Caterpillar’s D5 is a bit of an unsung hero, straddling the gap between small and medium sized track type tractors in the Company’s product range. Rather than a child of the late 1960s, its heritage goes much further back. By Richard Campbell
In a bid to market an intermediate sized tractor to fill the void between the D4 and D6, Caterpillar once again revived the D5 name.
I say once again, because the origins of the Caterpillar D5 go way back in time to 1939 when the D5 model was first introduced.
The 1939 D5 was an offshoot of the D6-2H series on D4-7J undercarriage with a 60” gauge, and was known as the D5-9M series.
Powered by a six-cylinder Caterpillar D4600 diesel, (the same engine that was used in the first Cat DW10 motor scrapers), the 1939 Cat D5 is a very, very rare tractor as only forty six were ever manufactured and production was curtailed the same year it commenced, 1939!
This was due to low sales (an existing D6 of the day could do everything a D5 could and more) and the onset of WWII.
Only three of the forty six produced are known to still exist.
Rebirth – The 1960s
Caterpillar revived the D5 name in 1967 with the introduction of two new D5 models, a direct drive and a power shift version, both of which were available in either 60” or 74” gauges.
This “new” D5 had been developed from the very successful Cat D6B.
The D6B had been a good reliable tractor for Caterpillar but had been replaced by the more powerful D6C.
While the older D6B had been powered by the Cat D318 engine, the new D5 featured a naturally aspirated Caterpillar D333 diesel with a ninety three flywheel horsepower rating.
Marketed as just the right size for the contractor who needed to upsize from a D4 but couldn’t afford or really need the turbocharged D6C, the D5 was advertised internationally as the “tractor that filled the gap”.
Unlike its 1939 predecessor, demand for the new D5 turned out to be high, so much so that Caterpillar opened up production lines in Japan, Australia and France to cope with the worldwide demand.
Production in Australia and France ceased in 1972, but Japanese production continued on, and Japan became one of the prime sourcing locations for the model.
The latest D5 models are still manufactured in Japan to this day.
The new D5’s spawned a couple of offshoots, most notably the D5 LGP (low ground pressure), and the D5 LGP (low ground pressure).
D5 LGP’s were very popular in Asia, and featured a widened, lengthened track frame with very wide track shoes, either a traditional single bar grouser or a specially developed trapezoidal shoe which was self cleaning.
Caterpillar’s trapezoidal shoe had made its first appearance some years prior on the Company’s D6B LGP, a model only available in Japan at the time.
The D5 SA was a version especially developed for the agricultural sector and was a direct drive model only.
Usually fitted with an air conditioned cab, it featured full length fenders, larger muffler, extended air cleaner stack, six-way adjustable suspension seat and a strengthened drawbar.
It’s manual transmission also differed from the standard direct drive D5 in having more closely spaced gears to better adapt to whatever it was pulling.
Development never stops at Caterpillar and the D5 was no exception.
In 1977, an upgraded D5B was announced.
Most of the changes to the D5B were cosmetic – new deeper, sloping hood and improved operator deck and controls.
Mechanically the D5B differed very little from the earlier model other than the previous D333 engine was now known as the 3306, but still had the same 105 flywheel horsepower rating.
Available with a five-speed direct drive, or three=speed powershift transmission, and also in LGP and SA models the D5B proved to be just as good a tractor as the previous version and sales were again high.
The majority of D5B’s were manufactured by Caterpillar-Mitsubishi and exported all around the world.
The Nuts & Bolts – a 1970s Cat D5
Of conventional track type tractor layout, the D5 had a strong welded box maincase with welded parallel side frames.
Power was provided by a Caterpillar D333, non-turbocharged 6-cylinder diesel, putting out 105 flywheel horsepower. This engine was of the precombustion chamber type.
The transmission could be either a five-speed direct dive with a Cat oil clutch, or three speed Caterpillar powershift depending on the customer’s requirements
Multiple disc steering clutches and oil cooled contracting band brakes provided steering and stopping power.
Final drives were double reduction bull gear & pinion.
Each track frame was an all-welded inverted ‘U’ with a sliding equalizer bar to allow for track oscillation.
Track rollers and idlers were permanently lubricated with duo-cone seals and a choice of track shoe widths were available
The operator’s deck was flat and easily accessible with very good forward and rearward visibility over the contoured fuel tank
A deep cushion adjustable seat for the operator was standard.
Steering control was by hand lever (which disengaged the steering clutch) and brake pedal.
By the late 1960s, Caterpillar was manufacturing the bulk of their own attachments.
For the D5 you could have a choice of straight or angle blade, hydraulically controlled by the No.153 hydraulic system or, more rarely, by cable from a rear mounted No.25 PCU. Very few machines were delivered in this configuration and the cable option was discontinued by the mid-1970s.
Attachment supplier Balderson offered a hydraulically controlled U-blade for the D5.
Rear attachments included the No.5 ripper, Hyster winches, and of course, the previously mentioned No.25 cable control.
For added protection, the Fleco Corporation manufactured logging sweeps and a ROPS frame.
Operator comfort items included a ROPS or non-ROPS cab, with or without air conditioning, a demister, windscreen wipers and a heater.
Total production figures for the D5 and D5B are unknown but would be in the thousands.
The D5 and D5B were simple, uncomplicated tractors, very reliable. And they could be rebuilt time & time again.
You can’t really ask for more than that.
The New Zealand Connection
New Zealand Cat dealer Gough, Gough & Hamer sold many, many Caterpillar D5’s and D5B’s into the NZ marketplace.
Practically every iteration of these machines, including a D5-SA, is represented and private importations have only swelled the ranks further.
For the Model Collector
Although a common track type tractor, very few models have been issued of the D5 and none of the D5B.
Currently, the only model of the D5 available is a 1:50 offering from the Japanese company Grip-Zechin.
This is available in three different versions, the only difference being the blade and the colour of the tractor.
These are not ‘current standard’ models in terms of quality and have rubber tracks and no rear end attachment.
If you really must have one, they are available from Buffalo Road Imports in New York, USA and occasionally you can catch one on Ebay.
Expect to pay around US$75 for an example.
No Brief Specifications on this article as it’s an overview