options, and bumper-to-bumper support across North America.

Engine

Engine Model
Cat® CT13 Engine
Bore
5 in
Configuration
Inline 6-Cylinder
Stroke
7 in
Displacement
758 in3
Aspiration
Dual Series Turbochargers, Intercooler and Aftercooler
Horse Power at 1700 rpm
365 - 430 hp (268 - 316 kW)
Engine Type
Diesel, 4-Cycle
Compression Ratio
17:1
Combustion System
Direct Injection
Lubrication System Capacity
42 qt (US)
Coolant Drain Interval
600,000 miles (965,606 km)
Total Engine Weight - Dry
2,400 lb
Width
37 in
Length
59 in
Height
49 in
Valves
4 Valves Per Cylinder, Overhead Cam Actuated
Peak Torque - 1000 rpm
1550 lb-ft (2102 N-m)
Engine Model
Cat® CT13 Engine
Bore
5 in
Configuration
Inline 6-Cylinder
Stroke
7 in
Displacement
758 in³
Aspiration
Dual Series Turbochargers, Intercooler and Aftercooler

Transmission

Maximum Gross Input Power
550 mm H2O
Maximum Gross Input Torque
1,700 lb/ft
Transmission Model
Cat CX31® Automatic Transmission
Speeds
6 forward/1 reverse
Torque Converter
Cast aluminum design with lock up clutch
Clutches
Electro-hydraulic fully modulated, oil cooled, multidisc
Maximum Input Speed
2500 rpm
Length
35 in
Overall Length - With Retarder Option
39 in
Overall Weight - Approximate
906 lb
Overall Weight - With Retarder Option
1,088 lb
Power Take-Off
Two side locations and a Cat exclusive high output rear PTO
Rear - PTO Capacity (Rotation Opposite of Engine, at 1.25 Engine Speed)
800 ft-lb
Side - PTO Capacity (Rotation Same as Engine, Ratio Determined by PTO Adaptor)
700 ft-lb

Heavy-Hauling Capacity

The CT681's set-forward axle, rugged design and industrial styling make it ideal for hauling heavy loads or working in extreme conditions. Aluminum alloy cab construction reduces overall weight for maximum payloads.

The CT681's set-forward axle, rugged design and industrial styling make it ideal for hauling heavy loads or working in extreme conditions. Aluminum alloy cab construction reduces overall weight for maximum payloads.

Attachment-Ready Design

Our integral Front Frame Extension (FFE) option makes it easy to mount attachments like snow plows, hose reels, winches and hydraulic pumps. Mixer installation is simple thanks to vertical tie-in plates mounted behind the cab.

Our integral Front Frame Extension (FFE) option makes it easy to mount attachments like snow plows, hose reels, winches and hydraulic pumps. Mixer installation is simple thanks to vertical tie-in plates mounted behind the cab.

Shift-Long Productivity

Comfortable drivers are safe, productive drivers. The CT681's wide, spacious cab is filled with ergonomic details to reduce fatigue and thoughtful features to enhance driver comfort, all shift long.

Comfortable drivers are safe, productive drivers. The CT681's wide, spacious cab is filled with ergonomic details to reduce fatigue and thoughtful features to enhance driver comfort, all shift long.

Safer Driving

Our ergonomically designed dashboard and center stack layout give drivers complete command and control. All controls, levers, switches and gauges are positioned to maximize safety and minimize fatigue, so drivers can stay focused on the job at hand.

Our ergonomically designed dashboard and center stack layout give drivers complete command and control. All controls, levers, switches and gauges are positioned to maximize safety and minimize fatigue, so drivers can stay focused on the job at hand.

Smooth, Quiet Ride

Our tuned cab air suspension system, premium grade sound insulation kit, and durable routing and clipping wire system dramatically reduce vibration and cab noise.

Our tuned cab air suspension system, premium grade sound insulation kit, and durable routing and clipping wire system dramatically reduce vibration and cab noise.

Vocational-Specific Power

Under the hood, the CT681 is powered by a Cat CT Series Vocational Truck Engine with ratings specific to vocational truck applications and a horsepower/torque combination to tackle the toughest jobs.

Under the hood, the CT681 is powered by a Cat CT Series Vocational Truck Engine with ratings specific to vocational truck applications and a horsepower/torque combination to tackle the toughest jobs.

Automatic Shifting

Performance-matched with your engine to deliver rugged durability, smooth shifting and optimum power, the Cat CX31 Automatic Transmission will help you maximize your CT681's uptime, fuel economy and productivity. (Other transmission options are available.)

Performance-matched with your engine to deliver rugged durability, smooth shifting and optimum power, the Cat CX31 Automatic Transmission will help you maximize your CT681's uptime, fuel economy and productivity. (Other transmission options are available.)

Unmatched Support

Your CT681 comes with the best on-the-ground support team in the business. Your Cat dealer not only offers bumper-to-bumper service, but also can help you order the exact truck you need with expertise on custom options ranging from transmissions to suspensions and axles.

Your CT681 comes with the best on-the-ground support team in the business. Your Cat dealer not only offers bumper-to-bumper service, but also can help you order the exact truck you need with expertise on custom options ranging from transmissions to suspensions and axles.

  • Chasis
    • Set-forward axle, 114-inch bumper to back of cab (BBC)
    • 12.25-inch rail size: 120,000 psi yield strength
    • Above-rail radiator
  • Axles
    • Meritor & Dana options
    • 6x4 truck configuration
  • Front Suspension
    • Parabolic taper leaf for a smoother ride
    • Shock absorbers standard
    • Optional two-stage, multi-leaf, shackle-type with shocks
  • Rear Suspension
    • Hendrickson offerings: HMX, RT/RTE, RS, R & PriMaax
    • Chalmers standard & high articulation
    • Capacities from 40,000-85,000 lbs.
  • Fuel Tank
    • 80-, 100- & 120-gallon capacities
    • Single left or dual under cab/back of cab options
    • Aluminum alloy construction
  • Chassis
    • Integral Front Frame Extension (FFE)
  • Transmission
    • Cat CX31 Automatic Transmission
    • A variety of manual transmissions and the Ultrashift® Plus Vocational Transmission built by Eaton
  • On-board Technology
    • Vehicle Infotainment System
    • Bendix Tire Pressure Monitoring System
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