Mack DM 686 S
Built: 1977-1977 · Series: DM
More machines from model year 1977
Not the right version? The data comes from vehicle registers holding many near-identical versions side by side. Photograph the data plate — we read make and type from it. Open the scanner e-mail address required
Mack DM – the collective page of the US construction truck built from 1966 into the 2000s, six- to twelve-cylinder engines, 7,800 to 13,530 kg unladen weight, 22,000 to 27,080 kg gross weight
This page gathers the versions of the Mack DM, which Mack Trucks built from 1966 into the 2000s as a heavy construction truck with a set-back front axle. Mack, founded in 1900 as Mack Brothers in Brooklyn, is known for the bulldog as its radiator mascot – a nickname British soldiers gave the rugged Mack trucks in the First World War – and remains one of the most storied American truck marques. The DM was engineered as a tipper and concrete-mixer chassis in tandem, tridem and four-axle configurations; the letter and number suffixes such as 600 S or 685 ST denote power and equipment variants, often fitted with Mack's own Maxidyne diesel, whose wide torque band required fewer gear changes than conventional engines.
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The register lists here 8 versions with six to twelve cylinders, unladen weights from 7,800 to 13,530 kg, gross weights from 22,000 to 27,080 kg, lengths from 6,470 to 7,350 mm and widths from 2,480 to 2,540 mm.
The DM was for decades the backbone of American construction for hauling gravel, concrete and bulk materials, and alongside the Kenworth W900 and Peterbilt 359 counts as one of the defining heavy US trucks of its generation, rugged enough for hard construction-site work and with a long service life on the used market.
On used examples, the condition of the frame after decades of tipper work, the axles and differentials, the Maxidyne engine for compression loss and oil consumption, and the tipper hydraulics and body count; parts run through the Mack network and dealers specialising in heavy US vehicles.
Sources: Kennwerte der Modelle Mack DM, Mack Trucks (Hersteller)
Technical data
Engine
| Cylinders | 6correct |
|---|
Dimensions and weights
| Length | 7,350 mmcorrect |
|---|---|
| Width | 2,500 mmcorrect |
| Wheelbase | 4,190 mmcorrect |
| Unladen weight | 8,760 kgcorrect |
| Gross vehicle weight | 27,080 kgcorrect |
Drivetrain and chassis
| Wheels | 6correct |
|---|
Frequently asked questions
How much does the Mack DM 686 S weigh?
The unladen weight is 8,760 kg.
What is the gross vehicle weight of the Mack DM 686 S?
27,080 kg.
What engine does the Mack DM 686 S have?
6 cylinders.
What are the dimensions of the Mack DM 686 S?
7,350 mm × 2,500 mm.
When was the Mack DM 686 S built?
Production years: 1977.
What to check before buying
- Check the hour meter against the service records — a replaced instrument is the most common gap.
- Compare the data plate and chassis number with the papers.
- Check the weights in the papers against the figures here — attachments change them.
- Ask about parts availability for this build year — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
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This page carries 9 individual figures for this model. They come from 1 recorded source; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
The technical data on this page comes from official vehicle registration records (RDW/Traficom), not from the manufacturer.
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Other models in this series
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Truck in 3D section
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