Clark-Michigan wheel dozers

Image: An earlier model Clark-Michigan 280-II sits in a field awaiting its next call to duty. It is fitted with the standard S-blade, a factory cab (noted for being notoriously cramped) and rear tyre chains for extra traction.
Photo: Internet

Clark-Michigan was not the first manufacturer to offer a wheel type dozer.
That honour belonging to R.G. LeTourneau, which came up with the original
concept in the mid-1940s. By Richard Campbell.

Clark Equipment got into the earthmoving business in 1952 with the prime object of becoming a player in the business and, the following year, purchased the Michigan Power Shovel Company, a manufacturer of excavators and cranes.

To potentially increase its industry profile the company renamed itself Clark-Michigan. Inspired by LeTourneau’s ‘Tournadozer’, they adapted one of their new model wheel loaders, a 175 that had been introduced the previous year, to take a hydraulic bulldozer blade. And so, the first Clark-Michigan wheel dozer, the model 180 was born, making its industry debut in 1955.

The new machine was quite successful, finally giving potential purchasers a choice over LeTourneau. However, it became apparent to Clark-Michigan that some modifications were required to fully realise the potential of its new wheel dozer and this resulted in the development of a dedicated wheel dozer chassis, rather than the adaptation of an existing wheel loader chassis.

This was very much a step in the right direction and resulted in the introduction of the models 180-II, 280 and 380 wheel dozers the following year. These machines were well accepted by the industry, and found use in all manner of operations – from earthmoving to industrial stockpiling and forestry.

Interestingly, they were particularly well regarded in Europe where sales of Michigan wheel dozers outstripped those of LeTourneau!

One of the chief drawbacks of Clark-Michigan’s design, however, was the wide area required to turn and manoeuvre the machine, which required quite a bit of real estate with the rear-wheel steering (as did most of the other wheel loaders and dozers of that time period).

LeTourneau’s machines were superior in this respect, as its steering acted more like the skid-steer loaders of today, allowing a Tournadozer to execute a 180° turn in practically its own length. While this feature was very convenient, it was also very hard on tyre wear.

Articulated steering

The solution to this manoeuvrability problem was, of course, articulated steering, a concept first pioneered on Mixermobile’s ‘Scoopmobile’ range of wheel loaders in 1953.

This idea soon caught on, and by the mid-1960s most major manufacturers of wheel loaders and wheel dozers (including Clark-Michigan), were offering this form of steering on their machines. 

The only Michigan wheel dozer that never received articulated steering was the model 180 (which was, by now, in its 180-III version).

A choice of model sizes

During the time that Clark-Michigan manufactured wheel dozers, it built four distinct models: the rigid frame model 180, rigid and articulated frame models 280, 380 and their largest – the model 480.

The big 52-ton model 480, first introduced in 1958, featured a 14-foot blade and was popular with the large construction and mining industries. An articulated version of this machine appeared in 1965 and found immediate acceptance with its speed, blade capacity and agility.

The nuts and bolts

Offered with a choice of powerplant, (either Cummins or GM Detroit Diesel), the entire balance of the powertrain – torque converter, transmission, drivelines, differentials and axles – were all manufactured by Clark at its Benton Harbour, Michigan, facility.

On rigid frame machines, the operator was placed at the front of the machine in an elevated position where they had a good view of both corners of the blade.

Steering was via the rear axle and power assisted by two hydraulic rams. Full instrumentation was provided on panels either side of the steering column, directly in front of the operator.

Articulated machine versions placed the operator on the rear module, but with a similar ‘control tower’ view of the work area. These articulated machines had a steering angle of almost 30° to either side of centre, achieved by twin hydraulic steering rams, making the articulated versions far more agile than their rigid frame predecessors.

It is not known why an articulated version of the model 180 was never produced.

Optional bits and pieces

A cab could be specified on any of the models, but on the earlier rigid frame dozers, the narrowness of the cab caused a few grizzles. The articulated steer versions however, had quite a spacious cab with a heater, air purifiers or air conditioning that could be installed at the buyer’s request. Several optional tyre sizes and tread patterns were offered for all versions to suit local underfoot operating conditions.

Machines were normally supplied with a twin tilt-cylinder equipped straight blade, but of course other optional blades were available including a U-Blade, Coal Blade, and a specially designed blade for working on wood chip stockpiles.

Extra counterweight on the rear was required when equipped with either a coal or wood chip blade to achieve the correct machine balance.

Ateco offered several types of rear mounted ripper and scarifier to suit all versions as Michigan did not manufacture their own rippers.

All good things unfortunately come to an end. Regrettably, Clark-Michigan did not weather the downturn and recessions of the early 1980s very well. Dogged by falling sales and plummeting revenue, their scraper division shut up shop in 1981 followed closely in 1982 by the wheel dozer division.

This just left the wheel loader side of Clark-Michigan’s business, which was now run by Volvo following a partnership agreement which was formalised in 1985.

Clark-Michigan had disappeared entirely by the early 1990s.

For the model collector

Other than a couple of commercial diecast models offered in the 1970s by Dinky and Siku, the pickings are not good.

The Dinky Toys model is to 1:43 scale and represents a rigid frame model 280 version.

Due to the odd scale, it does not sit well in a collection of 1:50 scale diecasts.

However, the model by Siku, which is to 1:50 scale, represents a late production model rear wheel steer 180-III. Despite being intended for the toy market, it is quite adequately detailed for a model of this type and worth adding to a 1:50th scale collection.

The Dinky Toy model can be saved however, and I have completely stripped mine down, added loads of new detail forcing the scale, and repainted it – turning it into a model 380! It came out quite well.