Fleet # –
Year – 1997
Make – Mack
Model – RD688S
Body Style – 14
VIN/SN – 1M2P267CXVM032199
Odometer Numbers – 233909
Hours – 15483
Engine Make/Model – E7-350 12.0L turbocharged
Cyl – 6
Fuel Type – Diesel
Transmission Name – Maxitorque T2180, 18 Speed Extended Range Splitter type
Transmission Type – Manual
Single Axle/Dual Axle – Tandem Axle Dual Wheel
Tire Size/Type – 11R24.5
Tire Condition – Fair
Plow Size –
Dump Box Size –
Drivetrain – 6×4
GVWR –
Does the unit operate? – Yes
Does the vehicle start? – Yes
Are keys available? – Yes
Ownership Information – Title
Mechanical Condition – Fair
Mechanical Notes –
Body Condition – Fair
Body Notes – Previously a dump truck and was converted to a 14'Long dumping flatbed truck. Double frame is getting worn but is not cracked.
Interior Condition – Poor
Misc Info – The interior is poor to fair for its age with seat ware, view images.
The following general information is web-sourced and may contain variances from the subject unit:
This specific configuration is a heavy-duty, vocational powerhouse built for extreme reliability and high-capacity hauling. A 1997 Mack RD688S combined with a Mack E7-350 engine and a Maxitorque T2180 18-speed transmission is a quintessential "Mack Tough" setup, commonly deployed in demanding environments like construction, demolition, and infrastructure development.
Below is an in-depth breakdown of the truck, its powertrain, and its key features.
The Truck: Mack RD688S (Severe Duty Chassis)
The RD Series was Mack’s legendary severe-duty vocational workhorse before it was succeeded by the Granite line. The "S" designation typically denotes a Set-Back Front Axle, which shortens the wheelbase, shifts more payload weight to the front axle, and provides a much tighter turning radius on tight job sites.
- The Chassis: This model utilizes a heavy-duty, often double-framed steel chassis engineered to handle the severe twisting and torsional stress of off-road dumping and heavy flatbed hauling.
- 14' Dumping Flatbed Application: A 14-foot dumping flatbed makes this truck incredibly versatile. Unlike a standard dump truck, it gives you the flat surface area to haul palletized materials, heavy machinery, or construction tools, combined with the hydraulic hoist capability to instantly dump loose aggregate, debris, or materials.
- Axle and Drivetrain (6×4): A 6×4 configuration means it has three axles total (one steering front axle, two rear drive axles) with dual wheels on both rear tandems. This setup optimizes traction in deep mud, loose dirt, and rough terrain. It likely features Mack Camelback Spring Suspension, which is famous for its mechanical simplicity and extreme durability under maximum loads.
- Tires: Heavy-duty 11R24.5 tires offer excellent ground clearance and a taller sidewall, which acts as a secondary buffer against rugged off-road obstacles.
The Engine: Mack E7-350
The Mack E7-350 is widely considered one of the greatest, most durable inline-6 diesel engines ever built, routinely crossing the 1-million-mile mark when properly maintained. By 1997, it was transitioning into the "E-Tech" era, incorporating electronic unit pumps for improved fuel efficiency.
- Core Specifications:
- Displacement: 12.0 Liters (728 cubic inches)
- Configuration: Inline 6-Cylinder, 4 Valves per cylinder
- Aspiration: Turbocharged and Chassis-Mounted Air-to-Air Charge Cooled
- Horsepower: 350 HP @ 1800 RPM
- Torque: 1,277 lb-ft @ 1250 RPM
- Performance Characteristics: Mack engineered the E7 not for high-speed highway racing, but for pure low-end pulling power. It features a broad, flat torque curve that allows you to lug heavy loads out of steep, unpaved pits without stalling or constantly hunting for gears.
The Transmission: Maxitorque T2180 (18-Speed)
The Mack Maxitorque T2180 is a premier 18-speed heavy-duty manual transmission. It is highly favored over standard Eaton Fuller transmissions by pure Mack enthusiasts due to its proprietary structural design.
- Triple-Countershaft Design: Unlike most transmissions that use two countershafts, the Maxitorque utilizes three countershafts. This evenly distributes the massive engine torque across three gears instead of two, vastly cutting down on gear tooth stress, reducing frictional heat spikes, and dramatically extending the lifespan of the transmission bearings.
- Aluminum Casing: Built with a distinct triangular-shaped, high-strength aluminum housing. Aluminum passively radiates heat much faster than traditional cast iron, allowing the transmission to run significantly cooler under heavy loads without requiring fragile, external oil-cooler lines that are prone to rupturing on rough job sites.
- Extended Range Splitter Type: This transmission gives you 18 forward speeds and 4 reverse speeds. The "Splitter" allows you to split every single main gear choice into a "low" and "high" step. This micro-gearing is essential when moving a fully loaded dumping flatbed up heavy inclines or navigating soft ground, keeping the engine perfectly locked in its optimal 1400–1800 RPM power band.
Summary of Strengths
This truck is built purely as a mechanical brute. Because it relies on simpler 1997 electronic/mechanical systems (V-MAC control systems), it is exempt from modern, complex diesel exhaust emissions systems (DPF, DEF, SCR). This makes it highly reliable, cheaper to operate, and far easier to work on than modern vocational trucks.
Terms of Sale:
All sales are final. No refunds will be issued. This item is being sold as is, where is, with no warranty, expressed written or implied. The seller shall not be responsible for the correct description, authenticity, genuineness, or defects herein, and makes no warranty in connection therewith. No allowance or set aside will be made on account of any incorrectness, imperfection, defect or damage. Any descriptions or representations are for identification purposes only and are not to be construed as a warranty of any type. It is the responsibility of the buyer to have thoroughly inspected this item and to have satisfied himself or herself as to the condition and value and to bid based upon that judgment solely. The seller shall and will make every reasonable effort to disclose any known defects associated with this item at the buyer request prior to the close of sale. Seller assumes no responsibility for any repairs regardless of any oral statements about the item. Seller is NOT responsible for providing tools or heavy equipment to aid in removal. Items left on seller premises after this removal deadline will revert back to possession of the seller, with no refund.
