Komatsu D21P dozer

Easy to use with an old-school feel, this small dozer from Komatsu is ideal for rural block owners and small-medium sized contractors

  • Easily transported to jobs
  • Six-way angle/tilt blade
  • Produces a great finish
  • Quiet in operation
  • Economical to run

These D21s are great little machines, and are generally given to the rookie to learn on. They also used to be quite popular for rural block owners. The six-way angle tilt blade meant that even in the hands of a competent amateur, a good finish could be achieved with not too much effort. And being quite economical to run meant two or three 20-litre drums of diesel would be enough to get a heap of work done before needing a refill.

Another group of people that found them worth their weight in gold were the smaller contractors filling a mate’s block with a few loads of spoil, as the D21s were quiet and unobtrusive for neighbours.

For some reason, they don’t seem that numerous in urban contractor fleet these days, probably due to the lack of air-con and mp3 inputs, I reckon.

The operator’s seat

Controls on these are very basic, with an hour clock, fuel gauge and temperature gauges rounding off the instruments, along with the all important warning lights.

Steering is via two sticks that operate the clutches, assisted by foot pedals to brake each track, enabling tighter turns. On later models all steering is carried out via the foot pedals. Levers located alongside the arm rests control the various blade movements, engine revs, and two-speed travel direction.

Engine and power

These babies of the Komatsu stable are powered by a 40hp water-cooled four-cylinder diesel engine, which provides adequate power to push the little 3300kg machine along. You will generally find that when the going gets tough, the tracks will start to spin before it stalls out.

Performance and handling

I spotted a lonely looking pile of aggregate sitting on the other side of the yard begging to be flattened. As expected, the “little machine that could” made very quick work of spreading this out and with a few pushes and a bit of backblading, the work was complete – all way too soon.

Contemplating the machine later, I was left wondering why bulldozers like these seem to have gone out of fashion, as they are such great machines. Everyone seems to want an excavator these days, and to honest, looking at the trail of destruction that some amateur excavator drivers leave behind them, perhaps a small bully like the D21 would better suit their operating ability.

Repairs and maintenance

I’m told that tracks and chains are the main things to keep an eye on with these things, and this machine is in good order being built to a high standard. Regular servicing, and keeping an eye on transmission and other fluid levels should ensure a good hassle free run for a long time.


If you have a rural block then these machines are great for cutting in and maintaining farm roads. With a six-way angle/tilt blade and a little practice, a great finish can be achieved.

See a range of Komatsu dozers for sale.


Weight 3280kg
Engine Water-cooled diesel
No cylinders Four
Max rpm 2450rpm
Output 40hp/30.3kW
Overall length 3250mm
Overall width (with blade) 2680mm
Overall height to top of canopy 2185mm
Overall track length 1685mm
Travel speed 2.6-5.6 kph
Fuel tank 60L
Hydraulic tank 21L


Photography: Randolph Covich

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